1 he Pan-Pacific Entomologist

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PAN-PACIFIC ENTOMOLOGIST

69(1): 1-11, (1993)

AN ANNOTATED CHECKLIST OF THE AQUATIC AND

SEMIAQUATIC DRYOPOID

COLEOPTERA OF CALIFORNIA

William D. Shepard 1

Department of Entomology, California Academy of Sciences,

San Francisco, California

Abstract.— All the species of aquatic and semiaquatic dryopoid Coleoptera known to occur in

California are listed. Genera with identification problems and undescribed species are indicated.

Factors that might influence the collection of species, such as ecological preferences and/or annual

occurrences of certain life stages, are cited.

Key Words.— Insecta, Coleoptera, Dryopoidea, Elmidae, Psephenidae, Dryopidae, Limnichidae,

Ptilodactylidae, Eulichadidae, Heteroceridae, distribution, habitat

Various families in the superfamily Dryopoidea have evolved to take advantage

of a diversity of aquatic and semiaquatic habitats. Most species of water-associated

dryopoids are found in streams and rivers. Others, however, are found in seeps

and springs, in lakes, in and on riparian vegetation, and in and on the mud and

sand margins of water bodies. California has a particularly rich dryopoid fauna

(Table 1), perhaps richer than any other area in North America. This undoubtedly

reflects the very diverse ecology of California, as well as its great north to south

length. Similar richness is seen in Plecoptera (Table 2) and in aquatic and semi¬

aquatic Hemiptera (Table 3), the only other orders for which appropriate distri¬

butional information is available. Even with this known richness, many new

species of aquatic insects are still being discovered in California. Another factor

adding to the richness of the dryopoid fauna is that various elements from the

dryopoid faunas of the Nearctic, Palaearctic, and Neotropical biogeographic regions

meet in the state. Nowhere else on the continent do these elements so combine.

This list was compiled because California, like many other areas, has seen an

upsurge in studies of stream ecology, water pollution, impact of logging, etc. These

studies have been hampered by workers not knowing just which species occur in

the state. Another part of the impetus for this checklist was requests for infor¬

mation on rare or endangered status of dryopoid species. 2 Only two previous

publications (Usinger et al. 1956, Brown 1972) have attempted to list California

dryopoids. Both are now out-of-date. Thus an updated list is warranted, although

many taxonomic problems remain; I am developing identification keys to the

species here.

The general ecology of aquatic and semiaquatic dryopoids has been well ad¬

dressed by Brown (1987). I have tried to indicate under each genus (family in two

cases) where the larvae and adults are most apt to be collected, at least as indicated

1 6824 Linda Sue Way, Fair Oaks, California 95628.

2 Most species for which more data were needed appeared rare because of insufficient collecting.

Only two, Dubiraphia brunnescens (Fall) and Microcylloepus formicoides Shepard, both from a single

locality, now deserve a protected status.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Table 1. Number of genera and species of aquatic and semiaquatic dryopoid Coleoptera in North

America and California. Number in parentheses is the percentage of the North American number.

Families

North America

California

Genera

Species

Genera

Species

Elmidae

14(54)

23 (24)

Dryopidae

3(75)

5(39)

Limnichidae

6(86)

13(42)

Psephenidae

3(50)

3(20)

Heteroceridae

6(67)

9(29)

Eulichadidae

1 (100)

Ptilodactylidae

2(67)

Totals

189

35 (63)

56 (30)

by my experiences. Most genera and species are rather catholic in microhabitat

choice(s). A few (i.e., Atractelmis, Dubiraphia brunnescens, Araeopidius, Thros-

cinus) appear to be very habitat-specific.

FAMILY ELMIDAE

Subfamily Larainae

Tribe Laraini

Lara LeConte 1852

Lara avara LeConte 1852

Lara gehringi Darlington 1929

These two species will probably be synonymized at a later date unless new

distinguishing characters can be discovered. As yet, there are no characters that

consistently separate the taxa. Larvae gouge soft submerged wood; adults are

typically on log-jams and debris piles, or on the undersides of undercut stream-

banks.

Subfamily Elminae

Tribe Elmini

Ampumixis Sanderson 1954

Ampumixis dispar (Fall) 1925

This species is quite variable in elytral color pattern, ranging from all red, to

having red maculae of variable size, to all black. The relatively long legs give it

a spidery look. Both larvae and adults occur in higher, cooler mountain streams.

Atractelmis Chandler 1954

Atractelmis wawona Chandler 1954

Once considered quite rare, this species is now known to be widespread in the

northern half of the state (Shepard and Barr 1991). Larvae and adults particularly

prefer submerged mosses, but they have been taken on roots of riparian vegetation.

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SHEPARD: DRYOPOID CHECKLIST

Table 2. Number of genera and species of Plecoptera (stoneflies) in North America and California.

Number in parentheses is the percentage of the North American number. Data from Stewart & Stark

(1988).

North America

California

Families

Genera

Species

Genera

Species

Capniidae

132

6(67)

29 (22)

Leuctridae

5(71)

10(19)

Nemouridae

6(55)

15 (23)

T aeniopterygidae

4(67)

9(28)

Chloroperlidae

9(75)

24 (33)

Peltoperlidae

3 (50)

6 (33)

Perlidae

4(27)

5(10)

Perlodidae

118

18 (62)

34 (29)

Pteronarcyidae

2(100)

3(30)

Totals

547

57 (58)

135 (25)

Cleptelmis Sanderson 1954

Cleptelmis addenda (Fall) 1907

Cleptelmis ornata (Schaeffer) 1911

These two species may be synonymized in the future unless good distinguishing

characters are found. Large enough population samples of each almost always

include individuals with the color pattern of the other species. I have found no

difference between the genitalia of the two species. Both the larvae and adults

occur most often in roots and moss.

Dubiraphia Sanderson 1954

Dubiraphia brunnescens (Fall) 1925

Dubiraphia giulianii (Van Dyke) 1949

These two species may be synonymized due to overlapping characters. Although

most individuals of each species are distinguished by different color patterns,

some specimens of D. giulianii have been found with the color of D. brunnescens.

Dubiraphia brunnescens appears to be restricted to Clear Lake (on willow roots),

Lake County, while D. giulianii occurs widely over the state. Larvae and adults

occur on roots of riparian vegetation, and on submerged macrophytes. Larvae

can be particularly hard to locate.

Heterelmis Sharp 1882

Heterelmis obesa Sharp 1882

Table 3. Number of genera and species of aquatic and semiaquatic Hemiptera in North America

and California. Number in parentheses is the percentage of the North American number. Data from

Menke (1979).

North America

California

Genera

36 (55)

Species

415

113 (27)

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

This very distinctive elmid has, so far, been collected in only a few spring-fed

canyon streams in the Mojave Desert of far southeastern California. It represents

one of the Neotropical lineages whose distribution just enters our area. Although

preferring submerged wood, larvae and adults may be taken in many microhab¬

itats.

Heterlimnius Hinton 1935a

Heterlimnius corpulentus (LeConte) 1874

Heterlimnius koebelei (Martin) 1927

One of the main characters distinguishing these species is the number of antennal

segments, H. corpulentus having 10 and H. koebelei having 11. The area of concern

is between the pedicel and the club—//, corpulentus has five segments there, while

H. koebelei has six. Unfortunately a number of specimens have been found having

10 segments on one side and 11 on the other side. Other antennal aberrations

have also been found. Both larvae and adults are commonly found in gravel. They

typically occur in cold, higher-elevation streams, where they replace Optioservus

spp.

Microcylloepus Hinton 1935a

Microcylloepus formicoideus Shepard 1990

Microcylloepus similis (Horn) 1870

This genus is in need of revision. Problems involve the numerous populations

isolated in springs and spring-fed streams on the east front of the Sierra Nevada,

and in the Basin and Range Desert. I presently find it difficult to understand the

morphological variation, both external and genitalic, between and within the

populations. A confounding factor is that many of these populations occur in

warm springs where the constant warm environment may be contributing to

morphological changes simply by altering developmental times. However, with

all these factors in mind, I still think that a third, as yet undescribed, species

occurs widely across an area south of Lake Mono from the east front of the Sierra

Nevada to the eastern border of Nevada. Both larvae and adults occur in a variety

of microhabitats in warm streams and springs.

Narpus Casey 1893

Narpus angustus Casey 1893

Narpus concolor (LeConte) 1881

Narpus concolor is far more variable in its size, shape, and size of maculae than

is N. angustus. Fortunately adults of these two species do not often co-occur. In

both species the larvae and adults are also generally not found occurring together

in any great number. I have yet to understand the microhabitat requirements of

the larvae. Narpus angustus adults are more typical of larger rivers in the various

mountains in the northwestern part of the state. They can be especially abundant

where bars of coarse gravel drop off into deep pools. Adults of N. concolor are

more often found a few at a time in the gravel and litter in small streams.

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SHEPARD: DRYOPOID CHECKLIST

Optioservus Sanderson 1954

Optioservus canus Chandler 1954

Optioservus diver gens (LeConte) 1874

Optioservus heteroclitus White 1978

Optioservus quadrimaculatus (Horn) 1870

Optioservus seriatus (LeConte) 1874

A particularly troublesome problem exists here in separating O. quadrimacu¬

latus from O. seriatus. Although individuals of both species appear different, no

consistent distinguishing character has been found. A similar problem exists with

O. divergens and O. heteroclitus, whose distinguishing characteristics seem only

to relate to size. The break between the sizes of the two species appears to me to

be rather artificial. Larvae and adults of all species are typically found in gravel

in warm to cool streams.

Ordobrevia Sanderson 1953

Ordobrevia nubifera (Fall) 1901

The characteristics of this species are more variable than originally described

and the variability may be controlled by water temperatures (Shepard 1992). Both

larvae and adults are typically found in gravel and under boulders in the faster

parts of streams.

Rhizelmis Chandler 1954

Rhizelmis nigra Chandler 1954

Occasional specimens are bimaculate or quadrimaculate. Quadrimaculate spec¬

imens with large maculae have the elytra appear banded with red. These specimens

strongly resemble Ampumixis dispar (which is very closely related) and some

Heterlimnius koebelei. Although widespread, this species is relatively uncommon.

Both larvae and adults seem to prefer coarse gravel substrates in cool, small-to-

medium sized streams. However, I have collected too few specimens to feel

confident that they do not like other microhabitats.

Zaitzevia Champion 1923

Zaitzevia parvula (Horn) 1870

A second, undescribed species is known to occur in the northcentral part of the

state. Larvae and adults occur in gravel in most streams.

Undescribed Genus

Recently specimens of an undescribed genus and species have been found in

cool mountain streams in northwestern California. This genus was first collected

(in Oregon and Washington) and recognized as new a few years ago by Cheryl B.

Barr. The California specimens appear to represent an additional species in this

new genus. This genus has close affinities with Cleptelmis, Ampumixis and Rhi¬

zelmis. Like these other genera, the larvae and adults of the new species show a

decided preference for aquatic mosses.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

FAMILY DRYOPIDAE

Dry ops Olivier 1791

Dryops arizonensis Schaeffer 1905

Adults occur on emergent material and readily come to lights at night. This

species has only been found along the border with Mexico (H. P. Brown, personal

communication).

Helichus Erichson 1847

Helichus columbianus Brown 1931

Helichus suturalis LeConte 1852

Larvae are now known to be terrestrial (Ulrich 1986); adults are found in many

stream microhabitats, but particularly associated with roots, and debris piles

containing leaves and sticks.

Postelichus Nelson 1989

Postelichus immsi (Hinton) 1937

Postelichus productus (LeConte) 1852

Habitat as for Helichus spp. Postelichus occurs in the warmer streams of the

southern part of the state, and north in the Coastal Mountains almost to the Bay

Area.

FAMILY LIMNICHIDAE

Adults are riparian. They are commonly found on vegetation overhanging the

water, on sand and mud bordering the water, and on various materials in the

strandline. Only a single larva has been collected in the Nearctic region. It was

in a cell under moss just at the edge of the water.

Subfamily Limnichinae

Tribe Limnichini

Limnichoderus Casey 1889

Limnichoderus lutrochinus (LeConte) 1879

Limnichoderus naviculatus (Casey) 1889

Lichminus Casey 1889

Lichminus tenuicornis (Casey) 1889

Eulimnichus C asey 1889

Eulimnichus analis (LeConte) 1879

Eulimnichus californicus (LeConte) 1879

Eulimnichus evanescens Casey 1912

Eulimnichus montanus (LeConte) 1879

Eulimnichus perpolitus (Casey) 1889

Limnichites C asey 1889

Limnichites foraminosus Casey 1912

Limnichites nebulosus (LeConte) 1879

Limnichites perforatus (Casey) 1889

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SHEPARD: DRYOPOID CHECKLIST

Tribe Bothriophorini

Physemus LeConte 1854

Physemus minutus LeConte 1854

Subfamily Cephalobyrrhinae

Throscinus LeConte 1874

Throscinus crotchi LeConte 1874

Adults are intertidal and found on mudflats in southern California.

FAMILY PSEPHENIDAE

Larvae are flattened, coppery in color, and more-or-less circular in outline; thus

their common name, water penny, is apt. Larvae are most commonly found on

rocks, but they may be on wood. Adults are terrestrial and riparian, and located

near the streams. Once mated, females crawl underwater to oviposit. Adults are

only found during the summer months.

Subfamily Eubrianacinae

Eubrianax Kiesenwetter 1874

Eubrianax edwardsii (LeConte) 1874

There may be more than one species in the state as one population has recently

been found pupating underwater. This habit is typical for some species from

Taiwan (Lee & Yang 1990). Eubrianax edwardsii pupates away from the stream.

Adults may be found on streamside vegetation or flying nearby.

Subfamily Eubriinae

Acneus Horn 1880

Acneus quadrimaculatus Horn 1880

Although only this species is definitely known from California, the other three

species in the genus may occur in the far northern part of the state. They are

known from southern Oregon (Fender 1951, 1962). Adults may be found on

riparian vegetation.

Subfamily Psepheninae

Psephenus Haldeman 1853

Psephenus falli Casey 1893

Although pupation normally occurs away from the stream, one population has

been found pupating underwater. Adults may be found on wet emergent parts of

boulders in fast currents.

FAMILY PTILODACTYLIDAE

The larvae are aquatic and occur in seeps, springs, and streams. The adults are

terrestrial and only occur during the late spring through summer months. Adults

are most commonly swept from riparian vegetation.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Anchycteis Horn 1880

Anchycteis velutina Horn 1880

Adult specimens that I have seen were from widely scattered locations across

northern California. Larvae are uncommon in the gravel of mountain streams.

Araeopidius Cockerell 1906

Araeopidius monochus LeConte 1874

Although occurring widely in northern California, more specimens are collected

in the Coastal and Cascade Mountains than in the Sierra Nevada. The single larva

that I have collected was in a muck-filled seep.

FAMILY EULICHADIDAE

Stenocolus LeConte 1853

Stenocolus scutellaris LeConte 1853

Larvae occur under rocks and in leaf packs in streams and rivers. Larvae are

common and have been collected widely across northern California. Adults have

been collected infrequently.

FAMILY HETEROCERIDAE

Larvae and adults of all species are riparian. They occur on mud and sand flats.

There they tunnel through the substrate, ingesting all material and digesting the

organic portion. They can be collected during the warmer months of the year.

There is disagreement over generic status within the family. Pacheco (1964)

elevated various species groups to genera. Miller (1988), however, prefers to retain

the single genus Heterocerus, and to recognize species groups only as such. Either

way, the morphological similarities between species make identifications difficult,

at best.

Tribe Augyliini

Microaugyles Pacheco 1964

Microaugyles mundulus (Fall) 1920

Tribe Heterocerini

Lanternarius Pacheco 1964

Lanternarius brunneus (Melsheimer) 1844

Lanternarius gemmatus (Horn) 1890

Lanternarius parrotus Pacheco 1964

Lanternarius sinuosus Pacheco 1964

Neoheterocerus Pacheco 1964

Neoheterocerus gnatho (LeConte) 1863

Dampfius Pacheco 1964

Dampfius mexicanus (Sharp) 1882

Lapsus Pacheco 1964

Lapsus tristis (Mannerheim) 1853

1993

SHEPARD: DRYOPOID CHECKLIST

Tribe Tropicini

Tropicus Pacheco 1964

Tropicus pusillus (Say) 1823

UNCERTAIN STATUS

Heterocerus Fabricius 1792

Heterocerus unicus Miller 1988

This species fits into the H. undatus group that Pacheco calls Dampfus.

Acknowledgment

I thank Norm Penny for commenting on an early draft of this paper. Addi¬

tionally, I thank two anonymous reviewers for suggesting many useful changes.

Special thanks go to Harley Brown, who introduced me to these marvelous insects.

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113-126.

Sharp, D. 1882. Haliplidae, Dytiscidae, Gyrinidae, Hydrophilidae, Heteroceridae, Pamidae, Geo-

rissidae, Cyathoceiidae. 1: 1—144. In Godman, F. & O. Salvin (eds.) Biologia Centrali-Amer¬

icana, Insecta. Coleoptera. R. H. Porter, London.

Shepard, W. D. 1990. Microcylloepus formicoideus (Coleoptera: Elmidae), a new riffle beetle from

Death Valley National Monument, California. Entomol. News, 101: 147-153.

Shepard, W. D. 1992. A redescription of Ordobrevia nubifera (Fall) (Coleoptera: Elmidae). Pan-

Pacif. Entomol., 68: 140-143.

Shepard, W. D. & C. B. Barr. 1991. Description of the larva of Atractelmis (Coleoptera: Elmidae)

and new information on the morphology, distribution and habitat of Atractelmis wawona

Chandler. Pan-Pacif Entomol., 67: 195-199.

1993

SHEPARD: DRYOPOID CHECKLIST

Stewart, K. W. & B. P. Stark. 1988. Nymphs ofNorth American stonefly genera (Plecoptera). Thomas

Say Found., 12: 1-460.

Ulrich, G. W. 1986. The larvae and pupae of Helichus suturalis LeConte and Helichus productus

LeConte (Coleoptera: Dryopidae). Coleop. Bull., 40: 325-334.

Usinger, R. L. (ed.) 1956. Aquatic insects of California, with keys to North American genera and

California species. Univ. Calif. Press., Berkeley.

Van Dyke, E. C. 1949. New species ofNorth American Coleoptera. Pan-Pacif. Entomol., 25: 49-56.

White, D. S. 1978. A revision of Nearctic Optioservus (Coleoptera: Elmidae), with descriptions of

new species. System. Entomol., 3: 59-74.

Received 6 July 1991; accepted 19 October 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 12-14, (1993)

NOTES ON THE ETHOLOGY OF

DICOLONUS SPARSIPILOSUM BACK

(DIPTERA: ASILIDAE)

Robert J. Lavigne

Entomology Section, Plant, Soil & Insect Sciences Department,

University of Wyoming, Laramie, Wyoming 82071

Abstract .—The presented data are the first biological and behavioral information recorded for

the genus Dicolonus. Prey, consisting of small Diptera, Hymenoptera and Coleoptera, are taken

in flight and manipulated during feeding with the predator’s fore tarsi. Males do not exhibit

courtship. Mated pairs take the tail-to-tail position, resting on stems of grass and twigs of

sagebrush.

Key Words. — Insecta, Diptera, Asilidae, Dicolonus sparsipilosum, bionomics

The genus Dicolonus is largely confined to the western United States, with only

two species barely reaching British Columbia (Adisoemarto & Wood 1975). Prior

to 1975, only two species had been described, D. simplex Loew, for which the

genus was erected in 1866, and D. sparsipilosum described by Back (1909). Three

additional species, D. medium Adisoemarto & Wood, D. nigricentrum Adisoe¬

marto & Wood and D. pulchrum Adisoemarto & Wood, were added to the genus

by Adisoemarto & Wood (1975). Since the erection of the genus, no biological

or behavioral data have been published for any species.

In late June 1977, a small population of D. sparsipilosum was studied on a

rangeland plateau located beneath Teton Point Overview in Grand Teton National

Park, Wyoming, USA. The area was bordered by a grove of quaking aspen ( Populus

tremuloides Michaux), and it was within this ecotone that the majority of D.

sparsipilosum individuals were encountered. The dominant vegetation within the

ecotone was Artemisia tridentata Nuttall and Agropyron sp.

Forage flights were initiated from vegetation, usually from a perch on a stem

of grass or sagebrush. Rarely did the robber flies return to the same perch twice

sequentially. The foraging flights covered a distance ranging from 7.6 to 61 cm.

When potential prey was observed, the whole body of the predator was turned

to face it. Prey was captured in the air and impaled on the mouthparts before the

asilid landed. It was usually manipulated, at least once, during feeding. During

this process, the robber fly grasped the substrate with its mid and hind tarsi, and

used its fore tarsi to rearrange the prey. Upon completion of feeding, the predator

moved its mouthparts in such a way that the emptied body fell in front of the

asilid at the feeding site.

Prey taken by D. sparsipilosum included one chironomid, and one muscid

(Diptera); one tenthredinid, two winged reproductive formicids, three Chalci-

doidea (Hymenoptera) and one Coleoptera. Insects larger than the predator were

not attacked.

Occasionally an asilid stopped in mid-flight, before making contact with the

potential prey, but usually the predator grasped the espied insect and returned to

the substrate. On four occasions, D. sparsipilosum was unable to subdue the prey

1993

LAVIGNE: ASILID ETHOLOGY

Figure 1. Mating pair of Dicolonus sparsipilosum.

it had captured; two such insects that escaped were cuckoo wasps (Chrysididae),

both being slightly smaller than the asilid, and more heavily sclerotized than any

of the subdued prey.

It is probable that males of D. sparsipilosum spend considerable time searching

for females, similar to that recorded for other studied species of robber flies (Dennis

& Lavigne 1975). Around midday and early afternoon, males were observed

making long flights of 1.2 to 1.5 m along grass corridors which occur between

groups of sagebrush plants.

No courtship was exhibited by males. The males flew at, and seized, both males

and females at random. These encounters sometimes included falling into the

vegetation while the pair were still grappling. If the seized fly was a male, contact

was broken and the two tended to fly off in opposite directions; if the seized fly

was a female, and she successfully eluded his grasp, the male flew off in pursuit

of her. Otherwise, mating took place on site.

Mated pairs were observed between 10:33 and 17:30 h. Temperatures at the

height the pairs were resting on vegetation ranged from 24.4 to 28.9° C. The pairs

take a tail-to-tail position, usually resting vertically with the female facing up¬

wards. Separation occurs when the male releases his claspers and walks away.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Three pairs, timed from the point when first observed, to completion, remained

en copula 26, 30 and 58 minutes. Only one mating of 49 minutes duration was

followed from start to finish. In this instance, the male flew into a clearing already

occupied by a female. When the female initiated a forage flight, the male flew up

and grappled with her. They fell into a clump of tangled grass, still struggling, and

copulation occurred at 13:14 h. The pair then crawled up a grass stem into a

partially shaded location, where the temperature was 24.4° C. At 13:16 h the pair

flew 61 cm landing on a sagebrush plant at a height of 25.4 to 30.5 cm. Almost

immediately, they flew 61 cm more, landing on a dead sage stem 30.4 cm above

the ground, with the female resting on the trunk and the male dangling in the air.

At 13:40 h, the female cleaned her eyes, and then her fore tarsi. The male started

struggling almost immediately, and after about 10 seconds attained the same perch

as the female, with their bodies forming an angle of approximately 140° (Fig. 1).

At 13:54 h, the male climbed on the female’s back; a short struggle ensued and

the former position was resumed. At 14:03 h, the male released his claspers and

flew 2.44 m. The female remained in place an additional 2 minutes before flying

away.

Acknowledgment

This article was published with the approval of the Director, Wyoming Agri¬

cultural Experiment Station as Journal Article No. JA 1662.

Literature Cited

Adisoemarto, S. & D. M. Wood. 1975. The Nearctic species of Dioctria and six related genera

(Diptera, Asilidae). Quaest. Entomol., 11: 505-576.

Back, E. A. 1909. The robber-flies of America north of Mexico, belonging to the subfamilies Lep-

togastrinae and Dasypogoninae. Trans. Am. Entomol. Soc., 35: 137-400.

Dennis, D. S. & R. J. Lavigne. 1975. Comparative behavior of Wyoming robber flies II (Diptera:

Asilidae). Univ. Wyoming Agr. Exp. Stn. Sci. Monogr., 30.

Received 10 August 1991; accepted 5 October 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 15-17, (1993)

TOADS (BUFO BOREAS BAIRD & GIRARD) OBTAIN NO

CALORIES FROM INGESTED

SPHENOPHORUS PHOENICIENSIS CHITTENDEN

(COLEOPTERA: CURCULIONIDAE)

Carl D. Barrentine

Integrated Studies/Biology, University of North Dakota

Grand Forks, North Dakota 58202

Abstract. —Ninety percent (865/962) of the billbugs ( Sphenophorus spp.) in 145 toad (Bufo boreas

Baird & Girard) fecal pellets were egested alive. Dead billbugs ( S. phoeniciensis Chittenden)

found intact in toad fecal pellets have an average weight and caloric content that was 1.4% (0.13/

9.06 mg) and 4.5% (0.225/5.049 kcal) greater, respectively, than that found for non-egested

billbugs. Toads ( B. boreas) derive no calories from billbugs (S. phoeniciensis ) that pass intact

through the digestive tract.

Key Words. — Insecta, Bufo boreas, Sphenophorus phoeniciensis, Sphenophorus venatus vestitus,

Curculionidae, weevils, billbugs, toads, fecal pellets, survival

Beetles (Coleoptera) constitute a major portion of the diet of western toads

(Bufo boreas Baird & Girard) (Barrentine 1991b). However, some beetles (Cur¬

culionidae: Sphenophorus spp.) can resist digestion, pass through the digestive

tract of the toad and emerge alive from fecal pellets (Barrentine 1991a, Barrentine

& Seeno 1988, Fair 1969). Although longevity is reduced for egested billbugs,

some individuals (S. phoeniciensis Chittenden) can live three weeks post-egestion

(Barrentine 1991c). Moreover, some individuals can survive three trips through

the digestive tract of the toad (Barrentine in press).

Not all billbugs survive digestion by toads. Barrentine (1991a) found that 32%

(1428/4406) of egested Sphenophorus spp. failed to emerge from fecal pellets

within four days. Because nearly all of these dead billbugs were intact (fully

articulated), it was suggested that toads may derive little, if any, nutrition from

ingested billbugs. Further, it was hypothesized that because egested billbugs were

rarely disarticulated by digestive processes, billbug mortality may be due to post-

egestive causes (i.e., death may result from an inability to escape entombment

from a desiccating pellet).

This study reports: (1) that 90% of the billbugs (Sphenophorus spp.) found in

the fecal pellets of the toad (B. boreas ) are egested alive, and (2) that toads (B.

boreas ) obtain no calories from billbugs (S. phoeniciensis ) that pass intact through

the digestive tract.

Methods

Survival.— Freshly egested fecal pellets were obtained from western toads for¬

aging from a fenced, 0.06 ha residential lawn [cultivar of Cynodon dactylon (L.)

Pers. x C. transvaalensis Burtt-Davy ‘Tifgreen’] in Bakersfield, California. Pellets

were collected daily from the turfgrass surface, in the evening (21:00-23:00 h) or

early morning (05:00-08:00 h), from mid-August to early September 1988, early

April to mid-July 1989, and July 1991. Individual pellets were immediately rinsed

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Table 1. Weight (mg) and caloric content (kcal) for egested and non-egested Sphenophorus phoenici-

ensis.

No.

samples

No.

bill-

bugs

(n)

Total

dry

weight of

samples

(mg)

Individual

dry weight,

X + SD

(mg/n)

Total

caloric

content of

samples

(kcal)

Caloric

content,

x + SD

(kcal/g)

Individual

caloric content,

X + SD

(kcal/n)

Egested

153

1405.7

9.19 + 0.12

7.415

5.274 + 0.031

0.0485 + 0.002

Non-egested

222

2010.8

9.06 + 0.06

10.152

5.049 + 0.039

0.0457 + 0.001

with water and egested billbugs ( S. phoeniciensis and S. venatus vestitus Chitten¬

den) were collected on a 1 mm mesh screen. These were transferred to vials and

dried for 24 h at 24-28° C and 35-45% RH. Vials were examined twice daily and

live billbugs were removed and tallied.

Calorimetry.— Live billbugs, S. phoeniciensis, were collected by hand from

infested turfgrass (between 21:00-23:00 h), immediately frozen, and then oven

dried at 68° C to constant weight (± 0.1 mg). Samples of dead billbugs (i.e., fully

articulated S. phoeniciensis that failed to emerge alive from fecal pellets) were

obtained from fecal samples preserved from an earlier study (see Barrentine 1991a).

These billbugs, preserved by freezing, were washed and then oven dried to constant

weight, as described above. Caloric content (kcal/g) for non-egested and egested

S. phoeniciensis was determined with a Parr oxygen bomb calorimeter (see Dim-

mitt & Ruibal 1980). Weight and caloric content of S. venatus vestitus is not

reported here because sample sizes were too small for reliable calorimetric analysis.

Results and Discussion

Survival. — A total of 962 billbugs (S. phoeniciensis and S. venatus vestitus) were

isolated from 145 toad pellets. Of these, 90% (865/962) were egested alive in

pellets. This survival frequency, significantly higher (% 2 = 192.44, df = 1, P <

0.001) than that reported in an earlier study (Barrentine 1991a), lends support

for the hypothesis that egested billbug mortality may be increased by an inability

to escape entombment from desiccating fecal pellets. In the earlier study, survival

was determined by counting the number of billbugs that emerged from fecal pellets.

In the present study, survival was not predicated on an ability to emerge from

fecal pellets because billbugs were removed from fecal pellets.

Calorimetry.— The weight and caloric content for egested and non-egested S.

phoeniciensis are shown in Table 1. Dead egested billbugs have an average weight

and caloric content that is 1.4% (0.13/9.06 mg) and 4.5% (0.225/5.049 kcal/g)

greater, respectively, than that found for non-egested billbugs. That the caloric

content for egested billbugs should exceed that found for non-egested billbugs was

unexpected. It may be possible that greater weight and caloric content of egested

billbugs is due to exogenous organic debris (i.e., mucoid intestinal secretions with

a high lipid content and undigested chitinous fragments from other arthropods)

that may have adhered to egested billbugs. Exogenous lipid would be difficult to

remove with water and would inflate the caloric content for egested billbugs.

Conclusion

Ninety percent of billbugs {Sphenophorus spp.) egested by toads {B. boreas ) are

egested alive in fecal pellets. The survival frequency for egested billbugs is mark-

1993

BARRENTINE: BILLBUG CONSUMPTION BY TOADS

edly higher than that reported in other studies. Weight and calorimetric data

indicate that billbugs ( S. phoeniciensis) found dead and intact in toad fecal pellets

show no evidence of digestion. Toads ( B. boreas) obtain no calories from billbugs

(S. phoeniciensis ) that pass intact through the digestive tract.

Literature Cited

Barrentine, C. D. (in press). Sphenophorus spp. (Coleoptera: Curculionidae) survive multiple passage

through the digestive tract of western toad. Coleopterists Bull., 47(1).

Barrentine, C. D. 1991a. Survival of billbugs (, Sphenophorus spp.) egested by western toads ( Bufo

boreas). Herpetol. Rev., 22: 5.

Barrentine, C. D. 1991b. Food habits of western toads {Bufo boreas halophilus) foraging from a

residential lawn. Herpetol. Rev., 22: 84-87.

Barrentine, C. D. 1991c. Post-egestive survival of Sphenophorus phoeniciensis Chittenden (Cole¬

optera: Curculionidae) egested by western toads. Pan-Pacific Entomol., 67: 135-137.

Barrentine, C. D. & T. N. Seeno. 1988. Billbugs ( Sphenophorus spp.—weevils) survive passage

through the digestive tract of western toads {Bufo boreas). Calif. Plant Pest and Disease Report,

7(1-4): 19-21.

Dimmitt, M. A. & R. Ruibal. 1980. Exploitation of food resources by spadefoot toads {Scaphiopus).

Copeia, 1980: 854-862.

Fair, J. W. 1969. Survival of weevils through the digestive tract of an amphibian. Bull. So. Calif.

Acad. Sci., 68: 260-261.

Received 12 November 1991; accepted 3 January 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 18-32, (1993)

LIFE HISTORY AND DESCRIPTION OF IMMATURE

STAGES OF PROCECIDOCHARES STONEI

BLANC & FOOTE ON VIGUIERA SPP. IN

SOUTHERN CALIFORNIA (DIPTERA: TEPHRITIDAE)

John F. Green, David H. Headrick, and Richard D. Goeden

Department of Entomology, University of California,

Riverside, California 92521

Abstract. —Procecidochares stonei Blanc & Foote is a facultatively multivoltine, stenophagous,

gall-forming fruit fly on Viguiera laciniata Gray and V. deltoidea Gray var. parishii (Greene)

Vasey and Rose (Asteraceae) in southern California. The latter host record is new; other published

host records are questioned. Eggs, first through third instar larvae, and puparia are described for

the first time. Galls formed on both host plants are described. The severe drought in southern

California during the last 5 years has reduced the densities of P. stonei on V. d. var. parishii.

Fly reproduction was restricted to one generation per year on the few host plant individuals that

thrived in favored sites where they received supplemental water (i.e., along drip lines of boulders

and margins of paved roads). Adult behaviors described include grooming, feeding, wing displays,

courtship, copulation and oviposition. Females typically lay eggs in clusters of two or more in

axillary buds. Larvae develop gregariously, mainly as two, but up to 13 per gall. Four species of

hymenopterous parasitoids are reported, the most common of which was Eurytoma sp. (Eury-

tomidae).

Key Words. — Insecta, Procecidochares, Viguiera, gall, immature stages, larval morphology, mat¬

ing behavior, parasitoids

This paper continues a series of life history studies on non-frugivorous species

of Tephritidae (Diptera) native to southern California. Procecidochares stonei

Blanc & Foote is one of several, little known species in this genus currently under

study (Goeden, Headrick, & Teerink, unpublished data). It was previously known

only from a taxonomic description of adults reared from galls on Viguiera laciniata

Gray, and from a published biology, as well as host records that we believe instead

apply to other species of Procecidochares. Adults of these species are morpholog¬

ically and biologically similar, but differ in their host-plant associations and sub¬

sequently their gall morphology. These undescribed species have been (Silverman

& Goeden 1980) or are currently under study; however, the present study based

on biological data collected from the type locality distinguishes P. stonei from its

related species, defines its host range, and resolves biological data from previously

published reports.

Materials and Methods

Galls in different stages of development were collected from plants at six dif¬

ferent localities in southern California. Galls on V. laciniata were sampled at Otay

Mesa and Otay Valley, in coastal, southwestern San Diego County. The Otay

Mesa site is the type locality for the species, and overlooks San Ysidro just north

of Tijuana, Mexico, at 45 m elevation. The Otay Valley site is nearby in San

Ysidro at 35 m elevation on a south-facing roadside slope.

Galls on V. deltoidea Gray var. parishii (Greene) Vasey & Rose were sampled

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

at Oriflamme Canyon in eastern San Diego County, at Mountain Springs in

southwest Imperial County, at Chino Canyon and along the Palms-to-Pines High¬

way above Palm Desert in Riverside County. Oriflamme Canyon is located at

665 m elevation, east of the Laguna Mountains, in a transition zone between the

Colorado Desert and high chaparral. The Mountain Springs site is in a rocky area

at 645 m, just north of the Mexican border; the Chino Canyon site is near the

entrance to the Palm Springs Aerial Tramway, at 725 m elevation. The Palms-

to-Pines Highway site is at 945 m above and west of Deep Canyon, on rocky,

barren slopes.

Samples were returned to the laboratory, measured and dissected. More than

500 galls were dissected during this study. All larvae and 10 puparia dissected

from these galls were preserved in 70% EtOH for scanning electron microscopy

(SEM). Puparia were placed in separate glass rearing vials stoppered with absor-

bant cotton and held in humidity chambers for adult emergence. Specimens for

SEM later were rehydrated to distilled water in a decreasing series of acidulated

EtOH. They were osmicated for 24 h, dehydrated through an increasing series of

acidulated EtOH, critically point dried, mounted on stubs, sputter-coated with a

gold-palladium alloy and studied with a JEOL JSM C-35 SEM in the Department

of Nematology, University of California, Riverside.

Up to 12 adults of each sex from each study site were point-mounted as vouchers

for the research collection of RDG; vouchers of immature stages were placed in

the collection of immature Tephritidae of DHH; reared parasites were placed in

a separate collection of parasitic Hymenoptera associated with Tephritidae be¬

longing to RDG. The description of immature stages follows the terminology and

format defined by Headrick & Goeden (1990), including the modifications ad¬

dressed by Headrick & Goeden (1991). Most adults reared from isolated puparia

were individually caged in 850 ml, clear-plastic, screened-top cages fitted with a

cotton wick and basal water reservoir and provisioned with a strip of yeast hy-

drolyzate and sucrose-impregnated paper toweling. The cages were used for lon¬

gevity studies and oviposition trials.

Virgin male and female flies obtained from emergence vials were paired in

clear-plastic petri dishes provisioned with a flattened, water-moistened pad of

absorbant cotton (Headrick & Goeden 1991) for direct observations, videotaping,

and still-photography of their general behavior, courtship, and mating. Pairs were

held together for at least 1 week, and observations were made throughout the day.

To quantify the effects of drought, galls were categorized as current-year’s, last-

year’s, and previous-years’ in a field survey at the Palms-to-Pines site in April,

1990, and gall abundance on 11 host plants was tabulated (Table 1). Each host

plant was measured and diagramatically divided into four quadrants along com¬

pass coordinates, within which the position of each gall was noted.

Plant names follow Munz (1974); insect names, Foote & Blanc (1963). Means

± standard errors are reported herein.

Taxonomy

Procecidochares stonei Blanc & Foote

Egg. — Smooth, white, cylindrical, elongate, and tapered on both ends (Fig. 1A). Length 0.4-0.5 [0.5

± 0.02] mm, width, 0.06-0.12 [0.08 ± 0.01] mm (n = 5). Apical end bears nipple-shaped pedicel

with few aeropyles (Fig. IB).

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Gall numbers and locations on 11 Viguiera laciniata plants at the Palms-to-Pines site in

April 1990.

Quadrant

Galls sampled

Previous years’

Last year’s

Current year’s

117

102

Totals

404

Third Instar Larva (fully grown).—White, barrel-shaped, tapered anteriorly, rounded posteriorly

(Fig. 2A). Gnathocephalon conical, flattened dorsally, rounded lateroventrally; slightly protruding

ventrally from prothorax (Fig. 2B), where it forms the mouth lumen at its anterioventral apex. Integ¬

ument surrounding lumen rugose ventrally, with 4 smooth petals dorsally (Fig. 2B—1). Paired tri-

dentate mouth hooks, directed ventrally (Fig. 2B—2), protrude from lumen. A laterally flattened

median oral lobe lies between mouth hooks (Fig. 2B—3), with no ventral papilla (we were unable to

see if it was attached basally to the labial lobe). Dorsad of mouth lumen, on anteriormost face of

gnathocephalon, are paired anterior sensory lobes (Figs. 2B—4, 2C), each with flattened lobes bearing

several sensory organs; a protruding, dome-shaped, dorsal sensory organ (Figs. 2B—5, 2C—1) is

adjacent to dorsomedial apex of each anterior sensory organ. On dorsolateral margin of each lobe lies

1 small sensillum (Fig. 2C—2). Each anterior sensory lobe bears 1 lateral sensory organ (Fig. 2C—3),

as a small, slightly raised papilla; a pit sensory organ (Fig. 2C—4), as a slightly raised area with an

invagination on its surface; and a terminal sensory organ (Fig. 2C—5) of several papillae on a slightly

raised area covering about 20% of the total lobe, not surrounded by a cuticular ring. A stomal sense

organ (Fig. 2B—6) lies ventrolaterad of each anterior sensory lobe, and is located on gnathocephalon

edge near the mouth lumen; each of these organs bears several small sensory papillae. Prothorax widens

posteriorly (Fig. 2B—P); integument smooth, relatively featureless, but bears 1 row of flattened sensilla

circumscribing its anterior margin. One pair of dorsolateral anterior thoracic spiracles on posterior

margin of prothorax (Fig. 2D); each normally consists of 2 or 3, dome-like spiracular papillae each

bearing a slit-like opening. Meso- and metathorax widen posteriorly, in similar appearance to abdom¬

inal segments. Typical abdominal segment bears a spiracular complex laterally along the midline (Fig.

2E); spiracles circular, do not protrude (Fig. 2E — 1); each spiracular complex with dome-like sensillum

anterior to its opening (Fig. 2E—2). Abdominal integument relatively smooth, featureless; abdominal

segments I—III widen posteriorly, reach maximum width at segments IV-VI; segments VII and VIII

narrow slightly, latter (caudal) bluntly rounded posteriorly, bearing posterior spiracular plates that

bear 3 oval rimae with spiracular slits (Fig. 2F— 1), an ecdysial scar (Fig. 2F—2) (found only on second

and third instars), and thom-like interspiracular processes on outer margins of each greatly reduced

and often indistinct spiracular slit (Fig. 2F—3).

Second Instar Larva. —White, barrel-shaped, tapered anteriorly, rounded posteriorly (Fig. 3A).

Mouth hooks tridentate (Fig. 3B— 1), median oral lobe present (Fig. 3B —2). Prothorax bears anterior

spiracles, each with 2 domed openings (Fig. 3C); lateral spiracles not observed; each posterior spiracular

plate bears 3 rimae (Fig. 3D— 1) and an ecdysial scar (Fig. 3D—2); interspiracular processes extremely

small (Fig. 3D-3).

First Instar Larva. — White, barrel-shaped, tapered anteriorly, rounded posteriorly (Fig. 4A): differs

from later instars with: mouthhooks bidentate (Fig. 4B — 1); median oral lobe rounded anteriorly (Fig.

4B—2); anterior sensory lobes directly above mouth lumen, their sensilla much reduced, with only

dorsal sensory organ (Fig. 4C—1) and terminal sensory organ (Fig. 4C—2) visible; anterior spiracles

absent; no lateral spiracles observed; posterior spiracles reduced, their plates bear two indistinct oval

rimae, each with no observable openings (Fig. 4D—1); interspiracular processes clearly visible, mul-

tibranched, and blade-like (Fig. 4D—2); no ecdysial scar present.

Puparium.— Black, barrel-shaped, gently tapering anteriorly, rounded posteriorly (Fig. 5A); 3.0-5.3

[4.2 ± 0.03] mm long ( n = 180), 1.3-2.7 [1.9 ± 0.02] mm wide (n = 201). Most third instar larval

structures retained in hardened and reduced state; gnathocephalon invaginated before pupariation,

not visible (Fig. 5B). Posterior spiracular slits flattened, more sharply defined than in third instar (Fig.

5C— 1); interspiracular processes reduced to barely distinguishable blemishes (Fig. 5C—2).

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

Figure 1. Egg of Procecidochares stonei : (A) cluster of three eggs; (B) detail of anterior end showing

two aeropyles.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Figure 2. Third instar larva of P. stonei : (A) habitus, anterior to the left; (B) anterior view of

gnathocephalon, 1—dorsal petals, 2—mouth hooks, 3—median oral lobe, 4—anterior sensory lobe,

5 —dorsal sensory organ, 6 —stomal sensory organ; (C) left anterior sensory lobe, 1—dorsal sensory

organ, 2—sensillum, 3—lateral sensory organ, 4—pit sensory organ, 5—terminal sensory organ; (D)

anterior spiracle; (E) lateral spiracular complex, 1 —spiracle, 2—sensillum; (F) posterior spiracular

plate, dorsal to right, 1—rima, 2—ecdysial scar, 3—interspiracular process.

Material Examined.— CALIFORNIA. SAN DIEGO Co.: San Ysidro, N of Tijuana, Mexico, 45 m,

27 Feb 1990, 12 Feb 1991, R. D. Goeden, V. laciniata Gray, galls containing immature stages.

Biology and Seasonal History

Gall. — Galls were collected from V. laciniata, the host plant at the type locality

(Fig. 6A), and V. deltoidea var. parishii, a new host recorded here for the first

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

Figure 3. Second instar larva of P. stonei : (A) habitus, anterior to left; (B) lateral view of gnathoceph-

alon, 1 — mouth hooks, 2 —median oral lobe; (C) anterior spiracle; (D) posterior spiracular plate, dorsal

to right, 1— rima, 2 —ecdysial scar, 3 — interspiracular process.

time (Fig. 6B). Viguiera are short, bushy, multibranched perennials with yellow

flower heads in the tribe Heliantheae of the Asteraceae. In southern California,

V. laciniata is found only in southern San Diego County on dry slopes below 760

m in coastal sage scrub and chaparral. Viguiera d. var. parishii is found in the

Colorado and East Mojave Deserts in sandy canyons and mesas below 1520 m

in creosote bush scrub (Shreve & Wiggins 1964, Munz 1974). The axillary bud

galls of P. stonei were found on the lower portions of previous growing season’s

branches of both host species. They lack or have short pedicels, and are dark

green, subspheroidal, and bear many bract-like leaves, especially apically (Fig.

6B).

Several features were measured on mature galls containing puparia from both

host species. Galls from V. laciniata measured 2.9-12.5 [7.9 ± 0.25] mm in width

and 3.9-15.2 [9.5 ± 0.3] in length (n = 80). Galls from V. d . var parishii measured

2.9-13.8 [7.1 ± 0.16] mm in width and 3.2-18.27 [8.8 ± 0.25] mm in length (n

= 149). These means were not significantly different (^-statistic width = 1.27,

length = 1.61; df = 227; P = 0.025). The single cavity within galls of V laciniata

measured 1.49-8.1 [4.5 ± 0.13] mm in width, and 2.8-9.9 [6.1 ± 0.18] mm in

length ( n = 80). Each cavity in galls from V. d. var. parishii measured 2.0-11.2

[4.76 ± 0.12] mm in width and 2.0-11.18 [5.9 ± 0.14] mm in length (n = 149).

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Figure 4. First instar larva of P. stonei: (A) habitus, anterior to left; (B) anterior view of mouth,

1 — mouth hooks, 2—median oral lobe; (C) anterior sensory lobe, 1 — dorsal sensory organ, 2—terminal

sensory organ; (D) posterior spiracular plates, dorsal end up, 1— rimae, 2—interspiracular processes.

Again, these means for cavity sizes were not significantly different (^-statistic width

= 1.75, length = 0.69; df = 227; P = 0.025).

Procecidochares stonei larvae develop gregariously within a gall. The number

of individuals per gall on V. laciniata was 1 to 13 averaging 2.5 ± 0.1 (n = 309),

and on V. d. var. parishii was 1 to 3 averaging 1.4 ± 0.04 (n = 192); these means

were significantly different (^-statistic = 7.7; df = 489; P = 0.025).

Egg. — Females begin to oviposit eggs, usually in clusters of two or more, shortly

after their emergence in mid-spring (i.e., late March though April). Eggs are in¬

serted into the axil between a branch and the base of a leaf petiole on the new

growth (Fig. 6C).

Larvae.— First instar larvae eclose shortly after oviposition and begin to feed

head-down in an axillary bud. The larva inhibits axillary branch elongation and

induces thickening (Fig. 6D). First instar larvae aestivate in the small, incipient

Figure 5. Puparium of P. stonei : (A) habitus, dorsal view, anterior to left; (B) anterior end, arrow

denotes right anterior spiracle; (C) posterior spiracular plate, dorsum to right, 1—spiracular slit, 2—

interspiracular process.

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Figure 6. (A) gall of P. stonei on type host, Viguiera laciniata', (B) gall of P. stonei on V. deltoidea

var. parishii; (C) cluster of three eggs laid in leaf axil on V. laciniata-, (D) immature gall on V. d. var.

parishii, (E) immature gall on V. d. var. parishii dissected to show first instar larva (arrow) in small

cavity; (F) saggital section of gall on V. laciniata containing a third instar larva and puparium; (G)

saggital section of gall on V. laciniata containing two puparia and showing the exit tunnel (arrow);

(H) adult female of P. stonei, (I) Adult female of Eurytoma sp., the most common parasite of P. stonei.

Bars = 1 mm.

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

galls (Fig. 6E) until rain stimulates plant regrowth in late-winter/early-spring, as

described for Procecidochares sp. on Ambrosia dumosa (Gray) Payne by Silverman

& Goeden (1980). Occasional late-summer rains also may stimulate a second

annual flush of plant growth and host and fly reproduction (Silverman & Goeden

1980). A sample of 27 galls collected from V. d. var. parishii at Chino Canyon

on 31 October 1991 yielded 25 dormant first instar larvae, 19 (86%) of which

were found singly in galls. Of 22 galls collected from V. laciniata at Oriflamme

Canyon in December 1989, 12 (55%) contained second or third instar larvae, and

10 (45%) held puparia (Fig. 6F). Larval growth proceeds rapidly through the second

and third stadia as host-plant growth resumes. Of 260 galls collected in February

1990 and 1991, from both host species, four (2%) contained first instar larvae,

eight (3%) had second instar larvae, 25 (10%) had third instar larvae, 234 (90%)

contained puparia (Fig. 6G); 10 galls contained both larvae and puparia. Before

pupariation, the third instar larva chews an exit tunnel in the gall wall out through

the leafy apex (Fig. 6G—arrow), as reported by Silverman & Goeden (1980).

Puparia.— By March 1990 and 1991, 71 (88%) of 80 galls contained puparia

(Fig. 6G); and flies had emerged from 38 (60%) of 64 of these puparia examined

more closely. In April 1990, a sample of 46 galls from the Palms-to-Pines site

contained only puparia, and flies had emerged from 46 (70%) of 66 puparia within

them. Puparia were oriented with their cephalic ends toward the exit tunnels. In

galls with more than one puparia, they were usually bound together with a thin,

clear, oily liquid. Adults emerged from puparia held in vials during late February

through mid-March.

Effects of Drought. — Viguiera d. var. parishii was common at the Palms-to-

Pines site, but 4 years of drought had taken their toll, as only 10-40% (visual

estimate) of each galled plant showed new growth. Most regrowth occurred on

plants that grew at the bases of boulders or rocky outcrops and thus benefitted

from additional water runoff. Eleven galled host-plants along a 500-m, east-west

transect averaged 72 ± 10 cm in diameter and 50 + 5 cm in height. Previous-

years’ galls, i.e., 2 or more years old, were found on all 11 plants and totalled

404, with the galls evenly distributed basally among the four quadrants (Table

1). Last-year’s galls were found on eight of the 11 (72%) plants and totalled 44,

with most concentrated in the southwest and southeast quadrants, and typically

located half way up the stems. Current-years’ galls were found only on four of

the 11 (36%) plants and totalled only 16, with most concentrated in the southeast

quadrant, and located distally half to two-thirds of the distance along the stems

(Table 1). These data suggested that as water-stressed plants put on less new

growth each year of the current drought, the numbers of galls also decreased

commensurately.

A few V. d. var. parishii at each desert site remained relatively healthy because

of their location along the driplines of boulders, as mentioned, or along paved

roads, where rain runoff also gave them an added measure of water. By locating

and ovipositing on these few relatively flush plants, at least a small population

of P. stonei had survived the drought conditions. Larval development is a fac¬

ultative process dependent on host-plant physiology (Freidberg 1984). Evidence

suggests that in years of extreme drought, first-instar larvae may remain dormant

for a year or more, until they die along with their hosts or incipiently infested

parts of their hosts (Silverman & Goeden 1980). The galls sampled at Chino

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Canyon in October, 1990, the fourth year of the drought, mentioned above,

contained only dormant first-instar larvae.

Adults. — A total of 79 females and 76 males were reared from isolated puparia.

Adults emerged during February and March 1990 and 1991, from galls collected

on V. laciniata at Otay Valley and Otay Mesa. Females are proovigenic (Fig. 6H).

Five, newly emerged females contained an average of 200 ± 12.1 (range 156—

216) ova in their ovaries. Adults emerge ready to mate, and females oviposit

shortly thereafter on the current branch growth.

The average longevity of 92 individuals obtained from V. d. var. parishii and

V. laciniata individually caged was 19.5 days. Forty-one males lived an average

of 24 days; five mated males lived an average of 23 days. Fifty-one females lived

an average of 16 days; 12 mated females lived an average of 16 days, and 10 of

those that were allowed to oviposit lived an average of 15 days. Death occurred

an average of 5.5 days after they ceased oviposition. The greatest longevity re¬

corded was 64 days for a male obtained from V. laciniata at Otay Mesa. Flies

from Otay Mesa on average lived longer, i.e., 39 days for males, 20 days for

females, and 30 days for all flies.

Wing Displays. — Adults of P. stonei are dark-bodied and have three dark,

transverse bands on their hyaline wings (Fig. 6H). At rest, the wings are usually

held parted at about 45°, with the wing blades supinated ca. 45°, such that their

anal margins touch the sides of the abdomen at ca. 160°. The medial margin of

the wings forms a straight line across the posterior margin of the body, and

completes a triangle with the costal margins of the wings (Fig. 6H). From this

position, the wings are synchronously and quickly extended forward and returned

through 30° to 45° arcs. This motion is repeated several times in 1-sec bursts,

which usually involve three repetitions. This general wing movement we call

“enantion,” a term derived from the Greek preposition meaning “against.” This

wing display is typical of Procecidochares (Headrick, unpublished data), all species

of which have a similar habitus. Resting or grooming adults of P. stonei spon¬

taneously displayed wing enantion; males also displayed enantion during court¬

ship. Moreover, both sexes visually oriented to nearby movement by turning and

facing the conspecific fly, predator, or other stimulus, and displaying rapid wing

enantion. The male apparently uses wing enantion to further stimulate the female

while gaining intromission (see below).

Males exhibited more variation in wing displays than did females, which only

displayed enantion. Wing display intensity depended on the time of day and state

of sexual excitment of the male. When a male approached a female for courtship,

his wings vibrated very rapidly, appearing as a sustained blur. Males rarely showed

asynchronous extension of their wings during courtship. The asynchronous display

involved one wing extending slightly forward, then returning to its resting position,

at which point the other wing similarly was extended. This wing movement was

much slower than the rapid synchronous thrusts of enantion.

Grooming.— Adults used their hind legs to clean all sides of their abdomen,

both sides of their wings, and the top of their thoraces. The hind legs were rubbed

together beneath the abdomen for cleaning. The foretarsi were used to clean the

head and also, were rubbed together for cleaning. The middle legs were used only

to help clean the fore and hind legs. Females exerted their ovipositors occasionally

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

to clean the eversible membrane and aculeus with their hind tarsi and the distal

parts of their hind tibia.

Feeding and Waste Excretion. — The mouthparts of both sexes pumped rapidly

and nearly continuously, regardless of other activities. The female mouthparts

pumped at about half the rate of the males. Adults readily drank water provided

to them in cages and arenas.

Courtship. — Males faced females and began asynchronous wing displays, start¬

ing at two to three extensions per sec and increasing in speed to a blur as excitation

of the males increased. Males trailed females while continuing their asynchronous

wing displays. Females answered with only one type of display (i.e., synchronous

wing extension without supination). When a male followed a female, he attempted

to mount her by jumping onto her dorsum. Although females were able to escape

the advances of a male by jumping away, males usually were able to grasp the

females and hang on. Once the male had mounted, females did not try to escape.

Copulation.— The male positioned himself on a female with the claws of his

foretarsi hooked basally around the costal veins of the females. His middle legs

wrapped around her abdomen near her thorax, and his hind legs were brought

underneath her abdomen near the base of the oviscape (= syntergostemite VII of

Norrbom & Kim 1988). Non-virgin males raised the oviscape at a 45° angle by

means of his hind legs; whereupon, the female in response immediately exerted

her aculeus; he then held his terminalia against the oviscape apex and the epan-

drium received the aculeus. Next, the female fully exerted her ovipositor, an

action that stretched the abdomen of the male to its limits. After a few minutes,

the female relaxed and the male assumed a normal copulatory position with his

forelegs on her abdomen near her thorax, his middle legs around her abdomen

near the ovipositor, his hind legs on the substrate, and the epandrium held against

the partially exerted, eversable membrane.

If the female did not exert her aculeus immediately, the male drummed his

hind legs against the venter of her abdomen and ovipositor. If this did not elicit

a response, he displayed wing enantion coupled with drumming. This behavior

was usually followed by the female exerting her aculeus. The aculeus was held in

place by the surstyli, with its tip raised, thus opening the ventral flap. The aedegus

was then inserted through the ventral flap into the oviduct while the ovipositor

was fully extended. As the ovipositor was slowly retracted, the aedeagus was

further thrust into the oviduct by pulsations of the abdomen of the male. Mated

pairs remained in copula from 20 min to 8 h, averaging about 2 h (n = 13), which

was longer than averages of 1 h observed for P. minuta (Snow) (Headrick, un¬

published data) and 30 min reported for Procecidochares sp. from A. dumosa

(Silverman & Goeden 1980). To terminate copulation, the male turned 180°, and

walked off the dorsum of the female and away from her while pulling his aedeagus

out of her aculeus. Once free, the male groomed and recoiled his aedeagus, while

the female also groomed herself. No post-mating activity other than grooming

was observed.

On one occasion, a male of a pair that had mated 5 days earlier was observed

trying to remount the same female. The male jumped on the female from the

front and turned around on her back to gain access to the oviscape; however, she

kept it covered with her wings so he could not reach down and grasp it with his

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

hind legs. He turned 360° twice while on top of her, and crawled down her side

twice while trying to grasp her oviscape. He then moved back on top of her and

tried to grasp her oviscape posteriorly with his hind legs. The female exerted her

aculeus as if to initiate coitus, and the male fell off. He did not attempt to mount

the female again.

Virgin males showed one of the few examples of naive mating behavior reported

among Tephritidae. During two separate trials, while a naive male was on top of

a female in the typical initial position, he began drumming with his hind legs

against her oviscape without raising it. The female exerted on command, but she

extended her aculeus so that the male couldn’t move posteriorly far enough to

engage the aculeus tip with his epandrium. This drumming by both males and

exertions of the aculeus by both females continued for nearly an hour in each

case, when finally each male successfully raised the oviscape and engaged the

aculeus, thus gaining intromission.

Oviposition. — Oviposition trials were carried out in the held and laboratory

with mated females from the above trials. Individual females were caged on

branches of V. laciniata or V. d. var. deltoidea obtained from the University of

California, Riverside, Botanic Garden. Viguiera d. var. parishii was unavailable

locally. The variety deltoidea is found naturally only in Baja California (Shreve

& Wiggins 1964). Females actively explored, and probed leaf axils of both test

species immediately after being caged on plants in the held, or with freshly cut

branches in the laboratory. When a female was ready to oviposit she turned away

from the stem and pushed the tip of her dehexed ovipositor into the axil between

a leaf base and stem (Fig. 6C). Except for a single group of two eggs laid near a

branch tip, females always chose axils on current season’s growth lower on branch¬

es near the main axis of the plant for oviposition. This corresponded with held

data on gall positions on plants.

Natural Enemies.— At least four species of parasitic Hymenoptera emerged

from puparia in rearing vials. A Eurytoma sp. (Eurytomidae) was the predominant

parasitoid at all locations. This solitary, internal larval-pupal parasitoid was re¬

covered from 300 puparia from all sample dates and locations (Fig. 61). Nineteen

individuals of a Halticoptera sp. (Pteromalidae) also were reared singly from

puparia collected at Otay Valley and Otay Mesa in 1991. A Tetrastichus sp.

(Eulophidae) was represented by 140 individuals recovered from 26 puparia from

all locations except Otay Mesa. A single male of a Spilochalcis sp. (Chalcididae)

was recovered from puparium from Mountain Springs. Five solitary, ectoparasitic

torymid larvae, one of which had an internal hyperparasite, were found feeding

on larvae of P. stonei in separate galls.

Host Range

Tauber & Tauber (1968) described the biology of P. stonei, which they had

identihed from a single, dead, teneral adult that had partly emerged from a gall

on Chrysothamnus viscidiflorus (Hooker) Nuttall. At that time, several unde¬

scribed species of Procecidochares were identihed as P. stonei or near (Silverman

& Goeden 1980). However, the gall Tauber & Tauber (1968) described and il¬

lustrated is quite different morphologically from the galls described from the type

host plant and type locality of P. stonei in the present paper. This gall also is

radically different morphologically from those of a Procecidochares sp. on A.

1993

GREEN ET AL.: PROCECIDOCHARES LIFE HISTORY

dumosa (Silverman & Goeden 1980) and at least five additional species of Pro-

cecidochares currently under study by Goeden, Headrick & Teerink (unpublished

data); at least two of these occur on another Chrysothamnus species, C. nauseosus

(Pallen) Britton. It only has a very small central cavity and is largely composed

of a series of overlapping, sessile, linear leaves (Tauber & Tauber 1968: figs. 1,

2), which is strongly reminiscent of certain cecidomyiid galls (Gagne 1989), and

unlike any other tephritid gall ( Procecidochares included) seen by RDG in Cali¬

fornia to date. In June, 1986, a sample of 62 galls from C. viscidiflorus like those

first described by Tauber & Tauber (1968) were collected in Deep Spring Valley,

Inyo County, dissected, and thoroughly examined by RDG (unpublished data).

Unfortunately, they contained only empty puparia, but these were similar in size

and color to those of the species of Procecidochares described by Tauber & Tauber

(1968) (i.e., smaller, narrower, and partially pigmented dark brown, only a few

completely black, unlike those of P. stonei described here). These data suggest

that the species studied by Tauber & Tauber (1968) was not P. stonei, but rather

the “ Procecidochares sp. A” of Wangberg (1980), which Novak et al. (1967)

reported as P. minuta.

Based on the present study, and published (Silverman & Goeden 1980) and

unpublished field and laboratory studies of other Procecidochares in California

(Goeden, Headrick, & Teerink, unpublished data), we suggest that the host records

in Wasbauer (1972) for P. stonei from Ambrosia dumosa, Corethrogynefilaginifolia

(Hooker & Amott) Nuttall, and Chrysopsis (as Heterotheca ) villosa (Pursh) Nuttall

are misidentifications of other Procecidochares species. Procecidochares stonei

apparently is restricted to Viguieria spp., which are found in a different tribe of

Asteraceae than are C. filaginifolia and C. villosa, both in the Astereae.

Acknowledgment

We thank J. A. Teerink for his technical assistance, A. C. Saunders of the

University of California, Riverside Botanical Gardens for identification of plants,

and G. Gordh, of the Department of Entomology, University of California, Riv¬

erside, for identification of the parasites. We also thank F. L. Blanc, A. L. Norrbom,

M. J. Tauber, and J. A. Teerink for their helpful comments on early drafts of this

manuscript.

Literature Cited

Foote, R. H. & F. L. Blanc. 1963. The fruit flies or Tephritidae of California. Bull. Calif. Insect

Surv., 7: 1-117.

Freidberg, A. 1984. Gall Tephritidae (Diptera). pp. 129-167. In T. N. Ananthakrishnan (ed.). Biology

of Gall Insects. Oxford & IBH Publ. Co., New Delhi, India.

Gagne, R. J. 1989. The Plant-Feeding Gall Midges of North America. Cornell University Press,

Ithaca, New York.

Headrick, D. H. & R. D. Goeden. 1990. Description of the immature stages of Paracantha gentilis

(Diptera: Tephritidae). Ann. Entomol. Soc. Am., 83: 220-229.

Headrick, D. H. & R. D. Goeden. 1991. Life history of Trupanea californica Malloch (Diptera:

Tephritidae) on Gnaphalium spp. in southern California. Proc. Entomol. Soc. Wash. 93: 559—

570.

Munz, P. A. 1974. A Flora of Southern California. University of California Press, Berkeley.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Norrbom, A. L. & K. C. Kim. 1988. Revision of the schausi group of Anastrepha Schiner (Diptera:

Tephritidae), with a discussion of the terminology of the female terminalia in the Tephritoidea.

Ann. Entomol. Soc. Am., 81: 164-173.

Novak, J. A., W. B. Stoltzfus, E. J. Allen, & B. A. Foote. 1967. New host records for the North

American fruit flies. Proc. Entomol. Soc. Wash., 69: 146-148.

Shreve, F. & I. L. Wiggins. 1964. Vegetation and Flora of the Sonoran Desert, Vol. 2. Stanford

University Press, Palo Alto, California.

Silverman, J. & R. D. Goeden. 1980. Life history of a fruit fly, Procecidochares sp., on the ragweed

Ambrosia dumosa (Gray) Payne, in southern California (Diptera: Tephritidae). Pan-Pacif. En¬

tomol., 56: 283-288.

Tauber, M. J. & C. A. Tauber. 1968. Biology of the gall-former Procecidochares stonei on a composite.

Ann. Entomol. Soc. Am., 61: 553-554.

Wasbauer, M. W. 1972. An annotated host catalog of the fruit flies of America north of Mexico

(Diptera: Tephritidae). Calif. Dept. Agric., Bur. Entomol., Occas. Papers, 19.

Wangberg, J. K. 1980. Comparative biology of gall-formers in the genus Procecidochares (Diptera:

Tephritidae) on rabbitbrush in Idaho. J. Kansas Entomol. Soc. 53: 401-420.

Received 25 November 1991; accepted 5 October 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 33-35, (1993)

EXTENDED DEVELOPMENT OF

POLYCAON STOUTII (LECONTE)

(COLEOPTERA: BOSTRICHIDAE)

Steven J. Seybold 1 and David L. Wood

Department of Entomological Sciences, University of California,

Berkeley, California 94720

Abstract.— Polycaon stoutii (LeConte) adults emerged from wood cabinets 21 to 24.5 years after

they were installed in homes. The cabinets were likely white ash, Fraxinus americana L. This

represents the first record of this bostrichid from an eastern hardwood.

Key Words. — Insecta, Polycaon stoutii, extended development, Fraxinus americana

In September 1986, a homeowner in Berkeley, California (1375 Summit Rd.,

Berkeley, California, Alameda Co.) contacted us after observing large black beetles

emerging from ash cabinetry. Two adjacent homes with similar cabinetry were

constructed by the same builder in 1967 and beetles had been observed emerging

from cabinetry by homeowners of both structures. The cabinetry in one of the

structures had been varnished, but the cabinetry in the second structure had been

treated with linseed oil. We collected boards from the varnished cabinets, sawed

them into smaller lengths, and placed them into rearing containers. We noted

that all emergence tunnels were through the finished surface indicating that infested

lumber was used to manufacture the cabinets. In July 1987 an adult (18 mm in

length) emerged from a board in a rearing container and was identified as

Polycaon stoutii (LeConte). A second adult of the same species, 21.5 mm in length,

emerged between June 1988 and March 1991.

The black polycaon, Polycaon stoutii, occurs in British Columbia, the Pacific

coast states, and Arizona (Ebeling 1975, Fisher 1950). It is a wood-boring insect,

generally attacking non-coniferous woods used for building material, furniture,

and cabinetry (Doane et al. 1936). It will also develop in the wood of fruit trees

and ornamentals (Essig 1958). Normally, the larvae require one to several years

to complete development (Linsley 1943b). However, Middlekauff (1974) reported

three instances of extended life cycles ranging from 8 to 22 years. As is often the

case with other pests associated with wood in service, this species is transported

in wood products to regions where it is not indigenous [e.g., collection record

from a redwood dresser in Tennessee and from a mahagony table in Texas (Fisher

1950)].

There is some question in the literature regarding the condition of the host

required for oviposition by P. stoutii. It appears that its usual habit is to attack

dead and occasionally living trees (Doane et al. 1936, Essig 1958). However,

Doane et al. (1936) imply that adults are capable of ovipositing in curing plywood

and lumber in warehouses. Linsley (1943b) states that P. stoutii is “not known

to infest finished products after manufacture nor to re-infest materials in which

1 Current address: Forest Service, United States Department of Agriculture, Pacific Southwest Re¬

search Station, Berkeley, California 94701.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

it has previously been breeding”; furthermore, “emergence, even after long periods

of time, is generally regarded as evidence that the product was infested before

manufacture.” However, Mallis (1982) states that P. stoutii will also attack cured

hardwoods in lumber yards, buildings in mountainous areas, and furniture and

other wood products (probably prior to finishing).

In this case, we consider that oviposition in the finished cabinetry from indig¬

enous sources of beetles (e.g., firewood, moribund trees, etc.) was an unlikely

source of this infestation. Besides the low probability of oviposition occurring

through two different finished surfaces, individuals of this insect species were

observed simultaneously emerging from cabinetry in both adjacent homes. Be¬

cause the cabinets were built into the homes during construction in 1967, it is

likely that both specimens developed over the 21 and 22 to 24.5-year periods,

respectively.

Surprisingly, the extended developmental period in the seasoned wood did not

seem to affect the vigor of the individuals that emerged. If length is taken as an

indicator of health of the specimen, the lengths of the two (18 mm and 21.5 mm)

are at the extreme end of the normally expected range (11 mm to 22 mm: Ebeling

1975). It is likely that development in this nutrient-poor environment was aided

by microbial symbionts.

The infested wood was identified as white ash (solid), either Oregon ash, Frax¬

inus latifolia Bentham, or white ash, Fraxinus americana L. These two species

are indistinguishable based on wood anatomical characteristics. However, in con¬

trast to F. americana, F. latifolia is rarely cut for commercial lumber. Thus, it

seems probable that the infested lumber is F. americana. Although we have no

detailed history of the origin of the lumber used to construct the cabinetry, the

infestation probably was initiated in lumber after it was transported from the East

to the West coast. Fraxinus americana is normally shipped following kiln drying

to lower the moisture content thereby reducing the cost of shipment. This treat¬

ment would have killed any insects present in the raw lumber. We believe that

this is the first host record for P. stoutii from an eastern hardwood species. Mid-

dlekauff (1974) also reported a case where P. stoutii was collected from “ash”

cabinetry, but the species status of the wood sample was not determined.

We conclude in this instance that P. stoutii can undergo a greatly extended

developmental cycle rivaled only by the Buprestidae (Linsley 1943a, Smith 1962)

and termite queens (Krishna & Weesner 1969) and can continue its development

in finished wood products (Middlekauff, 1974).

Acknowledgment

We thank homeowner Annette Shapiro for providing us with this interesting

case study; A. P. Schniewind (retired), Forest Products Laboratory, University of

California, Richmond, California for wood identification; and J. A. Chemsak, J.

T. Doyen, and J. Santiago-Blay, Department of Entomological Sciences, Univer¬

sity of California, Berkeley, for assistance with species determination.

Literature Cited

Doane, R. W., E. C. Van Dyke, W. J. Chamberlain & H. E. Burke. 1936. Forest Insects. McGraw

Hill, New York.

1993

SEYBOLD & WOOD: BOSTRICHID DEVELOPMENT

Ebeling, W. 1975. Urban entomology. Univ. of California Division of Agricultural Sciences, Berkeley,

California.

Essig, E. O. 1958. Insects and mites of western North America. Macmillan, New York.

Fisher, W. S. 1950. A revision of the North American species of beetles belonging to the family

Bostrichidae. USDA Misc. Publ., 698.

Krishna, K. & F. M. Weesner. 1969. Biology of termites. I. Academic Press, New York.

Linsley, E. G. 1943a. Delayed emergence of Buprestis aurulenta from structural timbers. J. Econ.

Entomol., 36: 348.

Linsley, E. G. 1943b. The recognition and control of deathwatch, powderpost, and false powderpost

beetles. Pests and Their Control, 11:11-14, 23-26.

Mallis, A. 1982. Handbook of pest control (6th ed.). Franzak & Foster, Cleveland, Ohio.

MiddlekaufF, W. W. 1974. Delayed emergence of Polycaon stoutii Lee. from furniture and interior

woodwork. Pan-Pacif. Entomol., 50: 416-417.

Smith, D. N. 1962. Prolonged larval development in Buprestis aurulenta L. (Coleoptera: Buprestidae).

A review with new cases. Can. Entomol., 94: 586-593.

Received 6 May 1992; accepted 20 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 36-40, (1993)

ERNOBIUS MOLLIS (L.) (COLEOPTERA: ANOBIIDAE)

ESTABLISHED IN CALIFORNIA

Steven J. Seybold 1 and Jonathan L. Tupy 2

Department of Entomological Sciences, 201 Wellman Hall,

University of California, Berkeley, California 94720

Abstract.— The bark anobiid, Ernobius mollis (L.), was collected in Oakland, California; thus

providing the first unequivocal North American record of this species west of Texas. Adult and

larval E. mollis were collected from a laboratory cage containing the originally infested branches

over a nineteen-month period, and adults were observed in copulo, suggesting re-infestation of

the same bark-covered wood. Because E. mollis is generally considered among pests of structures

in Europe and the southern hemisphere, the literature pertaining to E. mollis is reviewed here

in the event that it may assume economic importance in California.

Key Words.— Insecta, Ernobius mollis, California

We have found the bark anobiid, Ernobius mollis (L.) (Coleoptera: Anobiidae)

in branches cut from a Norway spruce, Picea abies (L.) Karsten, planted as an

ornamental tree (diameter at breast height 30.5 cm) in a homeowner’s yard in

Oakland, California. Adults and larvae were also observed in the stem of the

declining, yet live, tree from which the branches were cut. In both the stem and

branches, the adults and larvae were clustered together with adults and larvae of

the Monterey pine engraver beetle, Ips mexicanus (Hopkins) (Coleoptera: Scolyti-

dae). In the cut branches, adult and larval E. mollis were also intermixed with

adults and larvae of the California five-spined ips, I. paraconfusus Lanier. Larval

E. mollis had excavated extensive tunnels in the phloem and bark that contained

uniformly shaped, dark fecal pellets. The mines deeply scored and sometimes

entered the xylem.

Branches (diameter 3-7 cm) containing larvae, pupae, and adults were collected

on 22 Feb 1990 and placed into a laboratory cage at room temperature (16.1° C-

29.4° C). Adults began emerging from the branches immediately, and 28 insects

emerged over a two-month period with a peak emergence occurring between 15

Mar 1990 and 1 Apr 1990. Additional adults, many of which were alive, were

recovered from the cage on the following dates: 17 Nov 1990 (1); 27 Apr 1991

(16); 11 May 1991 (3); 8 Jun 1991 (9); 13 Oct 1991 (42); 18 Jul 1992 (543,

including 97 live beetles); 30 Jul 1992 (114, including 88 live beetles); 15 Sep

1992 (115, including 22 live beetles); and 24 Sep 1992 (4, including 1 live beetle).

In addition, larvae were found on the bottom of the same cage on: 18 Jul 1992

(37, including 19 live larvae); 15 Sep 1992 (6, all alive); and 24 Sep 1992 (2, both

alive). On 18 Jul 1992, adults were observed mating on the bark surface, and on

30 Jul 1992 eight different pairs were recovered in copulo from the cage. Living

larvae were also recovered from the floor of a second cage containing stem material

from the same tree, thirteen months after that material was placed into the cage.

This long period of collection of live adults suggests either (1) delayed emergence

1 Current address: Forest Service, United States Department of Agriculture, Pacific Southwest Re¬

search Station, P.O. Box 245, Berkeley, California 94701.

2 Current address: Tularik, Inc., 270 East Grand Avenue, South San Francisco, CA 94080.

1993

SEYBOLD & TUPY: ERNOBIUS MOLLIS IN CALIFORNIA

or (2) re-infestation of the same bark-covered branches or stem material; obser¬

vation of mating adults seems to suggest the latter.

Ernobius mollis, referred to as the bark anobiid (Tooke 1946), pine bark anobiid

(Hockey 1985), or the false furniture beetle (Bevan 1987) and as the “Weiche or

Feinhaarige Nagekafer or Klopfkafer” (Gr: soft or finely haired, gnawing or knock

beetle) (Schmidt 1971), has long been included among the pests of structures in

Europe (Kemner 1915; Trag&rdh 1938; Bletchley 1964,1967). Hockey (1985) states

that E. mollis is univoltine with adults present in spring and early summer. Its

biology in Europe has been studied by Gardiner (1953); she lists coniferous soft¬

woods, such as Larix decidua Miller, P. abies, Pinus canariensis C. Smith, Pinus

nigra Arnold, Pinus pinaster Aiton, Pinus radiata David Don, Pinus sylvestris L.,

Pinus taeda L., and Pseudotsuga taxifolia (Poiret) Britton [= menziesii (Mirbel)

Franco] as recorded hosts. Ernobius mollis does not appear to attack hardwoods.

Although there are reports of damage to flooring, veneer, and furniture, E. mollis

appears to be most often associated with bark-covered timbers installed or stored

in new structures, rustic cottages, museums, or sawmill yards. Tooke (1949),

Bletchley (1967), and Schmidt (1971) suggest that floorboards, veneers, and fin¬

ishings might be damaged when E. mollis emerges from underlying support pieces

containing bark. Ernobius mollis has even been noted to attack unfinished edges

and knots in rough sawn boards, presumably deriving nourishment from the

occluded bark around the knot (Tooke 1946, Bletchley 1967). Dominik (1958)

has observed that several generations of E. mollis will attack the same piece of

bark-covered wood. However, it is doubtful that this species can reinfest wood

products once the bark has been removed or depleted by infestation. Because of

its requirement for bark, which is rarely present in large quantities in modem

home construction, Bletchley (1965) states that an active Ernobius infestation,

although uncommon, is chiefly found in comparatively new homes.

In the forest, E. mollis is prevalent in burned timber (Clarke 1932) and has

been noted in dead standing trees up to 20.0 cm in diameter (Kelsey 1946). In

contrast with our observation in Oakland, Tooke (1946) states that E. mollis does

not attack living trees or green wood. In fact, he found that E. mollis had a

preference for dry seasoned timber and would only attack wood in timber stacks

that had been seasoned for over six months. However, Tooke (1949) reports that

infestations may commence in dead branches of living trees and spread down

into the main tmnk. In Great Britain, Bletchley (1967) indicates that the natural

habitat for E. mollis is “recently dead softwood trees or fallen branches where

the bark is still present,” but Bevan (1987) notes that E. mollis causes obvious

damage symptoms but has slight or no effect on “pole and older” sized conifers.

In France, Roques (1983) describes damage by E. mollis to cones of the exotic

species, Sequoiadendron giganteum Buchholz and P. menziesii.

Unger (1986) reports that larval damage is almost always restricted to the

“Rinde” (Gr: inner and outer bark), giving the bun-shaped (Kelsey 1946) or lentil¬

shaped (Schmidt 1951) fecal pellets a brown color. Gardiner (1953) also states

that the larva is restricted to the bark, but that the pupal cell penetrates the outer

part of the wood. However, most authors (Clarke 1932; Kelsey 1946; Tooke 1946;

Schmidt 1951, 1971; Dominik 1958; Bletchley 1967; Hickin 1968; Hockey 1985)

suggest that the feeding by late stage larvae includes the xylem, which is consistent

with our observations in California. Feeding by larvae results in frass that contains

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

both dark- (from the bark) and light-colored (from the sapwood) fecal pellets

(Bletchley 1967). Schmidt (1971) states that fecal pellets from bark feeding are

egg-shaped, although those from sapwood feeding are lentil-shaped. Microscopic

examination of the fecal pellets can be used as a diagnostic character to differentiate

damage by E. mollis from more economically important species (Schmidt 1951).

According to Schmidt (1971) and Unger (1986), occurrences of is. mollis in Europe

have been more frequent in recent years. However, Becker (1984) characterizes

the damage as “relatively harmless.” Preventative treatment involves timely re¬

moval of bark from wood intended for service in building construction (Bletchley

1967, Hockey 1985, Unger 1986).

From its native distribution in northern Europe, E. mollis has been introduced

into the North American continent and the southern hemisphere (Tooke 1946,

Casimir 1958, Hickin 1968). Tooke (1946) describes the entry of E. mollis into

South Africa in 1937 via packing crates containing machinery for a sawmill. The

crates were constructed of pine slabs that had a considerable surface area of bark,

but during crate construction the infested, bark-covered regions of the slabs were

turned inward and not readily visible. From the sawmill, the insect spread rapidly

throughout the country in infested products.

Sometime during this century E. mollis became established in eastern North

America (Craighead 1950, Simeone 1962) with collection records from Ontario

to Nova Scotia in the north, and Texas to Florida in the south (White 1982).

Simeone (1962) noted that although E. mollis appears to be quite abundant in

the major insect collections in eastern North America, it was reported in only one

instance in a survey of structural pest cases in New York state. Although histor¬

ically it appears to have been of little significance in structures in North America,

during the last decade it has been frequently found damaging bark-covered logs

used in home and cabin construction in New York (J. B. Simeone, personal

communication). In South Africa, New Zealand, and Australia, where P. radiata

has been planted extensively and used for building material, E. mollis has been

(Casimir 1958), and continues to be (Hockey 1985), a damaging pest of timber

and occasionally buildings. In an examination of specimens at the California

Academy of Sciences in San Francisco, we have found U.S. and Canadian locality

records consistent with White (1982), and we noted five specimens collected in

1931 from Tokyo, Japan.

Although there are no California Department of Food and Agriculture inter¬

ception records for E. mollis, our collection from Oakland is not the first North

American record of this insect west of Texas. There is one specimen labelled

Ernobius mollis in the University of California Essig Museum collected in 1952

and labelled “Slab crate, ex Michigan, Hueneme Calif.” This interception most

likely occurred in southern California at Port Hueneme located 6 km S of Oxnard.

Our experiences show that this species is established in Oakland, California. This

insect may have spread to California through rough-wood packing case timbers

from the ports of Oakland or San Francisco as occurred in South Africa. However,

it could also have entered the state through interstate overland commercial or

residential traffic. It is significant that we found E. mollis contributing to the death

of a living tree in California, because it appears to have caused greater damage

as an introduced insect than it did in its old world habitat (Hickin 1968).

Although we have recovered this insect from a European tree species that has

1993

SEYBOLD & TUPY: ERNOBIUS MOLLIS IN CALIFORNIA

been listed as one of its principal hosts (Gardiner 1953), it is important to note

that E. mollis has again been introduced into a region that has abundant plantings

of P. radiata. Ernobius mollis could act in concert with Ips spp. (unpublished

data) and pitch canker disease (McCain et al. 1987) to contribute to mortality of

P. radiata. Because of its requirement for sapwood with bark attached, it is

doubtful that E. mollis will play a major role as a structural pest in urban Cali¬

fornia. In contrast to the situation in the southern hemisphere, the widespread

urban and native stands of P. radiata in the San Francisco Bay Area are not used

for wood products. However, it could enter structures through firewood and thus

damage rustic finishings. It is important that pest control operators distinguish

between the symptoms of damage by E. mollis and that by the California death-

watch beetle, Hemicoelus gibbicollis (LeConte). The latter species re-infests fin¬

ished wood products, but the former does not. The adults and galleries of these

species could be difficult to distinguish; however, they produce distinctive fecal

pellets. In contrast to the bun-shaped, often dark-colored pellets produced by E.

mollis, H. gibbicollis produces elongated, light-colored pellets.

Record. —CALIFORNIA. ALAMEDA Co.: 2 km SE of Lake Merritt, Greenwood Avenue, Oakland,

22 Feb 1990, S. J. Seybold, Picea abies.

Acknowledgment. — We thank S. Hermanson for permission and assistance with

the collection of E. mollis. Norman Lewis made significant contributions to the

data collection for this project, D. L. Wood critically reviewed the manuscript

and J. E. Lindquist assisted with literature retrieval (all from University of Cal¬

ifornia at Berkeley). We are also grateful to R. E. White (Systematic Entomology

Laboratory, USDA) for identification of E. mollis and J. R. McBride (University

of California at Berkeley) for identification of P. abies. Finally, we thank F.

Andrews, California Department of Food and Agriculture (CDFA) for assisting

us with California interception records for Coleoptera. Specimens of E. mollis

recovered from P. abies were deposited in the University of California Essig

Museum, the U.S. National Museum, the California Academy of Sciences, and

the CDFA Insect Survey.

Literature Cited

Becker, H. 1984. Holzschadigende insekten. Praktische Schadlingsbekampfer, 36: 141-142, 143.

Bevan, D. 1987. Forest insects. A guide to insects feeding on trees in Britain. Forestry Commission

Handbook, 1.

Bletchley, J. D. 1964. Forest-products entomology in the United Kingdom. Ann. Appl. Biol., 53:

184-190.

Bletchley, J. D. 1965. Woodworm problems in buildings, pp. 176, 178. Timber and Plywood Annual.

Bletchley, J. D. 1967. Insect and marine borer damage to timber and woodwork. Recognition,

prevention, and eradication. Ministry of Technology, Forest Products Research Publication.

Casimir, J. M. 1958. Ernobius mollis Linn., an introduced bark beetle. Div. Wood Tech., For.

Comm. New South Wales Tech. Notes, 2: 24-27.

Clarke, A. F. 1932. Insects infesting Pinus radiata in New Zealand. N.Z. J. Sci. Tech., 13: 235-243.

Craighead, F. C. 1950. Insect enemies of eastern forests. USDA Forest Serv. Misc. Pub., 657.

Dominik, J. 1958. Some observations on the biology, prevention, and control of Ernobius mollis L.

(Col. Anobiidae). Sylwan, 3: 61-65.

Gardiner, P. 1953. The morphology and biology of Ernobius mollis L. (Coleoptera: Anobiidae).

Trans. R. Ent. Soc. Lond., 104: 1-24.

Hickin, N. E. 1968. The Insect Factor in Wood Decay. London, Hutchinson.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Hockey, M. J. 1985. Anobiid beetles in timber and buildings in Queensland. Dept. For. Queensland

Advisory Leaflet, 22.

Kelsey, J. M. 1946. Insects attacking milled timber, poles, and posts in New Zealand. N.Z. J. Sci.

Tech., 28: 70-86.

Kemner, N. A. 1915. De ekonomiskt viktiga vedgnagande anobiema. Medd. Cent. Anst. Forsoks.

Jordbr., 108 (Ent. Avd., 9).

McCain, A. H., C. S. Koehler & S. A. Tjosvold. 1987. Pitch canker threatens California pines. Calif.

Agric. 41: 22-23.

Roques, A. 1983. Les insectes ragageurs des cones et graines de coniferes en France. Institut National

De La Recherche Agronomique Publication.

Schmidt, H. 1951. Mikroscopie des bohrmehls holzschadlicher kafer. Handbuch der Mikroskopie

in der Technik, 5: 369-379.

Schmidt, H. 1971. Holzminierende kaferlarven. 2. Nage-, klopf-, Oder Pochkafer (Anobiidae). Holz

als Roh- und Werkstoff, 29: 201-204.

Simeone, J. B. 1962. Survey of wood-feeding Anobiidae in northeastern United States, including a

study of temperature and humidity effects on egg development of Hadrobregmus carinatus

(Say.), pp. 326-335. In Proc. XI Int. Cong. Ent., Vienna (1960), 2.

Tooke, F. G. C. 1946. Beetles attacking seasoned timber in South Africa, Part 2: the bark anobiid

Ernobius mollis Linn, and keys to the common insect pests of timber and to common insect

damage to timber in South Africa. Dept. Agric. For. Entomol. Ser., 6.

Tooke, F. G. C. 1949. Beetles injurious to timber in South Africa: A study of their prevention and

control. Dept. Agric. For. Entomol. Ser., 28.

Trag&rdh, I. 1938. Survey of the wood-destroying insects in public buildings in Sweden. Bull. Ent.

Res., 29: 57-62.

Unger, W. 1986. Was sind Anobien? Holztechnologie, 27: 255-257.

White, R. E. 1982. A catalog of the Coleoptera of America north of Mexico: Family Anobiidae.

USD A Agric. Handbook, 529-70.

Received 2 December 1991; accepted 20 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 41-50, (1993)

HOST PLANT PREFERENCES OF

ACANTHOSCELIDES A UREOLUS (HORN)

(COLEOPTERA: BRUCHIDAE)

Wayne R. Owen

Graduate Group in Ecology, University of California

Davis, California 95616 1

Abstract. —The discrimination oi Acanthoscelides aureolus Horn (Coleoptera: Bruchidae) among

individuals of its host plants, Astragalus kentrophyta var. implexus (Fabaceae), was investigated

using a path analytical model that included seven demographic variables. Seed number proved

to be the plant trait that contributed most to the rate bruchid use among host individuals. Seed

number also exerted an important indirect effect on the correlations between the rate of bruchid

use and the other variables in this analysis.

Key Words. — Insecta, Bruchidae, Acanthoscelides aureolus, Astragalus kentrophyta var. implexus,

path analysis, oviposition preference

Acanthoscelides aureolus Horn (Coleoptera: Bruchidae) is a generalist seed¬

eating bruchid that uses the seeds of host plants across a broad range of taxonomic

affinities (Johnson 1970). At high elevations in the White Mountains of Inyo and

Mono Counties in eastern California, A. aureolus uses the seeds of an alpine

cushion plant, Astragalus kentrophyta var. implexus (Fabaceae) (hereafter referred

to as Aki), to the exclusion of all other hosts (Owen 1991a). A. aureolus is the

only predispersal consumer of Aki seeds at alpine elevations in the White Moun¬

tains (Owen 1991b). The size of the study population of A. aureolus varies greatly

from year to year (Owen 1991b); a commonplace feature among species of seed

eating insects with narrowly defined diets (Janzen 1970, Huffaker et al. 1984).

Patterns of predispersal seed predation have important demographic conse¬

quences for populations of flowering plants. By reducing the number of seeds

released to the environment, seed-eating insects affect the density of propagules

in the dispersal range of each parent plant. In turn, the recruitment of adults into

the host population may be adversely affected by either a reduction in the absolute

number of seeds in the soil or by decreasing the likelihood of propagules reaching

safe sites (Harper 1977).

Because seed predators can have a profound impact on their host species (Janzen

1971, 1981; Louda 1982; Fenner 1985), knowledge of the criteria by which female

insects discriminate among potential hosts would be especially useful in the man¬

agement of rare plant species. Because several species of Astragalus in North

America experience significant fecundity losses due to seed predation (e.g., Al-

verson 1985, Smithman 1988, Wright 1988, Lesica & Elliott 1989, Rittenhouse

1990), an analysis of the A. aureolus/ Aki system could potentially serve as a

robust model for the analysis of other bruchid/legume systems.

Seed predation patterns may be the result of the dispersal pattern of the insect

or may be due to choices made by ovipositing females. Discrimination among

1 Mailing address: Boise National Forest, 1750 Front Street, Boise, Idaho 83702.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

potential oviposition sites may be influenced by a variety of host plant attributes

including fruit color (Riedl & Hislop 1985, Owens & Prokopy 1986), fruit size

(Messina 1990), leaf size (Whitham 1978, 1980), plant or shoot size (Everly 1959,

Rausher 1983, Fritz & Nobel 1989, Cipollini & Stiles 1991), and flowering phe¬

nology (Feeny 1976, Pettersson 1991).

I investigated the rates of seed predation by A. aureolus on a group of Aki plants

in the White Mountains. Seed predation at this site varies significantly and non-

randomly among individuals (0-100%, Owen 1991b) suggesting that females are

discriminating among hosts (Rausher 1983). This discrimination is probably not

due to differences in phenology among host individuals because Aki flowers and

fruits continuously throughout the short growing season in the White Mountains

(Owen 199 lb). Furthermore, because the chemical constitution of a species’ seeds

tends to be very uniform within populations (Janzen 1978), it is unlikely that

bruchids would discriminate among host plants on the basis of seed quality. Here,

I test the importance of physical/reproductive characteristics among Aki individ¬

uals to the discrimination by ovipositing A. aureolus females. This particular

bruchid /Astragalus interaction is interesting because of the unusual and severe

nature of the environment that these species share. This paper presents an analysis

of the relationship between the level of bruchid infestation and physical/repro¬

ductive attributes of Aki over a two year period.

Materials and Methods

I randomly selected a group of 80 Aki plants on the alpine dolomite barrens

of Sheep Mountain in the White Mountains, Mono County, California (elevation

3620 m) for study. Little is known about the ways in which species of Acanthosceli-

des select oviposition sites. Cipollini & Stiles (1991) report thatri. obtectus females

select among Phaseolus flowers on the basis of their not having been previously

visited by an ovipositing female, and that they do not discriminate among ovi¬

position sites on the basis of expected seed size. Green & Palmbald (1975) report

that Acanthoscelides fraterculus selects among potential Astragalus species for

oviposition on the basis of their flowering phenology, and physical and chemical

differences between the fruits of potential host species. In light of a general lack

of a priori expectations as to which host plant traits might be most important to

a female bruchid in her search for oviposition sites, I monitored seven demo¬

graphic characteristics (Table 1) that could reasonably be assumed to be the basis

of discrimination among host plants by ovipositing female A. aureolus throughout

the 1989 and 1990 growing seasons. Plant size was measured as the area (mm 2 )

covered by individual cushions at the beginning of each growing season. At the

end of each growing season all fruits and seeds produced on each plant were

collected and individually weighed. Seed dispersal occurs very late in the growing

season, is passive and very limited in distance (Owen 1991b), so I am confident

that I was able to harvest every seed produced by every plant. The vigor of each

plant was estimated as its relative annual growth (i.e., the total growth in area

during a season divided by the initial plant size). Each seed produced by the 80

Aki plants was individually inspected for the evidence of predation. Because A.

aureolus larvae leave a characteristic scar on seeds, their presence or absence can

be unequivocally determined by visual inspection. Furthermore, microscopic in¬

spection of several hundred Aki flowers showed that A. aureolus eggs and larvae

1993

OWEN: ACANTHOSCELIDES AUREOLUS HOST PLANTS

Table 1. Comparison of mean trait values across in the two years of the experiment.

1989

1990

Mean

CV ; '

Mean

t b

Plant size

(mm square)

6580.04

57.28

7460.22

54.71

-4.94

0.01

Fruit number

24.53

118.50

29.27

110.45

-0.98

Seed number

28.60

117.40

33.06

109.82

-0.91

Fruit weight

(milligrams)

1.54

23.50

1.46

24.40

2.03

0.05

Seed weight

(milligrams)

1.78

17.99

1.68

23.63

2.26

0.05

Seed/fruit

0.98

57.00

1.04

40.95

-0.29

Vigor

(growth/size)

0.23

146.07

0.19

179.13

1.18

a The coefficients of variation (CV) are given to indicate the relative variability of each character.

b Differences in the means tested with two-tailed paired Student’s t.

are not present in abortive flowers (Owen 1991b). I am, therefore, confident that

I have accounted for all oviposition events made by A. aureolus on the 80 Aid

plants.

The effect of each plant trait on the level of seed predation was investigated

with a path analytical model (Dewey & Lu 1959, Sokal & Rohlf 1981). A path

analysis allows the simultaneous consideration of several intercorrelated variables

in a linear regression frame work. In the path analysis, a cause and effect rela¬

tionship between the predictor variables (the seven demographic characteristics

presented in Table 1) and the criterion variable (rate of bruchid attack) is assumed.

The standard partial correlation coefficients from the multiple linear regression

are presented as path coefficients, and as such represent the direct influence of

those variables on the criterion variable. All unknown (residual) factors are com¬

bined into a coefficient of nondetermination ( U ), which reflects the fraction of the

model variance unaccounted for by the predictors. Because the path analysis

requires data to conform to the distributional assumptions of linear regressions,

the appropriate transformations have been made to improve the normality of

some variables. Separate paths are constructed for the 1989 and 1990 data.

The rate at which A. aureolus uses Astragalus seeds is expressed as the ranked

percentage (Conover & Iman 1981) of seeds per plant used by A. aureolus. Ranked

rates of seed use best serve the objective of the model in that ovipositing females

may not always choose the “best” host plant but must rank the quality of and

choose among the host plants that they encounter (Rausher 1983).

Because many of the predictor variables are intercorrelated (Table 2), each may

exert a telling influence on the correlation between other predictors and the cri¬

terion variable. The potential indirect effects of variables can be investigated by

using the normal equations originally used to determine the path coefficients. For

example, for the first variable in this analysis,

r iY = P\Y + ^12-^27 f r i3^3Y T r \ 4 P 4 Y + r \5^ > 5Y^~ r \6^6Y ^ll^lY-

In this expression, r is the coefficient of correlation between variables i and j, Y

is the criterion variable, and P represents standard regression coefficients. There-

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Table 2. Correlations among plant traits used in the path analysis. Values above the diagonal are

based on 1989 data, those below the diagonal are for 1990 data.

Plant size

Fruit

number

Seed number

Fruit

weight

Seed

weight

Seeds/fruit

Vigor

Plant size

0.403** a

0.532**

0.015

0.025

-0.006

-0.255*

Fruit number

0.621**

—

0.509**

0.071

0.201

-0.341**

0.117

Seed number

0.585**

0.966**

—

0.035

0.177

0.253*

-0.017

Fruit weight

-0.053

0.054

0.086

—

0.368**

-0.010

0.155

Seed weight

0.035

0.102

0.076

0.284*

—

-0.070

0.255*

Seeds/fruit

-0.036

0.007

0.209

0.260*

0.100

—

0.230*

Vigor

-0.130

-0.069

-0.039

0.043

0.052

0.137

—

a Significance levels: * = P < 0.05; ** = P < 0.01.

fore, r lY is the correlation between predictor variable 1 and the criterion variable

and P lY represents the direct effect (path coefficient) of predictor variable 1 on the

criterion variable Y. The indirect effects are represented by the products In

the example above, a small correlation between predictor variables 1 and j will

exert a minimal influence on the overall correlation between predictor 1 and the

criterion variable by decreasing the contribution of r ijPjY to r iy . Conversely, when

r Xj is large, r Xj P jY exerts a nontrivial effect on r ] Y . An analysis of the indirect effects

is crucial to gaining a complete understanding of the relationship between the

predictor variables and the criterion variable.

Results and Discussion

Mean values and coefficients of variations for the seven plant traits used in this

analysis are presented in Table 1. Paired Student’s Mests were used to discern

whether trait values differed significantly between 1989 and 1990. Not surpris¬

ingly, plant size was significantly greater in 1990 than in 1989 (a reflection of

annual growth). There were significant differences in the mean (within individual)

weight of fruits and seeds between years (Table 1). Although 1989 reproductive

products were heavier, the difference between years is no more than 0.1 mg (6%

change). Although the coefficients of variation for mean seed size are small (Table

1), within-individual seed weights vary by as much as a factor of eight (Owen

1991b). This pattern of greater variation within, rather than among, individuals

for seed size variation would make discrimination very difficult among host plants

by the female bruchid on the basis of seed size. The number of fruits and seeds

produced by individuals did not differ significantly between years (Table 1). In

contrast, the number of fruits and seeds produced varied widely among test in¬

dividuals. Individual plants produced 0-165 and 0-187 fruits, and 0-179 and 0-

150 seeds in 1989 and 1990, respectively. Vigor, the relative growth rate of

individuals, did not differ significantly between years, but varied widely among

individuals. In both years, some individuals decreased in size by just over 50%,

but others increased by approximately 70%. Finally, the number of seeds per fruit

was consistent between years and among individuals.

The correlations among the demographic variables used in the path analysis

are presented in Table 2. There are several significant correlations, most notable

are the associations between fruit and seed number and plant size. The correlation

between fruit and seed weight is likewise consistent across years. Other correlations

1993

OWEN: ACANTHOSCELIDES AUREOLUS HOST PLANTS

1989

Oviposition

Preference

1990

Oviposition

Preference

Figure 1. Path coefficients (direct effects) for predictor variables on the ranked percentage of seeds

consumed by bruchid larvae in 1989 and 1990. Cross correlations among predictor variables are

presented in Table 2. U represents the coefficient of nondetermination, a residual factor for the path

model.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

occur only in either 1989 or 1990. Such transient correlations are difficult to

interpret alone and may, in fact, be spurious.

The results of the path analyses for 1989 and 1990 are presented in Fig. 1.

Because there is no way of establishing statistical significance for path coefficients

(but see Mitchell 1991), their value must be judged in accordance with their

individual magnitudes. The large residual factors ( U) indicates that most of the

variation in bruchid infestation rate among plants was not accounted for by the

path analysis. Although the paths for seed number consistently have the greatest

coefficients, there are some potentially important inconsistencies in the results for

the other predictor variables. The importance of fruit weight changes by an order

of magnitude between years. Fruit weight becomes less important to the model

in 1990, when fruit weight is significantly less compared to 1989. This correlation

might be due to heavier fruits, with thicker walls, being more difficult to oviposit

in than are lighter fruits with correspondingly thinner walls. The direct effect of

fruit number, seeds per fruit, and vigor changes sign between years, indicating

that they are poor predictors of host quality. The advantage of monitoring bruchid

selection of host plants for more than one year is evidenced in the path coefficient

for seeds per fruit (Fig. 1). In 1989 that direct effect was trivial (0.078), but in

1990 it was second in magnitude only to seed number (—0.393). Seed weight was

consistently important in host plant selection in both years. Plant size, although

consistently negatively associated with host plant preference, varied greatly in

magnitude between years.

The effects of the predictor variables, through their influence on one another,

are presented in Table 3. In Table 3, the correlation coefficients between individual

predictors and bruchid infestation rates ( r iY ) are presented as the sums of the path

coefficients ( P iY ) and the indirect effects (r^y). These decompositions show that

most variables contribute very little to the correlations between predictors and

criterion variables and consequentially do not substantially affect individual cor¬

relations among predictors and bruchid use ( r iY ). In contrast, the indirect effect

of seed number ( r i3 P 3Y ) consistently exerts an important influence on the rela¬

tionship between predictors and the ranked rate of A. aureolus infestation.

The combined results of the path analysis and the decomposition of the normal

equations strongly supports seed number as the most important trait of Aki to A.

aureolus females when making oviposition choices. However, at the time of ovi-

position the size of seed crop of each plant is ambiguous; this suggests that either

the bruchids are cueing on some plant attribute, which is correlated with seed

production, that is not considered in this analysis, or that they are somehow using

the history of seed production for a given plant as an indicator of its future

productivity. Table 4 provides the results of simple linear regressions for the

values of each predictor variable in 1990 on the 1989 trait values. Plant size is

the trait that is most consistent across years (r 2 = 0.877). However, the density

of seeds produced by individual plants (seeds produced/plant size) is inconsistent

across years (t = 0.463, P = 0.645), indicating that plant size is a poor predictor

of seed production. Seed number is the next most consistent plant characteristic

in Aki ( r 2 = 0.407). Additionally, seed production by Aki is exceptionally stable

in the face of environmental fluctuations. In an experiment using 189 Aki plants,

no changes in fecundity were detected in response to supplemental watering,

herbivore abatement, fertilization, or the removal of competitors (Owen 1991b).

1993

OWEN: ACANTHOSCELIDES AUREOLUS HOST PLANTS

Table 3. Indirect effects on the correlation between individual predictor variables and bruchid

infestation rate.

Value

Category/effect Variable 1989 1990

Plant Size vs. Bruchid Infest. Rate

Direct effect

Indirect effect of fruit number

Indirect effect of seed number

Indirect effect of fruit weight

Indirect effect of seed weight

Indirect effect of seeds/fruit

Indirect effect of vigor

Seed Number vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

Indirect effect of fruit number

Indirect effect of fruit weight

Indirect effect of seed weight

Indirect effect of seeds/fruit

Indirect effect of vigor

Seed Weight vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

Indirect effect of fruit number

Indirect effect of seed number

Indirect effect of fruit weight

Indirect effect of seeds/fruit

Indirect effect of vigor

Vigor vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

Indirect effect of fruit number

Indirect effect of seed number

Indirect effect of fruit weight

Indirect effect of seed weight

Indirect effect of vigor

Fruit Number vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

Indirect effect of seed number

Indirect effect of fruit weight

Indirect effect of seed weight

Indirect effect of seeds/fruit

Indirect effect of vigor

Fruit Weight vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

Indirect effect of fruit number

Indirect effect of seed number

Indirect effect of seed weight

Indirect effect of seeds/fruit

Indirect effect of vigor

Seeds/Fruit vs. Bruchid Infest. Rate

Direct effect

Indirect effect of plant size

0.112

-0.032

PXY

-0.062

-0.232

r I2P2Y

0.042

-0.065

r^PiY

0.118

0.267

r \4P4Y

-0.003

0.001

r l5 PsY

0.005

0.004

r 16 P 6Y

-0.001

0.014

r i yPiY

0.012

-0.021

0.291

0.139

PiY

0.222

0.457

r 3\P\Y

-0.033

-0.136

^32-^2 y

0.053

-0.101

r 24P4Y

-0.007

0.002

^sPsy

0.036

0.009

r 36 P 6 Y

0.020

-0.082

7*37 PlY

0.001

-0.006

0.165

0.097

PSY

0.201

0.119

r i\P\Y

-0.002

-0.008

^52^2 Y

0.021

-0.011

^53-P3 Y

0.039

0.035

r :54P4Y

-0.077

-0.007

r 56 P 6 Y

-0.006

-0.040

r^PiY

-0.012

0.009

0.014

0.135

PlY

-0.047

0.164

r i\P\Y

0.016

0.030

ri 2 P2Y

0.012

0.007

r n P iY

-0.004

-0.018

r 14P5Y

-0.033

-0.001

r^PsY

0.051

0.006

r IbPbY

0.018

-0.054

0.186

0.190

P 2Y

0.104

-0.105

r :21 P 1 Y

-0.025

-0.144

r 23P3Y

0.113

0.442

-0.015

0.001

^25 P sy

0.041

0.012

r 2bPbY

-0.027

-0.003

r 2lPlY

-0.006

-0.011

-0.130

-0.039

1 4y

-0.210

-0.233

^4\P\ Y

-0.001

0.012

r 42P2Y

-0.007

-0.006

f43P 3Y

0.008

0.039

r 4S P5Y

0.074

0.034

r 46 P bY

-0.001

-0.102

^ 41 PlY

-0.007

0.007

0.076

-0.262

PbY

0.078

-0.393

feiP iy

<0.001

0.008

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 3. Continued.

Category/effect

Variable

Value

1989

1990

Indirect effect of fruit number

r 6lP2 Y

-0.036

-0.001

Indirect effect of seed number

r 63-G y

0.056

0.096

Indirect effect of fruit weight

f 64 T 4 y

0.002

-0.006

Indirect effect of seed weight

r 6 5 Psy

-0.014

0.012

Indirect effect of vigor

r 67 Ay

-0.011

0.022

Fruit and seed weight are likewise consistent among Aki individuals across years

(Table 4), although there are significant between-year differences in population

wide mean values of these traits (Table 1). Further complicating the reliability of

fruit and seed weight as indicators of host quality are the generally small corre¬

lations between these traits and seed number (Tables 2 and 4). Finally, although

the path coefficients for fruit and seed weight are the same magnitude as the path

for seed number in 1989 (Fig. 1), their relative importance declines dramatically

in 1990 suggesting instability in those traits that would not favor their use as a

guide to host plant quality.

It is not surprising that A. aureolus would discriminate among potential hosts

based on consistently high rates of fecundity. There should, however, be a cost

incurred by Aki individuals in being consistently selected as an oviposition site

for A. aureolus. I suggest that plants that are subject to chronic seed predation

could reduce predation levels by increasing their interannual variance in seed

production. This is commonly accomplished by the occasional production of large

numbers of offspring, and producing very few offspring in intervening years (i.e.,

masting, see Janzen 1969). Although common among tree species, masting does

not occur among herbaceous perennials in general (Fenner 1985), or in Aki spe¬

cifically (Owen 1991b). The consequence of consistent seed production is chronic

and, in some cases, heavy reductions in fecundity. For Aki, regressions of the

number of seeds that escape predation on the total number produced in both 1989

and 1990 have slopes significantly less than, but very near, unity (Table 5). Con¬

sequently, greater seed production does not lead to proportionally greater survi¬

vorship among the annual progeny cohort of each plant. This pattern may be

Table 4. Results of simple linear regression analyses comparing predictor trait values between

1989 and 1990.

Predictor

r 2

Plant size 3

550.05

0.0001

0.877

Fruit number

9.10

0.0035

0.107

Seed number

51.55

0.0001

0.407

Fruit weight

36.36

0.0001

0.339

Seed weight

22.26

0.0001

0.247

Seed/fruit

0.39

0.5343

0.007

Vigor

4.16

0.0448

0.052

a Data are transformed as required to impose normality.

1993

OWEN: ACANTHOSCELIDES AUREOLUS HOST PLANTS

Table 5. Slopes and confidence intervals for regressions of the number of seeds produced that

escaped predation on the total number of seeds produced.

Year

Slope

99% lower

99% upper

1989

0.965

0.934

0.996

1990

0.823

0.766

0.881

responsible for the overall low fecundity observed among Aki plants. Although

all plants produce many more flowers than seeds (i.e., many flowers are regularly

aborted, Owen [1991b]), few plants produce many seeds. The maximum seed

crops among Aki plants in this analysis were 179 and 150, in 1989 and 1990,

respectively. Mean seed crops were much lower, however, at 28.6 in 1989 and

33 in 1990 (Table 1).

It is yet to be shown that the interaction illustrated here is common to other

bruchid /Astragalus systems. It is important to note that the results reported here

were recorded in an extreme environment and the ecology of these species may

differ in fundamental ways in more amiable habitats. Because Aki and A aureolus

occur together at lower elevations (Owen 1991b), a broader investigation could

be accomplished and would add to a greater understanding of the biology of both

species.

Acknowledgment

I thank T.-L. Ashman, E. Nagy, and C. D. Johnson for their critical review of

this manuscript. Early discussions about the evolution of reduced fertility with

T.-L. Ashman and D. Wiens were especially useful and appreciated. Field research

for this project was supported by the White Mountain Research Station, Uni¬

versity of California, Los Angeles.

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and Wildlife Service, Boise, Idaho.

Cipollini, M. L. & E. W. Stiles. 1991. Seed predation by the bean weevil Acanthoscelides obtectus

on Phaseolus species: consequences for seed size, early growth and reproduction. Oikos, 60:

205-214.

Conover, W. J. & R. L. Iman. 1981. Rank transformations as a bridge between parametric and

nonparametric statistics. Am. Stat., 35: 124-129.

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Everly, R. R. 1959. Influence of height and stage of development of dent com on oviposition by

European Com Borer moths. Ann. Entomol. Soc. Am., 52: 272-279.

Fenner, M. 1985. Seed Ecology. Chapman & Hall, New York.

Fenny, P. 1976. Plant apparency and chemical defense. Rec. Adv. Phytochem., 10: 1-40.

Fritz, R. S. & J. Nobel. 1989. Plant resistance, plant traits, and host plant choice of the leaf-folding

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Green, T. W. & I. G. Palmbald. 1975. Effects of insect seed predators on Astragalus cibarius and

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Harper, J. L. 1977. Population Biology of Plants. Academic Press, New York.

Huffaker, C. B., A. A. Berryman & J. E. Laing. 1984. Natural control of insect populations, pp. 359—

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THE PAN-PACIFIC ENTOMOLOGIST

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Janzen, D. H. 1969. Seed-eaters versus seed size, number, toxicity, and dispersal. Evolution, 23:

1-27.

Janzen, D. H. 1970. Herbivores and the number of tree species in tropical forests. Am. Nat., 104:

501-528.

Janzen, D. H. 1971. Seed predation by animals. Ann. Rev. Ecol. Syst., 2: 465-492.

Janzen, D. H. 1978. The ecology and evolutionary biology of seed chemistry as relates to seed

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Ph.D. Dissertation, University of California, Davis.

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Received 6 January 1992; accepted 20 August 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 51-56, (1993)

LOW ALLOZYME VARIATION IN

FORMOSAN SUBTERRANEAN TERMITE

(ISOPTERA: RHINOTERMITIDAE) COLONIES IN HAWAII

K. L. Strong 1 and J. K. Grace 2

Department of Entomology, University of Hawaii,

Honolulu, Hawaii 96822-2271

Abstract. —Cellulose acetate gel electrophoresis was used to assess allozyme variation among

Hawaiian populations of Coptotermes formosanus Shiraki. Twenty-nine protein loci were re¬

solved in an initial survey. Eight of these proved to be reliable, and 13 termite colonies from

the islands of Oahu and Maui were surveyed for these loci. Individual workers (pseudergates)

were monomorphic for all loci across all colonies, although preliminary results from starch gel

electrophoresis suggest that a very low level of polymorphism is present at one locus. This finding

is consistent with previous electrophoretic studies of C. formosanus populations, which have

found little genetic variation. Low allozyme variation may be characteristic of this species, or

Hawaiian C. formosanus colonies may be derived from a single introduction or from multiple

introductions of very closely related individuals.

Key Words.— Insecta, termite genetics, cellulose acetate gel electrophoresis

The Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera:

Rhinotermitidae) is native to China (Kistner 1985) but has been distributed ex¬

tensively by man through the tropical and subtropical regions of the world. The

range of this serious economic pest now includes South Africa, Sri Lanka, Japan,

Taiwan, Guam, the Midway islands, the Hawaiian islands and the United States

mainland (Su & Tamashiro 1987). Coptotermes formosanus was collected in Ho¬

nolulu, Hawaii in 1907 and recorded as established in 1913 (Zimmerman 1948);

however, it may have been present as early as 1869 (Tamashiro et al. 1987). Since

then, it has spread throughout the islands of Oahu and Kauai, with distributions

restricted to certain seaports or areas immediately surrounding seaports on the

islands of Hawaii, Maui, Molokai and Lanai (Tamashiro et al. 1987). This termite

has spread slowly through the state and has been distributed mainly via the actions

of man (Higa & Tamashiro 1983, Tamashiro et al. 1987). However, it has become

the most important economic pest in the Hawaiian islands (Tamashiro et al.

1987). Populations of mature colonies of C. formosanus number in the millions

of individuals (Su et al. 1984).

Demographics, foraging dynamics, and biochemical characteristics of several

C. formosanus colonies on Oahu are monitored regularly using a trapping tech¬

nique (Tamashiro et al. 1973). Aggressive interactions have been observed be¬

tween members of some, but not all, of these termite colonies (Su & Haverty

1991). Such agonistic displays may represent interactions between genetically

differentiated colonies (Su & Scheffrahn 1988). Allozyme electrophoresis has fre¬

quently been used to obtain estimates of insect genetic relatedness (Berlocher

1 Current address: Division of Botany and Zoology, Australian National University, GPO Box 4,

Canberra, ACT 2601, Australia.

2 Author for reprint requests.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Figure 1. Locations of Coptotermes formosanus colonies sampled from the island of Oahu, Hawaii.

An additional colony was sampled from Lahaina, Maui (not shown). 1, Poamoho Experiment Station

field shed; 2, Poamoho Experiment Station (founded from laboratory stock); 3, Waipio peninsula;

4, Pearl Harbor; 5, Manana warehouses; 6, University of Hawaii at Manoa campus (six colonies); 7,

Kaneohe residential yard.

1984). Similarly, this technique has been used to investigate the origin of intro¬

ductions of C. formosanus to the United States mainland and the possibility of

cryptic species within the range of C. formosanus in the United States (Korman

& Pashley 1991).

Valuable information on the population structure and size of rhinotermitid

colonies has been collected in previous studies of allozyme variation (Clement

1981, Reilly 1988). Our electrophoretic investigation was initiated to find allo¬

zyme markers useful in distinguishing among different C. formosanus colonies.

Such markers could be used to determine the number and sources of termite

introductions to Hawaii, and possibly to trace the spread of this termite throughout

the state. We also wished to determine if the agonistic encounters between C.

formosanus colonies recorded, by Su & Haverty (1991), were correlated with

allozyme differences.

Materials and Methods

Termite collections. — Formosan subterranean termite workers (pseudergates, or

undifferentiated individuals older than the third instar) were collected from 13

locations, representing 13 different colonies, on the Hawaiian islands of Oahu

and Maui (Fig. 1). These included the colonies used by Su & Haverty (1991) in

their study of intercolony agonistic interactions (N.-Y. Su, personal communi-

1993

STRONG & GRACE: TERMITE ALLOZYME VARIATION

Table 1. Presumptive enzyme loci and buffer systems used in electrophoretic survey of Hawaiian

Coptotermes formosanus.

Locus

Abbrev.

E.C. number

Buffer

system”

No. of

loci

Aconitase 11

Aeon

4.2.1.3

Glucose phosphate isomerase 3

Gpi

5.3.1.9

B-hydroxybutyrate dehydrogenase

Hbdh

1.1.1.30

Aldehyde oxidase

1.2.3.1

Adenylate kinase 3

2.7.4.3

Alcohol dehydrogenase

Adh

1.1.1.1

Amino aspartate transferase

Aat

2.6.1.1

Fructose 1,6-diphosphate dehydrogenase

Fdp

3.1.3.11

Hexokinase

2.7.1.1

Isocitrate dehydrogenase

Idh

1.1.1.42

Phosphoglucomutase

Pgm

2.7.5.1

Glucose 6-phosphate dehydrogenase

G6pd

1.1.1.49

Malic enzyme

1.1.1.40

Malate dehydrogenase 3

Mdh

1.1.1.37

6-phosphogluconate dehydrogenase

6Pgd

1.1.1.44

Fumerase hydratase

4.2.1.2

Esterase 3

Est

3.1.1.1

Mannose 6-phosphate isomerase

Mpi

5.3.1.8

Glyceraldehyde 3-phosphate dehydrogenase

Gapd

1.2.1.12

3 Reliable loci chosen for comparison among all termite colonies.

b Buffer systems: A, 100 mM tris maleate (pH 7.8); B, 100 mM tris citrate (pH 8.2); C, 100 mM

phosphate (pH 7.0); D, 100 mM tris borate EDTA (pH 8.9).

cation). Six of the colonies are located on the Manoa campus of the University

of Hawaii, and are monitored monthly using the trapping technique described by

Tamashiro et al. (1973). Two other Oahu colonies that are regularly monitored

are located at the Poamoho Experiment Station: one of these was originally found¬

ed from unknown laboratory stock in 1979 (M. Tamashiro, personal communi¬

cation), but the other is adventitious in the vicinity of a field shed. The other two

Oahu colonies subject to monitoring are located (1) in a sugarcane field on the

Waipio peninsula, and (2) in a residential yard in Kaneohe. Two other collections

were made on Oahu from infested wood found on the ground within the U.S.

Navy’s Pearl Harbor and Manana warehouse facilities. A single collection from

fence posts in Lahaina, Maui, represents a recent introduction to that part of the

island. Samples from each of these 13 colony sources were maintained alive in

the laboratory, or snap frozen in liquid nitrogen, until prepared for electrophoresis.

Electrophoresis.— Cellulose acetate (Cellogel, Chemetron, Milan, Italy) hori¬

zontal gel electrophoresis was used to resolve the products of 29 presumptive

enzyme loci (Table 1). This method is simple and efficient with small insects,

because less than 1 pi of sample need be applied to the gel to achieve maximal

stain intensity. The buffer systems and staining procedures used were those of

Richardson et al. (1986). As noted in Table 1, buffer systems were: 100 mM tris

maleate (pH 7.8) [A], 100 mM tris citrate (pH 8.2) [B], 100 mM phosphate (pH

7.0) [C], and 100 mM tris borate EDTA (pH 8.9) [D]. Individual termites were

ground in Eppendorf centrifuge tubes using a fitted pestle and 0.1 ml of 100 mM

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

tris HC1 (pH 8.0) buffer. Approximately 1 ^1 of each ground sample was applied

to pre-made loading slots with a draughtsman’s pen (Richardson et al. 1986).

In an initial screening, 6-21 individuals from each of the University of Hawaii

C. formosanus colonies were assayed for each presumptive enzyme locus. Eight

reliable loci were identified for comparison with the other termite colonies. All

13 colonies were then compared for these eight loci, with 4-26 individuals from

each colony examined. The smaller sample sizes came from the colonies found

at Pearl Harbor, Manana (Oahu), and Lahaina (Maui), where fewer individuals

were collected.

Results and Discussion

Using cellulose acetate gel electrophoresis, no polymorphisms were found for

any of the 29 loci (Table 1) in the 13 Hawaiian C. formosanus colonies surveyed,

and thus no allozyme variation was identified within or between these colonies.

In their survey of geographically disparate populations of C. formosanus from the

mainland United States and Hawaii, Korman & Pashley (1991) reported that only

3 of 18 loci (16.7%) were polymorphic. They concluded that C. formosanus was

depauperate of genetic variation, especially when compared to the approximate

40% polymorphic loci for the class Insecta as a whole (Nevo 1978). We were

unable to reliably score two of the esterase loci that Korman & Pashley (1991)

found to be polymorphic, and our methods did not elucidate the polymorphism

reported by these authors for glucose phosphate isomerase (Gpi, Table 1). How¬

ever, our preliminary results (unpublished data) with horizontal starch gel elec¬

trophoresis, using the methods of Korman & Pashley (1991), have subsequently

confirmed that Gpi is polymorphic in Hawaiian C. formosanus, although no

additional polymorphisms have been resolved.

Several studies have reported greater allozyme variation in other termite species.

Korman et al. (1991) distinguished among Zootermopsis angusticollis (Hagen),

Z. laticeps (Banks), and Z. nevadensis (Hagen) (Termopsidae) on the basis of 11

polymorphic loci. Clement (1981) found European Reticulitermes spp. (Rhino-

termitidae) to have a high proportion of polymorphic loci (52%) and he used fixed

electromorph differences to delineate different species. In contrast, allozyme elec¬

trophoresis by Reilly (1987) revealed only four polymorphic loci in Reticulitermes

flavipes (Kollar) colonies from the southern United States, suggesting that these

colonies were inbred and genetically isolated.

Cuticular hydrocarbon profiles have been used to separate colonies of C. for¬

mosanus from four geographically distinct areas (Florida, Hawaii, and two sites

in Louisiana) (Haverty et al. 1990). In so much as cuticular hydrocarbon profiles

reflect genetic phenomena, these results indicate that genetic differences may exist

between C. formosanus colonies from disparate regions. However, Su & Haverty

(1991) did not find any correlation between cuticular hydrocarbon profiles and

intercolony agonistic behavior, which could also reflect genetic differences. The

Hawaiian colonies studied by Su & Haverty (1991) were included in our allozyme

survey and did not differ at allozyme loci. Thus, the genetic basis of these allozyme

loci and of cuticular hydrocarbons appears to be unrelated to that of intercolony

agonistic behavior.

Although we do not know what degree of allozyme variation is present in C.

formosanus in China, where this species is indigenous (Kistner 1985), Hawaiian

1993

STRONG & GRACE: TERMITE ALLOZYME VARIATION

populations may have lost variation either as a result of founder events and

subsequent genetic drift, or of inbreeding. Natural movement of termites to nearby

locations may take years, as demonstrated by an established colony on Maui that

moved only a few kilometers in over 20 years (Tamashiro et al. 1987). Thus, the

spread of C. formosanus throughout Hawaii was certainly aided by man via

transport of partial colonies in infested wood. Inbreeding in rhinotermitids is

facilitated by the common event of colony fission, or formation of new colonies

by development and mating of supplementary reproductives within a large colony

and subsequent “budding off’ of these individuals and their offspring to form an

adjacent independent colony (Weesner 1956). Asynchronous swarming of nearby

termite colonies could also result in new colony formation by paired siblings, and

has been suggested as a mechanism for generating inbreeding in R. flavipes, where

winged alates captured before dispersal from different colonies are often at different

stages of development (Reilly 1987).

A wider geographic sampling of C. formosanus colonies or alternative electro¬

phoretic techniques may yield greater allozyme variation. However, the evidence

to date from our study and that of Korman & Pashley (1991) suggests that lack

of variation may be characteristic of this species and reflect an overall genetic

homogeneity. Alternative, and currently equally acceptable, hypotheses are that

C. formosanus colonies in Hawaii are derived from a single introduction, or from

multiple introductions of very closely related individuals, possibly from the same

geographic locale.

Acknowledgment

We are grateful to R. T. Yamamoto for help with field collections; J. H. Lee

for laboratory assistance; S. H. Saul, H. G. de Couet and K. Kaneshiro for pro¬

viding equipment and advice; V. P. Jones for help in producing the figure; S. H.

Saul, B. E. Tabashnik and M. Tamashiro for helpful comments on an earlier draft

of the manuscript; and A. K. Korman for recipes, advice and encouragement.

Funding was provided by USDA-ARS Specific Cooperative Agreement 58-6615-

9-012. This is Journal Series No. 3741 of the Hawaii Institute of Tropical Agri¬

culture and Human Resources.

Literature Cited

Berlocher, S. H. 1984. Insect molecular systematics. Annu. Rev. Entomol., 29: 403-433.

Clement, J.-L. 1981. Enzymatic polymorphism in the European populations of various Reticulitermes

species (Isoptera). pp. 49-61. In Howse, P. E. & J.-L. Clement (eds.). Biosystematics of social

insects. Systematics Assoc., Spec. Vol. 19. Academic Press, London.

Haverty, M. I., L. J. Nelson & M. Page. 1990. Cuticular hydrocarbons of four populations of

Coptotermes formosanus Shiraki in the United States. J. Chem. Ecol., 16: 1635-1647.

Higa, S. Y. & M. Tamashiro. 1983. Swarming of the Formosan subterranean termite, C. formosanus

Shiraki in Hawaii (Isoptera: Rhinotermitidae). Proc. Hawaiian Entomol. Soc., 24: 233-238.

Kistner, D. H. 1985. A new genus and species of termitophilous Aleocharinae from mainland China

associated with Coptotermes formosanus and its zoogeographical significance (Coleoptera:

Staphylinidae). Sociobiology, 10: 93-104.

Korman, A. K. & D. P. Pashley. 1991. Genetic comparisons among U.S. populations of Formosan

subterranean termites. Sociobiology, 19: 41-50.

Korman, A. K., D. P. Pashley, M. I. Haverty & J. P. La Fage. 1991. Allozymic relationships among

cuticular hydrocarbon phenotypes of Zootermopsis species (Isoptera: Termopsidae). Ann. En¬

tomol. Soc. Am., 84: 1-9.

THE PAN-PACIFIC ENTOMOLOGIST

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Nevo, E. 1978. Genetic variation in natural populations: patterns and theory. Theoret. Popul. Biol.,

13: 121-177.

Reilly, L. M. 1987. Measurements of inbreeding and average relatedness in a termite population.

Am. Naturalist, 130: 339-349.

Richardson, B. J., P. R. Baverstock & M. Adams. 1986. Allozyme electrophoresis: a handbook for

animal systematics and population studies. Academic Press, New York.

Su, N.-Y. & M. I. Haverty. 1991. Agonistic behavior among colonies of the Formosan subterranean

termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), from Florida and Hawaii:

lack of correlation with cuticular hydrocarbon composition. J. Insect Behav., 4: 115-128.

Su, N.-Y. & R. H. Scheffrahn. 1988. Foraging population and territory of the Formosan subterranean

termite (Isoptera: Rhinotermitidae) in an urban environment. Sociobiology, 14: 353-359.

Su, N.-Y. & M. Tamashiro. 1987. An overview of the Formosan subterranean termite (Isoptera:

Rhinotermitidae) in the world, pp. 3-15. In Tamashiro, M. & N.-Y. Su (eds.). Biology and

control of the Formosan Subterranean termite. Univ. of Hawaii, Hawaii Inst, of Tropical Agric.

and Human Resources, Res. Ext. Ser. 83.

Su. N.-Y., M. Tamashiro, J. R. Yates & M. I. Haverty. 1984. Foraging behavior of the Formosan

subterranean termite (Isoptera: Rhinotermitidae). Environ. Entomol., 13: 1466-1470.

Tamashiro, M., J. K. Fuji & P. Y. Lai. 1973. A simple method to observe, trap and prepare large

numbers of subterranean termites for laboratory and field experiments. Environ. Entomol., 2:

721-722.

Tamashiro, M., J. R. Yates & R. H. Ebesu. 1987. The Formosan subterranean termite in Hawaii:

problems and control, pp. 15-22. In Tamashiro, M. & N.-Y. Su (eds.). Biology and control of

the Formosan Subterranean termite. Univ. of Hawaii, Hawaii Inst, of Tropical Agric. and

Human Resources Res., Ext. Ser. 83.

Weesner, F. M. 1956. The biology of colony foundation in Reticulitermes hesperus. Univ. Calif.

Publ. Zool., 61: 253-314.

Zimmerman, E. C. 1948. Insects of Hawaii (Vol. 2). Univ. of Hawaii Press, Honolulu.

Received: 21 April 1992; accepted: 19 October 1992

PAN-PACIFIC ENTOMOLOGIST

69(1): 57-70, (1993)

YPONOMEUTA MALINELLUS ZELLER

(LEPIDOPTERA: YPONOMEUTIDAE), A NEW

IMMIGRANT PEST OF APPLES IN THE NORTHWEST:

PHENOLOGY AND DISTRIBUTION EXPANSION, WITH

NOTES ON EFFICACY OF NATURAL ENEMIES

T. R. Unruh, B. D. Congdon, 1 and E. Lagasa 2

United States Department of Agriculture, Agricultural Research Service,

Fruit and Vegetable Insect Research Unit,

Yakima, Washington 98902

Abstract. — Yponomeuta malinellus Zeller is a recent invader of the Pacific Northwest. Its southern

and eastern spread from northwestern Washington was determined with pheromone trapping

surveys. Given the broad distribution of Y. malinellus in Europe and its spread east through the

Cascade Mountains and south into Oregon, we perceive there will be no barrier to its movement

through Oregon into California. Low rates of parasitism in Washington contrast with high

parasitism throughout its native home of temperate Eurasia. Sleeve-cage exclusion of predators

showed that generalist predators caused 40-60% and 20-50% mortality of young larvae and

cocooned larvae or pupae, respectively. Egg mass predation through August of 1989 varied

between 10% and 60% at two localities. Maximum daily pheromone trap catch and egg mass

densities monitored from 1988-1992 indicated populations were relatively stable in the original

infestation area of northwestern Washington.

Key Words. — Insecta, Lepidoptera, Yponomeuta, introduced species, apple pest, predation

Yponomeuta malinellus Zeller (Yponomeutidae), a univoltine defoliator of ap¬

ples found throughout the temperate regions of the Palaearctic, was recently dis¬

covered in Washington and British Columbia. The first reports of the introduction

were two interceptions on nursery trees in 1981 and 1982 on Vancouver Island,

British Columbia (Anonymous 1985); by the summer of 1985, the species was

found to be broadly established in the Fraser River Valley, east of Vancouver,

and in Whatcom Co., Washington, especially in and around Bellingham (LaGasa,

unpublished data). Yponomeuta malinellus first colonized North America 80 years

ago in New York, but these populations were eradicated (Parrott 1913). Recently,

Hoebeke (1987) outlined the status of three Palaearctic congeners of Y. malinellus

that are presumed to be established in the eastern United States: Yponomeuta

cagnagellus (Hubner), Y. padellus (L.) and Y. plumbellus (Denis and Schiffer-

mueller).

Yponomeuta malinellus is a member of the “padellus complex” of small ermine

moths, a group of five morphologically similar species that have been extensively

studied as a model of host-plant associated sympatric speciation (Thorpe 1928,

Menken et al. 1992). Like most species in this group, Y. malinellus is narrowly

oligophagous, using Malus and occasionally Pyrus as hosts (Menken et al. 1992).

Historically, Y. malinellus occurred at low, subeconomic levels punctuated by

sporadic, localized outbreaks that would cause significant damage to apple or-

1 School of Natural and Mathematical Sciences, Seattle Pacific University.

2 State of Washington, Department of Agriculture.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

chards throughout Europe (Affolter & Carl 1986). Such damage to commercial

orchards is now largely precluded by synthetic insecticides used to control codling

moth, Cydia pomonella (L.) (Tortricidae) and leaf rollers in western Europe.

However, in areas where modem synthetic chemicals are used less regularly, Y.

malinellus remains the second most important pest to apples behind the codling

moth (e.g., former U.S.S.R., Nosyreva 1981). In the absence of control by natural

enemies, Y. malinellus represents a significant threat to the development of a

pheromone-based pest management program for apple pests (particularly codling

moth) in North America.

Yponomeuta malinellus has been the target of a biological control program from

1988-1991, the complete details of which will be reported at another time. Herein

we summarize the status of the recent introduction, provide measures of the

impact of natural enemies endemic to northwestern Washington on this exotic

species, and discuss the prospects for its control by endemic and introduced natural

enemies. Parasitism by one introduced species, Ageniaspis fuscicollis Dalman

(Encyrtidae), is reported.

Materials and Methods

Seasonal Biology. — Yponomeuta malinellus larvae were collected weekly from

May to June 1988 and on selected dates in 1989. Specimens were collected from

10 unsprayed Malus trees in a suburban setting (two larval aggregations/tree) on

each date and killed in 70% EtOH. Head capsule widths were measured under a

binocular microscope equipped with an ocular micrometer. Head capsule widths

were used to infer larval instar and, together with field observations of other life

stages and collections in 1989-1991, to outline seasonal phenology.

Pheromone Survey Trapping. — Since 1985, Y. malinellus distribution in Wash¬

ington state has been monitored by the Washington Department of Agriculture

(WSDA), in cooperation with USDA-APHIS, to determine counties to be quar¬

antined for nursery tree export restrictions. Originally, surveys were visual (1986—

1988), but recent identification of the Y. malinellus sex pheromone (McDonough

et al. 1990) has enabled monitoring with synthetic pheromone lures. Pherocon

1-C traps (Trece Incorporated, Salinas, California), baited with rubber septa im¬

pregnated with a two component lure (200 micrograms of Z1 l-14:OH and Z9-

12:Ac in a ratio of 200:3; McDonough et al. 1990) were used in most cases in

1989 and exclusively in 1990. In 1989, some traps placed by USDA-ARS were

baited with a three component lure (100 micrograms of Z1 l-14:OH, Ell-14:OH,

Z9-12:Ac, in a ratio of 100:30:1); both formulations had similar attractiveness

(McDonough et al. 1990; Unruh, unpublished data). Traps were placed in resi¬

dential or feral Malus trees from early to mid-July and removed from mid-August

to early September. Some trap transects, such as those south and east of Puget

Sound in 1989, were monitored semimonthly and, if several traps caught Y.

malinellus, the transect was moved farther south to discern the southern edge of

the distribution. For these transects, intertrap distances were from 1.6-16 km (1-

10 mi). Other transects were examined at the end of the flight season. Results of

similar surveys in British Columbia (1990) and in Oregon (1991) have been

supplied to us and are also reported (D. J. Hilbum, personal communication).

Parasitism Surveys. — Collections and rearing of Y. malinellus larvae and pupae

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

showed that parasitism rates could be accurately assessed from cocooned larvae

and pupae because no parasitoids emerged from earlier life stages. In 1988, co¬

coons were collected from unsprayed Malus trees in suburban and rural settings

of Whatcom County, Washington on 28 Jun to 2 Jul. These were individually

placed into 4 dram glass vials with a cork stopper and were allowed to develop

at 22° (± 2°) C and 50 (± 10) %RH with 16:8 photophase: scotophase. In 1989,

cocoon collections were made from unsprayed Malus in San Juan and Whatcom

Counties on 16 Jun to 14 Jul and were either individually isolated or pupal clusters

were placed in resealable sandwich bags. In 1990, cocoons were collected from

Whatcom County on 28 Jun to 17 Jul and cocoon clusters were placed in either

plastic vials (40 dram) or sandwich bags. After parasitoid emergence ceased, the

remaining host cocoons were dissected under a binocular microscope. Percentage

parasitism for all 3 years was based on the number of cocoons from which a

parasitoid emerged, divided by the total number of cocoons from which insects

emerged, or which died, as pupae. Adult Y. malinellus found dead within the

pupal cases were considered emerged adults. A few fly puparia dissected from Y.

malinellus pupae that did not eclose are reported as Tachinidae. All other un¬

emerged host cocoons, whether due to predation or unknown causes, are reported

as unknown mortality.

Predator Exclusion Studies. —Two forms of exclusion cages were used to de¬

termine the impact of endemic predators on the second through fifth larval stadia

in 1989. Complete exclusion cages, designed to exclude both insect and bird

predators, consisted of a 30 cm diameter by 1-1.5 m long cylinder of white, nylon,

organdy screen (300 Denier Nylon, 39 strands/cm [100/inch]) secured at each end

with tightened wire bands over a branch containing a larval colony. Bird exclusion

cages consisted of two or more layers of plastic bird netting (0.64 cm [0.25 inch]

mesh) wrapped around a branch containing larvae and held in place with staples.

Marked, uncaged branches containing a single larval brood were used as experi¬

mental controls (= natural mortality).

Unsprayed, residential Malus trees were inoculated with larvae to artificially

establish colonies for predator exclusion studies; thus, the number of larvae present

at the beginning of the experiment was known. The day before inoculating, the

trees were pruned to minimize larval movement and to accommodate exclusion

cages. Within 8 hours of collection, larvae of each colony were counted and moved

to clean, excised apple leaves in 15 cm diameter plastic petri plates that were

covered and left overnight at room temperature. The following morning all col¬

onies had established tents on the excised leaves. These artificial colonies (ACs)

were returned to their collection sites and randomly assigned to prepared branches

and covered with an exclusion cage or, for the controls, left uncovered. ACs were

attached to a vigorous cluster of leaves by stapling a thin (2-3 cm) strip of paper

around the cluster and the infested leaf.

ACs were visually inspected each week after inoculation and those that failed

to establish or were contaminated from naturally occurring colonies (as evinced

by the copious webbing left by larval colonies and the increased number of larvae

in the AC) were excluded from the study. ACs were established at two sites in

Bellingham, Washington on 12, 17, 24 and 31 May and removed on 6 to 7 Jun.

The ACs setup on the first two dates consisted of small larvae (second, third and

small fourth instar) and were pooled for statistical analyses. Those on the third

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

and fourth dates were relatively larger (large fourth and fifth instar) and were also

pooled.

A similar experiment was done with pupal clusters, except that leaves to which

clusters adhered were carefully removed, cocoons enumerated, and then stapled

through extra webbing directly to undamaged leaves. Cocoon clusters were then

covered with one of the two exclusion cages used for larvae or left exposed. Forty

pupal clusters were set up on 6 Jun (20 exposed, 10 with bird exclusion and 10

with complete exclusion; half of each type in each study site) and removed on 28

Jun. Intact pupae and those from which moths successfully emerged were counted

as survivors; missing larvae or pupae and dead ones with feeding damage (yellow

hemolymph stains, etc.) were scored as dead.

Finally, two exclusion treatments were used to measure egg mass predation: (1)

all predators were excluded with close-fitting organdy sleeves, and (2) walking

predators were excluded with a 1 cm wide band of Stickem®, 2-5 cm proximal

and distal to the egg mass. Eighty naturally occurring egg masses were monitored

(40 exposed and 20 for each exclusion treatment) at each of two sites on 6 and 7

Aug 1989. A census of egg masses was taken on 12 Sep 1989. A census of a subset

of surviving hibemacula (= egg case with diapausing/quiescent larvae) was taken

again on 15 Mar and 9 May 1990.

Differences among exclusion treatments for the two larval size classes and

cocoons were analyzed separately using factorial analysis of variance (ANOYA)

of untransformed survival proportions, with exclusion treatment and site as crossed

factors. (Arcsine transformation gave qualitatively similar results, but because a

few cases had more larvae at the end of exposure than counted at the onset and

because the arcsine transform is undefined for values greater than one, it was not

used.) The initial number of larvae or pupae in each AC was treated as a covariate.

Comparisons between means employed Tukey’s Studentized (HSD) range test

(Proc GLM: SAS 1988). Differences in the frequency of intact egg masses versus

those empty or missing at the census intervals were analyzed using Chi square.

Population Density Estimates.— In 1989-1992, samples consisting of 30 vig¬

orous branches (with developed terminal bud) were taken from five trees at each

of four sites early each year prior to bud burst and larval exit from hibemacula.

All hibemacula on the terminal two seasons of wood growth were counted under

a binocular microscope. The same five trees were sampled at each site each year,

minimizing year to year variance.

Adult population trends were also monitored using pheromone traps baited

with the two component lure as described for survey trapping. Four sites were

monitored in 1988 and nine were monitored during 1989-1991 flight seasons.

Traps (Pherocon 1-C, Trece) were changed approximately every two weeks (range

10-20 days) and traps at all sites were replaced on the same day. Only the second

half of the flight season for 1988 was trapped because that is when the pheromone

became available. The numbers of traps deployed at each site were two in 1988,

three to 14 in 1989, and three in 1990 and 1991. Yponomeuta malinellus males

are typically caught within 10 m of their release site in mark recapture studies

(Menken et al. 1992; Unruh, unpublished data) and intertrap distances exceeded

10 m at all sites. Data were expressed as the number of males/trap/day for each

trapping interval. Mean trap catch for the trapping interval with highest capture

rate in each year at each site is reported.

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

Head Capsule Width (mm x 10)

ADULTS

EGGS

MAY

JUNE

JULY AUGUST SEPT

Figure 1. Head capsule widths for five larval instars of Y. malinellus and approximate duration

of all life stages in the field in Whatcom County, Washington. Based on 20 tents collected weekly from

early May to late Jun 1988 and on selected dates in 1989.

Results and Discussion

Life History.— The frequency distribution of head capsule widths of Y. mali¬

nellus larvae fell in five discrete groups (Fig. 1); based on inspection of the dis¬

tributions we chose 0.25, 0.4, 0.7 and 1.15 mm as head capsule growth intervals

between instars. Given these intervals, head capsule widths averaged [SEM] 0.1891

mm [.0023], 0.3317 mm [.0011], 0.5828 mm [.0028], 0.8998 mm [.0035] and

1.373 mm [.0033] for first through fifth instars, respectively.

The seasonal biology of Y. malinellus in northwestern Washington is also di¬

agrammed in Fig. 1 and is similar to that reported for the Palaearctic (e.g., Beime

1943, Junnikkala 1960). Eggs were laid in an overlapping pattern in an irregular

mass about 5 mm in diameter; egg laying commenced in mid-summer (earliest

observed 6 Jun 1987). In Washington, egg masses consisted of about 50 eggs (x

= 45.7, S.D. = 14.2, range 16-82, n = 58; 1988). From cage studies in Sweden,

Junnikkala (1960) found that females lay an average of 1.37 egg masses. Egg

masses were typically found on one to three year old wood, rarely on the growth

of the current season. The eggs hatched about three weeks after oviposition and

first instar larvae remained under the hibemaculum, which consists of upper

surface of the egg mass, through winter until early spring.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Figure 2. Geographic pattern of pheromone trap catch for 1989-1991 in Washington, five Oregon

counties and the area bordering Washington in southern British Columbia. Infestation boundaries

based on visual surveys in 1988 are also depicted as a shaded area.

Larvae abandoned hibemacula and began leaf mining in early April with the

first sign of leaf tissue on apple. Newly established mines, always on young leaves,

were observed until late May. The second through fifth instars fed externally on

leaves and spun loose white-grey webbing (tents) around and near attacked leaves.

All larval stages formed aggregations, presumably of the siblings from the same

egg-mass. High population densities and disturbance by predators appeared to

cause confluence of aggregations or their partial dissolution into smaller groups,

respectively.

Cocoon spinning and pupation also occurred gregariously, beginning as early

as late May but normally in mid June in western Washington. In high density

infestations, where trees were largely or entirely defoliated, cocooning occurred

in irregularly shaped super aggregations (composed of multiple sibships) in the

crotches of tree branches, below branches, under large bark flakes, in holes in the

trunk, etc., and large masses reached 10 cm in diameter. In moderate to light

infestations, cocoons were typically found as isolated clusters on the underside of

undamaged leaves.

Adult eclosion was first observed about 2 weeks after cocooning; emergence of

adults in the laboratory was spanandrous with the bulk of the males emerging

about 3 days before the females. First male trap catch followed first observed

eclosion by 1-2 weeks and first observations of oviposition or of egg masses were

2-3 weeks after the onset of eclosion. This timing is consistent with observation

in Europe—that adults are not sexually mature at eclosion, that mating occurs

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

about one week later, and oviposition commences 2 weeks after eclosion (Junik-

kala 1960, Menken et al. 1992).

Distribution.— Figure 2 shows the geographic distribution of Y. malinellus in

Washington based on pheromone trap catches from mid Jul through mid Sep

1989 to 1991. Also displayed are the distributions as determined by visual

surveys in 1988, representative positive sites for southern British Columbia east

of the Cascade Mountains, and positive traps for northern Oregon in 1991.

For Washington, we refer to two regions, east and west, separated by the crest

of the Cascade Mountains and seen in Fig. 2 as the eastern borders of Whatcom,

Skagit, King, Pierce, Lewis, and Skamania Counties. In 1989, 312 traps placed

in nine western counties produced 81 positive trap sites and 500 moths. In con¬

trast, no moths were captured in 58 traps arrayed in four eastern counties (Chelan,

Douglas, Kittitas, Yakima). In 1990, 480 traps placed in four southwestern coun¬

ties produced 53 positives and 117 moths, demonstrating the moth had reached

the Columbia River in western Washington. Fourteen counties in eastern Wash¬

ington were added to the survey in 1990 (Asotin, Benton, Columbia, Ferry, Frank¬

lin, Garfield, Grant, Kickittat, Okanogan, Pend Oreille, Spokane, Stevens, Walla

Walla, Whitman). Of 825 traps placed in 18 eastern counties, 21 were positives

with 34 moths in four counties. These four counties included two (Chelan and

Kittitas) that were trapped with no captures in 1989, with traps placed in the

same areas, if not the same trees, in both years. In 1991, survey trapping was

restricted to eastern Washington and two counties along the Columbia River Gorge

(Skamania and Klickitat). Columbia, Pend Oreille, and Whitman Counties were

not trapped in 1991. Of 1130 traps in the remaining 15 counties, 62 caught 145

moths with new records in Douglas, Klickitat, Spokane, Stevens and Yakima

Counties. Because these areas were trapped the previous year, the results suggest

trap catch was contemporaneous with colonization of these counties.

Also in 1991, the Oregon Department of Agriculture trapped in 25 counties;

including counties bordering the Columbia River, counties surrounding the greater

Portland area, and in most areas of high human density; including down the

Willamette Valley and in towns along Interstate Highway 5 to the California

border. Captures, 51 moths in 34 traps of 1329 deployed, were restricted to the

five counties depicted in Fig. 2 (Columbia, Washington, Multnomah, Clackamas

and Hood River; D. J. Hilbum, personal communication). These results indicate

that the southern edge of the distribution was the northernmost extent of western

Oregon in 1991.

In summary, all pheromone trap transects west of the Cascade Mountains caught

males in 1989, including those extending up the western slope along the three

major trans-Cascadian mountain passes in Washington (Baker, Stevens and Sno-

qualamie). These were followed by moth catches on the eastern slopes of the

Cascades east of the same mountain passes in Chelan, Okanagon and Kittitas

Counties in 1990. However, only Chelan and Kittitas were trapped in 1989; hence,

only there can we have some confidence that the colonization was recent. A similar

expansion eastward up the Columbia Gorge was evident. Because these mountain

passes and the foothills on either side are not heavily populated, we infer that the

spread of Y. malinellus through the Cascade Mountains was unaided by man.

The surveys for Y. malinellus in British Columbia (H. Nichols, personal com¬

munication) revealed a similar pattern of spread from the original infestation area

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Parasitism rates of Yponomeuta malinellus Zeller for 1988-1990 by parasitoid species.

Year

Number

sites

N,«

% Y.m.

C.c.

Tach

H.p.

I.q.

D.c.

Unk

A.f.

n 2

1988

857

78.9

0.93

0.58

0.70

18.9

1989

13,478

96.12

0.13

0.32

0.12

0.49

0.04

2.7

0.35

12,026

1990

6430

90.87

1.30

0.40

0.33

1.24

0.02

5.4

0.48

6290

a N,, number of cocoons reared; % Y.m., percent emerged as Y. malinellus or died in pupal case as

fully formed adults; C.c., percent emerged Compsilura concinnata (Meigen); Tach, percent of unde¬

termined tachinids that were probably either C.c. or H.p. but deteriorated, or remained as puparia;

H.p., percent Hemisturmia parva (Bigot); I.q., percent Itoplectis quadricingulata (Provancher); D.c.,

percent Dibrachys cavus (Walker); Unk, percent unknown mortality of cocooned larvae and pupae;

A.f., percent Ageniaspis fuscicollis Dalman; N 2 , the subset ofN, taken from sites where A.f was released

and used for calculating A.f. parasitism rates.

in the Fraser River delta (Anonymous 1985). In 1989, limited trapping surveys

showed the Fraser River Canyon to be generally infested up to Lillooet and east

of the Cascade crest near Kamloops and Sicamous. The infestation also extended

south into the Canadian Okanogan to Kelowna and to the United States border

near Grand Forks, British Columbia. Only the southern edge of this distribution

is depicted in Fig. 2. It is likely that Y. malinellus in eastern British Columbia

also arrived by dispersing through the low pass(es) in the Canadian Cascades.

Parasitism and Predation.— Parasitism of Y. malinellus, based on cocoon col¬

lections from 1988 to 1990, is summarized in Table 1. No parasitoids were

discovered emerging from earlier life stages. Combined parasitism by two tachinid

species, Compsilura concinnata (Meigen) and Hemisturmia parva (Bigot), was

about equal to that by the ichneumonid Itoplectis quadricingulata (Provancher)

and was about 2-3% altogether. All three of these parasitoids are polyphagous.

Compsilura concinnata is of exotic origin and was introduced in large numbers

in several biological control programs, notably against the satin moth, Stilpnotia

salicis (L.) (Lymantriidae), in Washington between 1928 and 1935 (Clausen 1978).

Itoplectis quadricingulata has a host range that includes many microlepidoptera

and sawflies (Carlson 1979) and is common in the forests of the northwest (Ryan

1971). Hemisturmia parva has a more narrow host range that includes seven

families of Lepidoptera (as H. tortricis Coquillett: Amaud 1978). The gregarious

parasitoid Dibrachys cavus (Walker) (Pteromalidae) was uncommon and may have

acted as either a primary or, more likely, a hyperparasitoid. Total parasitism by

these four “endemic” parasitoids was quite low and never exceeded 4% in any

year. A trend of increasing parasitism rates, which would suggest adaptation to

this exotic host, was not evident.

In 1989, the exotic egg parasitoid, A. fuscicollis, was detected at nine of 33 sites

at which we had released it in 1988 (release details to be presented elsewhere).

Recoveries in 1990 at four sites where A. fuscicollis was released in 1988 but not

in 1989 showed that this parasitoid is established. Introductions into British

Columbia, beginning in 1987 by Agriculture Canada in conjunction with the

Commonwealth Institute of Biological Control, CAB, have also resulted in suc¬

cessful establishment of this parasitoid (Frazer 1989). Through 1990, A. fuscicollis

had not added significantly to parasitism rates of Y. malinellus in Washington.

Exclusion Cage Studies. — Exclusion cage experiments demonstrated significant

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

.4 -1

\x4\i Exposed

Bird Exclusion

Complete Exclusion

1.0 -

> - 8

ox .6

X -XL

7 /a

T J

Plot 1 Plot 2

Young larvae

to cocooning

Plot 1 Plot 2

Old larvae

to cocooning

Plot 1 Plot 2

Cocoons

Figure 3. The proportion survival of Y. malinellus larvae and cocooned larvae or pupae in exclusion

cage experiments of 1989. See text for details of treatments. Within groups, significantly different

treatments do not share heavy crossbars (Tukey’s HSD, alpha = 0.05).

levels of predation in three life stages of Y. malinellus : free living larvae, cocooned

larvae and egg masses (Fig. 3). Survivorship from small through large larval stages

(early May through early June) was significantly increased by predator exclusion

at both study plots. An ANOVA model that included study plot, exclusion treat¬

ment, and their interaction as factors, with the number of larvae in each AC at

the start of the experiment as a covariate, explained 48% of the variation in

survivorship proportions and was highly significant (P = 0.0001). Exclusion treat¬

ments were significant (P = 0.0001) as was the covariate (number of larvae setup,

P = 0.03); all other effects were insignificant. Bird exclusion gave survivorship

intermediate (plot 1) or equal (plot 2) to that provided by complete exclusion

(Fig. 3). For the second experiment with large larvae (late May to early June) the

ANOVA model explained only 14% of the variation in survival proportions and

was not significant (P = 0.1). However, plot differences caused a significant effect

(P = 0.03) and modest, nonsignificant differences in survivorship associated with

exclusion treatments were evident at plot 2 (Fig. 3).

In the experimental exclusions with pupae, the ANOVA model explained 44%

of the variation in survival and was significant (P = 0.005); exclusion treatments

were the only significant effect (P = 0.005). Exposed pupal clusters had lower

survivorship than those under bird exclusion or complete exclusion. The pattern

observed for the young larvae to cocooning was again evident for cocoons; bird

predation accounted for most mortality, especially at plot 2 (Fig. 3).

Qualitative observations at other study sites showed the diversity of insect

predators (e.g., wasps and ants) was abundant and they often fed on both large

Vol. 69(1)

THE PAN-PACIFIC ENTOMOLOGIST

Figure 4. Egg mass (= hibemacula) densities per 30 branch sample (per tree) for Y. malinellus at

4 sites in Whatcom County, Washington. Standard errors are not shown but averaged 44% of the

mean (range 25% to 66%).

and small Y. malinellus larvae. Large numbers of a common hornet, Vespula sp.,

were seen taking larvae at one site. In our exclusion studies, experimental variation

was large for bird exclusion treatments because several ACs were excluded from

analyses when larval aggregations moved outside of the bird netting enclosures.

This suggests that bird netting allowed free access for insect predators. However,

this may be true only for predators that forage by walking; flying foragers, such

as Vespula, would likely be impeded by bird netting. Indirect evidence of bird

activity (i.e., droppings) was also commonly observed and starlings ( Sturnus ) were

often seen foraging in infested trees. Beime (1943) claimed birds were significant

mortality agents of Y. malinellus in Ireland, and Alfolter & Carl (1986) reported

records of starlings feeding on Y. malinellus.

Only 1% of egg masses under exclusion treatments (n = 79) were destroyed

from 7 Aug to 12 Sep 1989 at both study sites. However, 36% of exposed egg

masses (n = 80) perished over the same interval. Most of this mortality occurred

at site 1 (25 of 40 exposed egg masses), producing statistical significance of ex¬

clusion treatments (site 1: Chi-Square, df = 2, n = 80, P = 0.0001). Because

tanglefoot barriers excluded virtually all mortality one may infer the mortality

agents were small and approached egg masses by walking. We made no systematic

search for the organism(s) responsible for this mortality but Smith (R. B. Smith,

personal communication) found that a mite, Balaustium sp. (Erythraeidae), caused

similar levels of mortality in nearby British Columbia. Census of a subset of

hibemacula (= egg masses with hatched larvae in diapause/quiescence) on 15 Mar

1990 showed mortality was 9% in exposed hibemacula (n = 33) and was not

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

Figure 5. Maximum pheromone trap catch (male moths/trap/day) for 1988-1991 at 4 to 9 sites

in Whatcom County, Washington. Traps were changed every 2 weeks from the beginning of flight

season (except for 1988; see text). Inset shows a representative flight curve monitored at one study

site in 1991. The maximum value, 5.5 males/trap/day, represents a single datum in the body of the

figure.

statistically different from cage (0%, n = 37) or sticky barrier (6%, n = 16) exclusion

treatments (P > 0.3 at each site). Similarly, census on 9 May showed 100% of

exposed (n = 32) hibemacula and hibemacula protected by sticky barriers (n =

15) survived to larval egress as did 96% of hibemacula in cages (n = 22).

Population Trends. — Egg mass samples over 4 years showed similar population

trends at four study sites (Fig. 4). The average number of egg masses per 30 branch

sample (five trees/site) increased two to five fold from 1989 to 1990 and generally

decreased from 1990 through 1992.

The maximum trap catch (mean number of males/trap/day) taken from the

seasonal flight curve at each study site (5.5 in inset) was used to summarize flight

each year at nine study sites and is depicted in Fig. 5. Generally higher trap catches

in 1989 were consistent with the pattern observed for hibemacula densities, al¬

though there were exceptions. Maximum daily trap catch varied only 2.5 fold, at

most, over years within each site.

Both egg mass densities and pheromone trap catches indicate that Y. malinellus

populations have been relatively stable over the last 4 years in Whatcom County.

High trap catches at sites where infestations were visually obvious (the main

infestation areas in Whatcom County) versus low trap catches in newly infested

southern counties where densities were too low to be detected visually during pest

surveys suggest that pheromone traps will provide some measure of regional

population trends across years. Thus, traps should be valuable to assess the long¬

term effect of introduced biological agents on regional population densities.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

However, we do not suggest that pheromone trap catch or egg mass sampling,

as employed here, provide resolution adequate to study site-specific population

dynamics. We have observed striking year-to-year variation in apparent densities

of larvae and cocoons (stages for which we have been unable to develop an

objective sampling method). For example, we observed Y. malinellus larval pop¬

ulations extirpated in April 1989 at several sites in Whatcom County when trees

were completely defoliated by the winter moth, Operophtera brumata (L.) (Ge-

ometridae), prior to the completion of larval development of Y. malinellus. At

one of these sites, we monitored male trap catch before and after this event. A

decline of only 50% in peak trap catch was evident in the flight following larval

extirpation (10 in 1989 versus 20 in 1988), suggesting that a significant percentage

of trap catch are males from off site.

Conclusion

Our observations of Yponomeuta malinellus in Washington show its phenology

is similar with that reported throughout the Palaearctic. From survey trapping,

we infer that the moth is capable of colonizing new areas over mountain passes

that may provide no suitable hosts for 50 to 100 km. Populations appear to be

regionally stable in the original infestation area of Whatcom County and ongoing

monitoring will determine how long it will take for newly colonized areas (e.g.,

Yakima County) to reach the high levels that now are characteristic of north¬

western Washington.

In pesticide-free settings in its native range, Y. malinellus is host to a large

complex of natural enemies that are well known and produce high parasitism rate

(20-90%) (e.g., Beime 1943, Junnikkala 1960, Friese 1963, Dijkerman 1987).

These authors and a host of others (reviewed in Affolter & Carl 1986) consider

Y. malinellus to be regulated by its parasitoid complex, together with generalist

predators, throughout the Palaearctic. Prior to use of synthetic insecticides, Y.

malinellus was a significant pest of apples, second in importance to the codling

moth, C. pomonella, especially in central and northern Europe (Faes 1928, Jancke

1933, Affolter & Carl 1986). In countries where economic development has lagged

and synthetic pesticide use has remained restricted, Y. malinellus has continued

to show periodic outbreaks that can cause severe, region-wide crop damage (e.g.,

Vaclav 1958, cited by Affolter & Carl 1986; Nosyreva 1981).

Yponomeuta malinellus does not pose a serious threat to conventional apple

producers in North America if an early cover spray of organophosphate insecticide

is used for codling moth control. However, if orchardists substitute sex pheromone

based mating disruption for codling moth control (Howell et al. 1992) and other

pesticide applications are made based on need, then Y. malinellus may become

one cause for periodic pesticide applications.

The prognosis for control of populations infesting feral and residential Malus

is uncertain. The constant low levels of parasitism by generalist “endemic” species

indicate that they will not control Y. malinellus. However, our data suggest that

endemic predators do produce significant mortality that may be largely responsible

for preventing even more damaging levels of Y. malinellus in the western U.S.A.

Also, increasing parasitism rates by the introduced parasitoid A. fuscicollis in 1991

(Unruh, unpublished data) suggest that this species may eventually contribute to

lowering populations to densities more closely approximating those in Europe.

1993 UNRUH ET AL: YPONOMEUTA BIOLOGY AND DISTRIBUTION

Acknowledgment

Careful technical assistance by Richard Short made this work possible. Added

assistance of Mike Haskett and John Wraspir (Washington State Dept, of Agri¬

culture, Yakima and Bellingham) and Brad Higbee (USDA, Yakima) was critical.

Early efforts by James Krysan (USDA, Yakima) are acknowledged as are his

comments on the manuscript. Vic Maestro (USDA-APHIS, OTIS Development

Center) and Les McDonough (USDA, Yakima) supplied pheromone for survey

and monitoring traps. Insect identifications were provided by R. W. Carlson

(Ichneumonidae), E. E. Grissell (Pteromalidae) and N. E. Woodley (Tachinidae)

(all of the Systematic Entomology Laboratory, USDA, ARS, Beltsville, Maryland).

Additional reviews of the manuscript by H. R. Mofhtt, H. H. Toba, D. R. Horton

(USDA, Yakima) and R. E. Hoebeke (Cornell) are gratefully acknowledged. Har¬

riet Nicholls of Agriculture Canada and Dan Hilbum of the Oregon Department

of Agriculture kindly provided pheromone trapping records for British Columbia

and Oregon, respectively.

Literature Cited

Affolter, F. & K. P. Carl. 1986. The natural enemies of the apple ermine moth Yponomeuta malinellus

in Europe. A literature review. CAB International Institute of Biological Control, Delemont,

Switzerland (November 1986).

Anonymous. 1985. Apple ermine moth new to the United States. U.S. Dept. Agric., Anim. Plant.

Health Insp. Serv., Plant Prot. Quar. Plant Pest Updates, 1-2.

Amaud, P. 1978. Host parasite catalogue of North American Tachinidae. USDA Misc. Publ., 1319.

Beime, B. P. 1943. The biology and control of the small ermine moths (Hyponomeuta spp.) in

Ireland. Econ. Proc. R. Dublin Soc., 3: 191-220.

Carlson, R. W. 1979. Ichneumonidae. pp. 315-739. In Krombein, K. V., P. D. Hurd, D. R. Smith

& B. D. Burks (eds.), Catalog of Hymenoptera in America North of Mexico. Volume 1: Symphyta

and Apocrita (Parasitica). Smithsonian Institution Press, Washington, D.C.

Clausen, C. P. 1978. Lymantriidae. pp. 195-204. In Clausen, C. P. (ed.). Introduced parasites and

predators of arthropod pests and weeds: a world review. USDA Agriculture Handbook No.

480. Washington, D.C.

Dijkerman, H. J. 1987. Parasitoid complexes and patterns of parasitization in the genus Yponomeuta

Latreille (Lepidoptera, Yponomeutidae). J. Appl. Entomol., 104: 390-402.

Faes, H. 1928. La lutte contre les chenilles fileuses ou chenilles d’Hyponomeutes. Ann. Agric. Suisse,

29: 520-533.

Frazer, B. D. 1989. Ageniaspis fuscicollis (Dalman), a parasite of the apple ermine moth. Biocontrol

News (Agriculture Canada), 2: 24.

Friese, G. 1963. Die parasiten der palaarktischen Yponomeutidae (Lepidoptera, Hymenoptera,

Diptera). Beitr. z. Entomol., 13: 311-326.

Hoebeke, E. R. 1987. Yponomeuta cagnagellus (Lepidoptera: Yponomeutidae): a palearctic ermine

moth in the United States, with notes on its recognition, seasonal history, and habits. Ann.

Entomol. Soc. Am., 80: 462-467.

Howell, J. F., D. F. Brown, T. R. Unruh, J. L. Krysan, C. R. Sell, P. A. Kirsch & A. L. Knight. 1992.

Control of codling moth, Cydia pomonella (L.), in apple and pear with sex pheromone-mediated

mating disruption. J. Econ. Entomol., 85: 918-925.

Jancke, O. 1933. Gespinstmotten als Grosschadlinge an Obstbaumen. Arb. biol. Reichanst. Land-

u. Forstw., 20: 431-441.

Junnikkala, E. 1960. Life history and insect enemies of Hyponomeuta malinellus Zell. (Lepidoptera:

Hyponomeutidae) in Finland. Ann. Zool. Soc. “Vanamo,” 21: 1-44.

McDonough, L. M., H. G. Davis, C. L. Smithhisler, S. Voerman & P. S. Chapman. 1990. Apple

ermine moth, Yponomeuta malinellus Zeller two components of female sex pheromone gland

highly effective in field trapping tests. J. Chem. Ecol., 16: 477-486.

Menken, S. B. J., W. M. Herrebout & J. T. Wiebes. 1992. Small ermine moths (Yponomeuta): their

host relations and evolution. Annu. Rev. Entomol., 37: 41-66.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Nosyreva, R. D. 1981. Systematic measures for the protection of fruit trees from pests and diseases.

Zaschita Rastenii, 11: 55-57.

Parrott, P. J. 1913. New destructive insects in New York. J. Econ. Entomol., 6: 61-68.

Ryan, R. B. 1971. Interaction between two parasites, Apechthis Ontario and Itoplectis quadricingu-

latus. 1. Survival in singly attached, super-, and multiparasitized greater wax moth pupae. Ann.

Ent. Soc. Amer., 64: 205-208.

SAS. 1988. SAS/STAT User’s Guide (Release 6.03). SAS Institute Inc., Cary, North Carolina.

Thorpe, W. H. 1928. Biological races in Hyponomeuta padellus. J. Linn. Soc. (London), 36: 621—

636.

Vaclav, V. 1958. Importance of parasites on reducing numerousness of populations of Hyponomeuta

malinella Zell, and H. padellus L. in Bosnia and Herzegovina. Plant Protection, Beograd, 49/

50: 113-119. (In Serbian)

Received 17 April 1992 ; accepted 28 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 71-76, (1993)

EFFECTS OF TEMPERATURE ON DEVELOPMENT OF

BACTROCERA ZONATA (SAUNDERS)

(DIPTERA: TEPHRITIDAE)

Zafar Qureshi, 1 Talib Hussain, 1 James R. Carey, 2 and

Robert V. Dowell 3

Atomic Energy Agricultural Research Centre,

Tando Jam, Pakistan

department of Entomology, University of California,

Davis, California 95616

California Department of Food and Agriculture,

1220 N Street, Sacramento, California 95814

Abstract.— We measured the developmental times and survivorship of the immature stages of

Bactrocera zonata (Saunders) and the longevity, preovipositional period and fecundity of adult

flies at five temperatures between 15° C and 35° C. Egg hatch significantly increased with tem¬

perature from 15° C (51%) to 25° C (91.3%), and then decreased to zero at 35° C. No larvae

completed development at 15° C or 35° C. Larval and pupal survival were greatest at 25° C, as

were female fecundity (eggs laid) and fertility (% egg hatch). Developmental times for all stages

were inversely related to temperature. Egg development was fastest at 25° C and 30° C, although

larval, pupal and ovarian development were fastest at 30° C.

Key Words. — Insecta, Bactrocera zonata, temperature dependent development, immature sur¬

vival, adult preovipositional period, fecundity and fertility

Temperature has been shown to be an important factor influencing the devel¬

opment of immature stages and ovaries of a number of economically important

fruit flies (Tephritidae) (Moore 1960, Tsiropoulos 1972, Saeki et al. 1980, Oku-

mura et al. 1981). Models describing the influence of temperature on develop¬

mental rate have been used to determine when to apply fruit fly control and

eradication measures, and to determine the possible geographic distribution of

various fruit fly species (Saeki et al. 1980, Meats 1981, Tassen et al. 1983).

Bactrocera zonata (Saunders), the peach fruit fly, is found in Egypt, Pakistan,

Burma, India, Thailand, and Indonesia (Kapoor et al. 1980), where it attacks a

range of fruit, including apple, guava, peach and pear (Nair 1975, Kapoor et al.

1980, Kapoor & Agarwal 1983). In India, it is as, or more, important a pest of

commercial and dooryard crops than its better known cogenor B. dorsalis (Hendel),

the oriental fruit fly (Kapoor & Agarwal 1983).

The recent discovery and successful eradication of several isolated infestations

of B. zonata in California (Dowell 1988; Dowell & Gill 1989; RVD, unpublished

data) have highlighted the need for data on the biology of this important fruit

pest. Reported here are the effects of temperature on the development and survival

of life stages of B. zonata.

Materials and Methods

Rearing of Test Insect. — Guava infested with Bactrocera zonata were placed in

wooden trays on sterilized sand moistened with distilled water until the larvae

emerged. The resulting pupae were isolated and kept in wire cages (45 x 45 x

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

55 cm) until adult emergence. This colony was reared through one generation to

increase the number of flies before the experiments started. The rearing conditions

were 25 ± 2° C, 65 ± 5% RH and a 14:10 LD cycle. The adults were provided

water, protein hydrolysate (enzymatic) and sugar.

The larval diet was 100 g wheat shorts, 17 g brewer’s yeast, 33 g sugar, 3.5 g

agar, 0.5 g Nipagin, 20 ml HC1 and 400 ml water. The wheat shorts, brewer’s

yeast, sugar and Nipagin were mixed together. The agar was dissolved in boiling

water, and after cooling to 15° C it was mixed with the other ingredients, with

the HC1 added last. The mixture was blended for 2-3 minutes to a smooth

consistency. The prepared medium had a pH of 4.5. The medium was poured

into 15 petri dishes (9 cm diameter). Tissue paper was placed on the diet for

seeding larvae (100 larvae per petri dish).

Temperature Studies.—We studied the effect of temperature on the life stages

of B. zonata in Hotpack® programmable refrigerated incubators, each equipped

with two 20 watt fluorescent lights and set at a 14:10 LD cycle. Test temperatures

ranged from 15° C to 35° C in 5° increments. Fluctuation at each temperature was

± 1° C. The procedures followed for testing the different stages are given in seria-

tum. Each test was replicated three times.

Eggs. — One hundred eggs obtained from the colony were placed on filter paper

moistened with distilled water at each test temperature. After 24 h, each petri

dish was examined hourly for egg hatch. After hatch was completed, unhatched

eggs were counted and hatch percentage determined.

Larvae and Pupae.—One hundred neonate larvae were divided among three

petri dishes kept at each test temperature. When the larvae reached third instar,

the petri dishes were placed on sterilized sand in a covered enamel tray for

pupation. Pupae were removed daily from the sand and kept in petri dishes until

adult eclosion. Larval and pupal survival were computed from pupal recovery

and adult emergence data respectively.

Adults. — The adults were sexed and 30 pairs were confined in each of three

screen cages (25 x 25 x 35 cm) at each test temperature. Water, sugar and protein

hydrolysate (enzymatic) were provided as food and mortality was recorded daily.

An egging receptacle, a yellow plastic glass with fine holes in its sides and smeared

internally with guava juice, was placed in each cage. The egging receptacle was

replaced daily until all females had died. Eggs were removed daily from the

receptacles and kept on moistened filter paper to determine percent hatch.

Following the above procedures, the effects of temperature on B. zonata de¬

velopment and survival were evaluated in four sets of experiments: (1) egg to

adult stage, (2) larva to adult, (3) pupa to adult and (4) adults alone. This procedure

allowed us to determine whether the flies acclimated to the colony rearing tem¬

perature. Analysis of variance tests were used to determine differences between

developmental time, percent survival (arcsine squareroot of percent transformed)

and adult fecundity data within and among experiments.

Results

Egg to Adult.— The effects of temperature on survival of B. zonata life stages

are shown in Table 1. Egg hatch significantly increased with temperature from

15° C (51%) to 25° C (91.3%) and then decreased to zero at 35° C. No larvae

completed development at 15° C or 35° C. Larval and pupal survival, and male

1993 QURESHI ET AL.: DEVELOPMENT OF BACTROCERA ZONATA

Table 1. Effect of temperature on survival of egg, larval, and pupal stages of Bactrocera zonata

that were reared on artificial diet.

Test

°c

Stage specific survival (%) a

Egg

Larvae

Pupae

Egg to adult

51.00 [A]

—

76.67 [B]

71.28 [C]

93.9 [B]

91.33 [C]

93.78 [A]

97.66 [A]

55.67 [C]

79.66 [B]

81.94 [C]

Larvae to adult b

62.67 [C]

88.86 [B]

89.00 [A]

95.50 [A]

72.33 [B]

88.93 [B]

Pupae to adult b

78.67 [C]

92.33 [B]

97.67 [A]

95.00 [A]

5.00 [D]

a Means followed in square brackets by different capital letters within each test differ at P < 0.05;

n = 100 individuals per replicate, with three replicates conducted.

b Immature stages reared at 25° C prior to exposure to test temperature in latter two tests.

longevity were greatest at 25° C. Female longevity was the same at 20° C and 25°

C. Longevity of both sexes was reduced by 59 to 74 days as the rearing temperature

was increased from 25° C to 30° C. Female fecundity (eggs laid) and fertility (%

egg hatch) were greatest at 25° C (Table 2).

Developmental times for all stages were inversely related to temperature (Table

3). Egg development was fastest at 25° C and 30° C, and larval, pupal and ovarian

development were fastest at 30° C.

Larva to Adult. — With one exception, the trends described previously were seen

when starting with neonate larvae instead of eggs: larval and pupal survival, and

female fecundity and fertility were greatest at 25° C, no larvae completed devel¬

opment at 15° C or 35° C, no adults laid eggs at 30° C, adult longevity decreased

between 25° C and 30° C, and developmental times were inversely related to

temperature. In this test, however, adult longevity was inversely related to tem¬

perature with significant decreases at 25° C for both sexes (Tables 1-3).

Pupa to Adult.— Pupal survival was greatest at 25° C and 30° C but decreased

at 35° C. No females laid eggs at 15° C, 30° C or 35° C and both fecundity and

fertility were greatest at 25° C. Adult longevity significantly increased from 15° C

to 25° C and then significantly decreased. As before, adult longevity decreased

between 25° C and 30° C. Pupae completed development at all temperatures and

developmental time was inversely related to temperature (Tables 1-3).

Adults. — The results starting with colony reared adults at each test temperature

are similar to those starting with pupae: maximum female fecundity and fertility,

and male longevity at 25° C. Female longevity was greatest at 20° C (Table 2).

The preoviposition period ranged from 23.8 days at 20° C to 8.4 days at 30° C

(Table 3).

Cross Test Comparisons. — Female fecundity and fertility were significantly re¬

duced (P < 0.01) when pupae or adults were removed from the 25° C rearing

colony and placed at 20° C when compared to females reared at 20° C starting as

eggs or larvae. Adult survival at 30° C was significantly increased (P < 0.01) in

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 2. Effect of temperature on female fecundity and fertility, and adult longevity of Bactrocera

zonata.

Test

°c

Eggs per female

Percent egg hatch

Adult longevity (days) 3

Female Male

Egg to adult

177.62 [B]

53.33 [B]

78.94 [A]

62.26 [B]

215.93 [A]

81.67 [A]

76.14 [A]

70.33 [A]

—

4.70 [B]

3.77 [C]

Larvae to adult

175.58 [B]

57.00 [B]

70.08 [A]

61.56 [A]

195.23 [A]

82.00 [A]

59.83 [B]

45.80 [B]

—

3.10 [C]

2.97 [C]

Pupae to adult

—

19.33 [C]

17.33 [C]

111.53 [B]

48.33 [B]

57.03 [B]

49.8 [B]

202.7 [A]

81.30 [A]

72.80 [A]

62.7 [A]

—

16.70 [C]

12.60 [D]

—

8.60 [D]

6.37 [E]

Adult

—

12.30 [C]

9.80 [C]

80.82 [B]

34.33 [B]

76.67 [A]

62.63 [A]

172.27 [A]

89.67 [A]

67.6 [B]

66.10 [B]

—

11.50 [C]

10.40 [B]

—

5.03 [D]

4.30 [C]

a Means followed in square brackets by different capital letters within each test differ at P < 0.05;

n = 30 pairs of flies per replicate with three replicates conducted.

flies held at 25° C until they were pupae or adults compared to those reared at

30° C starting as eggs or larvae.

Holding the previous developmental stages at 25° C had no effect on the de¬

velopmental times or survival for B. zonata larvae or pupae held at 20° C or 30°

Table 3. Effect of temperature on duration of developmental stages of Bactrocera zonata that were

reared on artificial diet.

Stage duration (days) 3

Test

°c

Egg

Larvae

Pupae

Preoviposition

Egg to adult

2.90 [A]

—

1.79 [B]

13.5 [A]

18.7 [A]

1.02 [C]

6.1 [B]

11.6 [B]

1.02 [C]

5.4 [B]

6.2 [C]

Larvae to adult

12.2 [A]

21.4 [A]

6.2 [B]

11.5 [B]

5.8 [C]

8.3 [C]

Pupae to adult

30.0 [A]

18.0 [B]

10.3 [C]

7.4 [D]

4.1 [E]

Adult

never

23.8 [A]

14.4 [B]

8.4 [C]

never

a Means followed in square brackets by different capital letters within each test differ at P < 0.05;

n = 100 individuals per replicate, with three replicates conducted.

1993 QURESHI ET AL.: DEVELOPMENT OF BACTROCERA ZONATA

C (Table 1). This indicates that rearing the flies in colony at 25° C for the duration

of this experiment caused no acclimation of the insects.

Discussion

Rearing temperature had a significant effect on the rate of B. zonata develop¬

ment. Like other fruit flies (Messenger & Flitters 1958, Pritchard 1978, Saeki et

al. 1980, Fletcher & Kapatos 1981, Okumura et al. 1981), development is sigmoid

up to a maximum of 26° C to 30° C and decreases thereafter. Although other

factors including fruit moisture, ripeness, and variety, and larval crowding (Smith

1977, Tsitsipis & Abatzis 1980, Ibrahim & Rahman 1982, Carey et al. 1985)

influence fruit fly developmental rate, temperature is the key factor in the field

(Fletcher & Comins 1985).

Our data indicate that B. zonata can complete three to nine generations per

year in the various parts of its range. This estimate compares favorably with other

polyphagous fruit flies including B. dorsalis and B. tryoni (Froggatt) which have

three to eight generations per year in various parts of their ranges (Saeki et al.

1980, Meats 1981).

Our results provide useful information for better handling of B. zonata in the

laboratory. Mass rearing of fruit flies requires optimizing the rearing conditions

for each stage to maximize turnover of production and quality of insect produced.

Our data indicate that the optimum temperature for larval (25° C to 27° C) and

pupal (20° C to 25° C) rearing are different because, aside from faster development,

other parameters such as percent pupation, complete adult emergence from the

puparia, and larval and pupal survival should also be considered. Temperature

limits in a mass rearing system should be kept lower than optimum to avoid

accidental overheating either from malfunctioning cooling systems or the build¬

up of metabolic heat.

Acknowledgment

This work was supported by a California Department of Food and Agriculture

Research contract to the University of California.

Literature Cited

Carey, J. R., E. J. Harris & D. O. Mclnnis. 1985. Demography of a native strain of the melon fly,

Dacus cucurbitae Coq. from Hawaii. Entomol. Exp. Appl., 38: 195-199.

Dowell, R. V. 1988. Exclusion, detection, and eradication of exotic fruit flies in California. In

AliNiazee, M. T. (ed.). Ecology and management of economically important fruit flies. Agric.

Exp. Stn., Oreg. State Univ., Spec. Rpt., 830.

Dowell, R. V. & R. Gill. 1989. Exotic invertebrates and their effects on California. Pan-Pacif.

Entomol., 65: 132-145.

Fletcher, B. S. & H. Comins. 1985. The development and use of a computer simulation model to

study the population dynamics of Dacus oleae and other fruit flies, pp. 561-575. In Atti XIV

Cong. Naz. Hal. Entomol.

Fletcher, B. S. & E. T. Kapatos. 1981. Dispersal of the olive fly, Dacus oleae during the summer

period on Corfu. Entomol. Exp. Appl., 29: 1-8.

Ibrahim, A. G. & M. D. A. Rahman. 1982. Laboratory studies on the effects of selected tropical

fruits on the larvae of Dacus dorsalis Hendel. Pertanika, 5: 90-94.

Kapoor, V. C. & M. L. Agarwal. 1983. Fruit flies and their increasing host plants in India, pp. 252-

267. In Cavalloro, R. (ed.). Fruit flies of economic importance. A. A. Balkema, Rotterdam.

Kapoor, V. C., D. E. Hardy, M. L. Agarwal & J. S. Grewal. 1980. Fruit fly (Diptera: Tephritidae)

systematics of the Indian subcontinent. Export India Pub., Jullundur, India.

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Meats, A. 1981. The bioclimatic potential of the Queensland fruit fly, Dacus tryoni in Australia.

Proc. Ecol. Soc. Aust., 11: 151-163.

Messenger, P. S. & N. E. Flitters. 1958. Effect of constant temperature environments on the egg

stage of three species of Hawaiian fruit flies. Ann. Entomol. Soc. Am., 51: 109-119.

Moore, I. 1960. A contribution to the ecology of the olive fly, Dacus oleae (Gmel.). Israel Agric.

Res. Sta., Spec. Bull., 26.

Nair, M. R. G. K. 1975. Insects and mites of crops in India. Indian Council Agric. Res., New Delhi.

Okumura, M., T. Ide & S. Takagi. 1981. Studies on the effect of temperature on the development

of the melon fly, Dacus cucurbitae Coq. Res. Bull. Plant Prot. Serv. Japan, 17: 51-56. [In

Japanese with English abstract]

Pritchard, G. 1978. The estimation of natality in a fruit infesting insect (Diptera: Tephritidae). Can.

J. Zool., 32: 353-361.

Saeki, S., M. Katayama & M. Okumura. 1980. Effect of temperature upon the development of the

oriental fruit fly and its possible distribution in the mainland of Japan. Res. Bull. Plant Prot.

Serv. Japan, 16: 73-76. [In Japanese with English abstract]

Smith, E. S. C. 1977. Studies on the biology and commodity control of the banana fly, Dacus musae

(Tryon), in Papua New Guinea. Papua New Guinea Agric. J., 28: 47-56.

Tassen, R. L., T. K. Palmer, K. S. Hagen, A. Cheng, G. Feliciano & T. L. Blough. 1983. Mediterranean

fruit fly life cycle estimates for the California eradication program, pp. 564-570. In Cavalloro,

R. (ed.). Fruit flies of economic importance. A. A. Balkema, Rotterdam.

Tsiropoulos, G. 1972. Storage temperatures for eggs and pupae of the olive fly. J. Econ. Entomol.

65:100-102.

Tsitsipis, J. A. & C. Abatzis. 1980. Relative humidity effects at 20°C on eggs of olive fly Dacus oleae

(Diptera: Tephritidae) reared on artificial diet. Entomol. Exp. Appl., 28: 92-99.

Received 21 April 1992; accepted 13 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 77-94, (1993)

BEE FAUNA ASSOCIATED WITH SHRUBS IN TWO

CALIFORNIA CHAPARRAL COMMUNITIES

Heidi E. M. Dobson 1

Department of Entomology, University of California,

Davis, California 95616

Abstract. — The bee faunas visiting spring-blooming shrubs in the chaparral of northern California

were compared between two localities having similar plant species but different climatic regimes.

Bees were collected from mid-March to mid-July during two consecutive years that were char¬

acterized by different rainfall. In the Inner Coast Ranges of Napa County, with a mediterranean

climate, 73 bee species from six families were recorded on 11 shrub species; Megachilidae was

the most species-rich family, followed by Andrenidae and Halictidae. Immediately inland from

the coast in Marin County, where the frequently cool, foggy conditions are unfavorable for many

solitary bees, the bee fauna had only half the number of species and a third the number of

individuals; there were very few Megachilidae and a relatively high abundance of bumble bees.

Of the 81 total species at both sites, close to one-third were shared between sites; the introduced

honey bee was ubiquitous. A greater number of species were collected during the year of normal

rainfall, most species were recorded in low abundance, and females comprised two-thirds of the

collected specimens. Shrubs of the genus Ceanothus attracted the greatest diversity of bees.

Comparison with other regional bee surveys shows the inland site here to be most typical of

other areas with chaparral.

Key Words.— Insecta, Apoidea, Hymenoptera, faunal survey, chaparral, pollination, California

Surveys of pollinators in different plant communities of California show the

chaparral community to have the largest diversity of bee species per area, as well

as comparatively high diversities of other flower-visiting insects (Moldenke 1976a).

Furthermore, these studies indicate that bees are the most species-rich group of

pollinators throughout California, with the exception of subalpine marsh mead¬

ows. Bees are typically most diverse in warm temperate xeric climates (Michener

1979). Within California, the southern deserts and mediterranean-climate regions

have the highest number of species, with up to three-fold more than alpine, Great

Basin, and immediate-coastal areas (Moldenke 1976a, 1979a). This concentration

in arid regions may be attributed, in part, to the generally high diversity of plants

blooming during the short flight season of bees, and to the tendency of most

solitary bees to nest in the ground, where risk of mortality from fungus attacks

is decreased in dry climates (Linsley 1958, Michener 1979). In the chaparral

community, bees are the most significant pollinators; in terms of abundance, they

outnumber all other flower-visiting insects except beetles, whose greatest impact

is, however, as flower herbivores (Moldenke 1976a).

The chaparral vegetation covers large areas of California and occurs inland from

the coast, mainly within the Coast Ranges and at low- to mid-elevations bordering

the Central Valley, especially on dry rocky slopes with thin soil (Munz & Keck

1959, Keeley & Keeley 1988). These regions are characterized by a prevailingly

mediterranean-type climate with hot dry summers and cool wet winters, but

chaparral may also extend into areas with more moderate climatic regimes. Chap-

1 Present address: Department of Biology, Whitman College, Walla Walla, Washington 99362.

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

arral is dominated by evergreen sclerophyllous, fire-adapted shrubs, which com¬

monly include Adenostoma fasciculatum Hooker & Amott (chamise), Ceanothus

spp., and Arctostaphylos spp. (manzanita); the herbaceous cover is generally sparse

except during the first years following fire (Hanes 1977, Keeley & Keeley 1988).

In mature chaparral, flowering shrubs comprise the major food source for bees,

although herbaceous plants growing in shrub openings or neighboring grassland

appear to play a role in maintaining populations of certain bee species (Dobson

1980). The principal blooming season follows the winter rains, with most shrub

species flowering between March and June (Moldenke 1979b). This corresponds

to the period in spring when both soil moisture is still plentiful and ambient

temperatures have increased to levels favorable for insect activity, but before the

hot, dry summer begins; this is also the time when most insects, including flower

visitors, reach peak numbers (Force 1990).

This paper compares the species composition and relative abundance of bees

collected on the flowers of spring-blooming shrubs in two chaparral sites in north¬

ern California. The sites were chosen for their ease of accessibility and generally

similar shrubby flora; they differed in climate, with the site closer to the coast

being cooler and subject to frequent fog. Data on the bee fauna were gathered for

two consecutive years characterized by sharply different amounts of rainfall. The

results here represent part of a broader study of the pollinator and flower-visiting

insect fauna associated with chaparral shrubs (Dobson 1980). In addition to in¬

creasing our understanding of insect-plant interactions in the chaparral, this study

had the goal of providing baseline data for future faunal surveys and to serve in

efforts to preserve the California chaparral community.

Methods and Materials

The study was carried out at two chaparral sites, 50 airline km apart, in northern

California. The first site was located in the Inner Coast Ranges of Napa County,

on the upper east-facing slope of Mt. Yeeder at 550 m elevation. The vegetation

consisted principally of mature impenetrable chaparral, interspersed with stands

of mixed evergreen forest, but within the study plot (approximately 200 m 2 ) the

chaparral was more open, having been cleared mechanically 4 years previously;

herbaceous plants were sparse. The second site was situated in the Outer Coast

Ranges in Marin County, at the foot of Pine Mountain at 335 m elevation, facing

south over Alpine Lake. Due to the closer proximity of the ocean (within 12

airline km), the spring-summer climate is cooler and windier than on Mt. Veeder,

with frequent fog, especially in the mornings. The study plot, of similar size as

the previous, was in an area where the strongly serpentine character of the soil

yielded an open plant cover comprised of low-growing shrubs, which included

serpentine-endemic species.

Bees visiting the flowering shrubs were censused at each site 1 day per week

during the spring-summer months, from mid-March to mid-July in 1977 and

1978, using sweep-net collection methods. Collecting was concentrated on selected

shrubs of each species, which were sampled in succession over 30 min periods

every 2-3 h, from 08:30 h to 16:30 h, thus spanning the daytime hours of bee

activity. Hourly recordings of ambient temperature were taken during each sam¬

pling day in 1978. Based on the collected specimens, bee faunas were compared

between sites with respect to the numbers and kinds of species, relative abun-

1993

DOBSON: CHAPARRAL BEES

dances, sex ratios, and Shannon-Wiener diversity indexes of individual families,

temporal activities, and shrub associations. Some species, particularly fast-flying

bees (e.g., large Anthophoridae), were difficult to collect and, therefore, are un¬

derrepresented in the samples. The introduced honey bee, which was very com¬

mon on certain shrubs, was not collected in proportion to its abundance and was

censused mainly for its presence. Bee specimens were identified by specialists and

vouchers deposited in the R. M. Bohart Museum of Entomology, University of

California, Davis.

Results

Habitat Resources.— During the study a total of 13 shrub species from seven

families bloomed at the two sites: 11 at Mt. Yeeder and eight at Pine Mountain;

six of the species occurred at both sites. Following the nomenclature of Munz &

Keck (1959), shrubs common to the sites were Eriodictyon californicum (Hooker

& Amott) Torrey (Hydrophyllaceae), Pickeringia montana Nuttall (Leguminosae),

Rhamnus californica Eschscholtz (Rhamnaceae), Adenostoma fasciculatum and

Heteromeles arbutifolia M. Roemer (Rosaceae), and Mimulus ( Diplacus ) auran-

tiacus Curtis (Scrophulariaceae); only at Mt. Veeder: Arctostaphylos viscida Parry

(Ericaceae), Dendromecon rigida Bentham (Papaveraceae), Ceanothus foliosus

Parry, C. parryi Trelease, and C. sonomensis J. T. Howell (Rhamnaceae); and

only at Pine Mountain: Arctostaphylos pungens var. montana (Eastwood) Munz

and Ceanothus jepsonii Greene. With the exception of Dendromecon, all genera

were represented at both sites. Thus, any taxonomic differences between sites were

at the species level.

Blooming phenologies of the shrubs were generally similar both years, but flower

density was less in 1977. This was especially marked fori?, californica, P. montana,

and A. fasciculatum (produced no flowers); C. parryi on Mt. Veeder was unusual

in producing a denser bloom in 1977. The two study years differed markedly in

rainfall, and this was most pronounced in the more inland site on Mt. Yeeder.

During 1977, which was the second of two consecutive years with severe drought,

precipitation was several fold less than in 1978, which received slightly above

normal rainfall. For each weather year (1 Jul-30 Jun), rainfall at Mt. Veeder was

32.94 cm (1977) and 117.07 cm (1978), with an average over 33 years of 82.96

cm (data from Oakville, Napa Co., National Weather Service 1948-1981); at Pine

Mt., rainfall was 56.74 cm (1977) and 170.21 cm (1978), with an average over

113 years of 131.47 cm (data from Lake Lagunitas, Marin Co.; Roxon 1992).

Bee Species. — A total of 81 bee species, representing six families, were collected

on the 13 shrubs at the two sites (Appendix 1). Mt. Veeder had 73 species, and

thus twice as many as Pine Mountain, with only 36 species (Table 1). With the

exception of Halictidae, which had an equal number of species at both sites,

species numbers within each family were greater at Mt. Veeder; this was most

pronounced in Megachilidae, where differences between sites reached ten-fold.

Approximately one-third of the species were collected at both sites (Table 1

and Appendix 1). This shared bee fauna constituted a high proportion (78%) of

the species at Pine Mountain, but only a third (38%) of those at Mt. Veeder;

Halictidae, which was the most species-rich family at Pine Mountain, contributed

the largest number (10 of 28 species). Of the 53 species collected exclusively at

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Number of bee species collected at each site and number shared by (common to) both

sites.

Mt. Veeder

Pine Mtn.

Family

Only

1977

Only

1978

Both

1977/1978

Total

1977

+ 1978

Only

1977

Only

1978

Both

1977/1978

Total

1977

+ 1978

Shared

Andrenidae

Anthophoridae

Apidae

Colletidae

Halictidae

Megachilidae

Sum

8.4

38.4

53.4

100.0

19.4

44.4

36.1

100.0

one site, 45 were at Mt. Veeder and, among these, close to 50% were Megachilidae

and 20% Andrenidae.

A larger number of bee species were collected in 1978, when rainfall was normal,

than in 1977, a year of drought (Table 1). Both sites showed relative increases of

close to 50% from 1977 to 1978. Species exclusive to 1978 included a large

proportion of the small and mainly late-spring active bees (e.g., Colletidae, Halicti-

dae, and Ceratina in Anthophoridae). The majority of species collected in 1977

were recorded both years. These more constant bees, which represented the most

stable component of the fauna, comprised approximately half the species at Mt.

Veeder and a third of those at Pine Mountain.

Bee Relative Abundance. — During the two years, 799 bee specimens were col¬

lected at Mt. Veeder and 205 at Pine Mountain (Table 2). Most species were low

in abundance (Appendix 1). Based on apparent breaks in the numbers of species

distributed in function of their abundance, 54% of species at Mt. Veeder can be

classified as rare (1-4 specimens each), 26% occasional (5-15 specimens), 14%

common (20-32 specimens), and 6% abundant (48-96 specimens). Abundant

species consisted of Andrena chlorura Cockerell and A. vandykei Cockerell (An¬

drenidae), Bombus edwardsii Cresson (Apidae), and Hylaeus polifolii (Cockerell)

(Colletidae). The pattern at Pine Mountain was very similar, with 57% of species

rare (1-2 specimens), 23% occasional (3-6 specimens), 14% common (8-14 spec¬

imens), and 6% abundant (21-37 specimens). The latter included Panurginus

nigrellus Crawford (Andrenidae) and H. polifolii.

Table 2. Bee abundance (number of specimens collected) at each site over both years.

Family

Mt. Veeder

Pine Mtn.

Total

% 6

Total

% 3

Andrenidae

219

245

10.6

57.1

Anthophoridae

35.1

0.0

Apidae

101

143

29.4

9.1

Colletidae

113

153

73.9

72.5

Halictidae

7.8

40.0

Megachilidae

111

31.5

50.0

Total

556

243

799

30.4

118

205

42.4

1993

DOBSON: CHAPARRAL BEES

Table 3. Representation of each family in terms of species and specimen numbers, and family

diversity index H'.

Family

Mt. Veeder

Pine Mtn.

% total

species

% total

specimens

H'“

% total

species

% total

specimens

H' a

Andrenidae

20.5

30.7

1.88

25.0

20.5

1.60

Anthophoridae

11.0

7.1

1.63

8.3

2.4

1.05

Apidae

8.2

17.9

0.92 b

11.1

26.8

0.99 b

Colletidae

12.3

19.1

1.71

13.9

24.9

0.88

Halictidae

17.8

11.3

2.06

36.1

24.4

2.18

Megachilidae

30.1

13.9

2.77

5.6

1.0

0.69

a Shannon-Wiener diversity index, where H' = -Zp;ln p;, and pj = proportion of total specimens

in a family that belong to the ith species (Whittaker 1972).

b Excluding the introduced honey bee, Apis mellifera.

The proportion of males collected varied among families and between sites

(Table 2). Colletidae had an exceptionally high percentage of males (over 70%)

at both sites, whereas most other families had a marked predominance of females.

In Andrenidae and Halictidae, males and females tended to be more equally

represented at Pine Mountain.

Bee Faunal Composition. — In terms of species numbers, each site was domi¬

nated by a single family (Table 3). Megachilidae (with 30% of the species) were

dominant at Mt. Yeeder and Halictidae (36%) at Pine Mountain. Figures for other

families were generally similar between sites, with Andrenidae occupying second

place. Pine Mountain had a striking paucity of Megachilidae (5.6%).

With respect to relative abundance (Table 3), Andrenidae were clearly the most

abundant bees at Mt. Yeeder, whereas no family predominated at Pine Mountain.

Anthophoridae were few at both sites. Overall, the sites differed in the compar¬

atively high relative abundance of Andrenidae at Mt. Veeder and the low abun¬

dance of Megachilidae at Pine Mountain.

The Shannon-Wiener diversity index of each family, which is based on both

the number of species and the relative abundance of each species (Whittaker

1972), provides a measure of how equitably the species are represented within

each site (Table 3). Megachilidae had the highest diversity at Mt. Veeder, followed

by Halictidae, whereas at Pine Mountain Halictidae was highest. Index values at

Mt. Veeder clearly exceeded those at Pine Mountain for Megachilidae, Colletidae,

and Anthophoridae.

Temporal Activity of Bees. — Daily activity levels, based on the number of spec¬

imens collected at bihourly intervals, were generally uniform among families and

between sexes. At Mt. Veeder, bee activity showed a normal distribution, with a

maximum around midday. This corresponded with, or slightly preceded, the time

of highest daily ambient temperature between 13:00 and 15:00 h. Diverging ac¬

tivity patterns were evident in four cases: (1) female Megachilidae, with a generally

high activity over the morning hours; (2) female Andrenidae, with peak activity

during mid-morning; (3) male Colletidae, with maximum activity extending broadly

from mid-morning to mid-afternoon; and (4) male Apidae ( Bombus ) and Antho¬

phoridae (excluding Ceratina), with a bimodal activity curve showing a small

peak in early morning and a principal peak at midday.

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Seasonal activity patterns of bee families, measured by the number of species

collected over the course of the study, were in general similar at the two sites. As

exemplified by Mt. Yeeder (Fig. 1), Andrenidae flew almost exclusively during

the early part of the spring, Megachilidae reached peak activity during the middle

period, and Colletidae, with initially very low activity, increased across the season;

Halictidae, Apidae, and Anthophoridae maintained relatively constant levels

throughout the study. Considering all families together, the total number of species

was quite uniform and showed only a moderate peak in early spring, associated

primarily with the blooming of Ceanothus, and a smaller one at the end of the

season, on Heteromeles.

Bee-shrub Associations. — A list of bee species collected on each shrub genus at

each site is provided in Appendix 1; bee-shrub associations at Mt. Veeder are

broken down by bee family in Fig. 1. The number of bee species per shrub genus

ranged from 4-33 at Mt. Veeder and 2-16 at Pine Mountain. At Mt. Veeder,

Ceanothus (33 species) received the greatest number, followed by Heteromeles

(27 species), Eriodictyon and Pickeringia (each 23 species); Dendromecon (four

species), which is nectarless, received the fewest. A major contrast between sites

was the paucity of bees on Mimulus and Pickeringia at Pine Mountain, whereas

at Mt. Veeder these shrubs attracted numerous species, especially Megachilidae.

At Mt. Veeder each shrub genus was visited by at least three of the six bee families;

all families were represented on Ceanothus and Eriodictyon.

Bee-shrub associations showed greater diversity at Mt. Veeder. Bees recorded

at both sites generally visited more shrub taxa at Mt. Veeder and most bee-shrub

associations at Pine Mountain were likewise observed at Mt. Veeder. At the bee

family level, Halictidae and Apidae showed the broadest associations, which

spanned all shrub genera, and Andrenidae exhibited the most restricted visitation.

At the bee species level, Andrenidae tended to visit principally Arctostaphylos

and Ceanothus shrubs. The majority of species in other families showed more

generalist foraging patterns, with several host shrubs each. Rower and pollen

specificity at Mt. Veeder are discussed in greater detail in Dobson (1980).

The Introduced Honey Bee. — Honey bees were frequent at both sites and foraged

throughout the day from early morning to late afternoon, utilizing floral resources

over longer daily periods than most native bees except Bombus. At Mt. Veeder,

they visited all shrubs except Mimulus ; they were the most abundant bees on

Arctostaphylos and the tree Arbutus menziesii Pursh (madrone, Ericaceae), both

of which bloomed in early spring during the major population growth of honey

bee colonies, and on Rhamnus and Heteromeles, which were the last nectar¬

providing shrubs to bloom. At Pine Mountain, honey bees accounted for the

majority of visitors on five of the seven shrub species and seemed to occupy a

foraging niche generally similar to that of bumble bees.

Although no remarkable interferences in foraging were observed among any of

the native bees, several instances of negative interactions were recorded between

honey bees and native bees, especially at Mt. Veeder where solitary bees were

most abundant. During these encounters, which occurred mainly on Rhamnus

and Heteromeles, honey bees either actively chased small bees away from flowers

or caused them to fly off upon landing on the same flower or inflorescence.

Individual shrubs heavily frequented by honey bees appeared to have distinctly

1993

DOBSON: CHAPARRAL BEES

Mt. Veeder

Number of bee species

Shrub genera

1 I Megachilidae 011111111 Halictidae HH Colletidae

llM Apidae Anthophoridae HE Andrenidae

Figure 1. Number of bee species in each family that were collected on the different shrub genera,

Mt. Yeeder, 1977 and 1978. Shrubs are arranged according to the seasonal chronology of their peak

blooming periods.

fewer solitary bees compared to other shrubs, but no count data were collected

to verify this impression.

Discussion

The two chaparral sites were found to have bee faunas that differed sharply in

both numbers of species and abundance, even though the shrub floras were similar.

With twice as many species of bees and over three-fold more bee specimens, the

Mt. Veeder site, situated in the warm and dry Inner Coast Ranges, had a much

more diverse bee fauna, as is also reflected in the higher diversity indexes within

its bee families. The cooler and more coastal climatic conditions (frequent fog

and winds) at the Pine Mountain site, located just inland from the coast, appeared

to be a major factor limiting its bee fauna, thereby overriding intersite similarities

in the composition of bee host-plants. Likewise, the presence in northern Cali¬

fornia of comparatively few flower-visiting insects on the immediate coast at

Point Reyes, compared to a chaparral site at Jasper Ridge, has also been attributed

to the restrictions imposed by the foggy, cool, and windy coastal climate (Moldenke

1975).

Parallel decreases in bee fauna associated with proximity to the coast have been

documented in other areas. In California, reductions of 50% in bee species, as

well as in total pollinator diversity, may occur in coastal communities compared

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

to adjacent chaparral (Moldenke 1976a), and differences of the same magnitude

have been recorded between vegetationally similar (but floristically different) coastal

and inland sites in scrubby mediterranean-climate areas of southern Spain (Her¬

rera 1988) and Chile (Moldenke 1979b, c). These changes in bee species are,

however, not surprising, given the general tendency of bee numbers to increase

as one moves into comparatively warmer, more xeric habitats (Linsley 1958,

Michener 1979, Dylewska 1988, Armbruster & Guinn 1989).

Moldenke’s (1976a) observations that the pollinator fauna of northern coastal

scrub shifts to a depauperate chaparral fauna inland of the immediate coast are

corroborated here, where almost 80% of the species at Pine Mountain were also

found at Mt. Veeder. Nevertheless, of the total species at Mt. Veeder, only 23%

included the chaparral community among their list of characteristic habitats (Mol¬

denke & Neff 1974a); the majority belonged to Andrenidae and Megachilidae,

the two most species-rich families at the site. The corresponding figure at Pine

Mountain was 22%, with the species distributed among several families. According

to geographic and habitat distributions listed for 66 of the 81 species at the two

sites (Moldenke & Neff 1974a), 61 species are wide-ranging and occur mainly in

montane regions of both northern and southern California, and five are principally

southern Californian species.

In terms of bee faunal compositions, the most striking contrast between sites

was the high percentage of Megachilidae species at Mt. Veeder, which supports

reports that this family is generally well represented in the scrubby vegetations

of California but is less prevalent in other habitats, including coastal areas (Mol¬

denke 1976a). A second contrast was the high percentage of Halictidae at Pine

Mountain. Comparison with bee faunas in other chaparral and coastal commu¬

nities in California (Table 4) shows that both sites resemble others in their per¬

centage of species in Andrenidae (high), but are distinctive in having figures that

are higher for Colletidae and lower for Anthophoridae. These differences may

arise partly from the study being restricted in time (i.e., to spring-summer months)

and in habitat (i.e., to shrubby plants). Similarly affected was the total number

of recorded species: at Mt. Veeder this was very low compared to other chaparral

sites; at Pine Mountain it was somewhat lower compared to the other coastal

areas. Discrepancies specifically in the number of Anthophoridae may result from

the under-collection of fast-flying species as well as the lack of revisionary studies

of Nomada (resulting in many undescribed species) which, while accounting for

the largest proportion of Anthophoridae species in Moldenke (1976b), were col¬

lected in only low numbers here. Comparisons in the Apidae, Halictidae, and

Megachilidae, however, suggest that Mt. Veeder is more typical of chaparral and

Pine Mountain of coastal habitats. Indeed, Mt. Veeder resembled the chaparral

regions in its unusually high percentage of Megachilidae (around 30%) and some¬

what low percentage of Halictidae (under 20%), whereas Pine Mountain displayed

in extreme the coastal sites’ opposite trends and a moderate tendency for higher

proportions of Apidae.

Relative abundance of each family did not closely follow patterns in species

numbers, and the greatest deviations occurred at Mt. Veeder in Apidae, with few

species but high abundances, and Megachilidae, with many species comprised of

few individuals each. The distribution of specimen numbers across the species

was very similar at the two sites; the majority of species (80%) had low relative

1993

DOBSON: CHAPARRAL BEES

Table 4. Family representations of bee faunas (% total species) at various localities with chaparral

or coastal vegetation in California.

Chaparral vegetation

- Mixed Coastal vegetation

Family

Mt.

Veeder

Pine

Mtn.

coast

range- 1

Mather 1

Echo

Valley c

Japatul

Valley* 1

Channel

Islands*

coast r

Bodega 8

Hum¬

boldt 11

coast'

Andrenidae

20.5

25.0

18.3

21.5

20.1

18.5

20.3

20.4

17.0

9.3

28.4

Anthophoridae

11.0

8.3

28.1

22.2

28.4

20.5

32.0

25.3

25.5

11.6

32.1

Apidae

8.2

11.1

2.9

4.2

1.2

1.3

4.6

6.2

17.0

25.6

2.4

Colletidae

12.3

13.9

4.2

7.6

5.3

2.0

1.3

6.2

4.3

7.0

1.2

Halictidae

17.8

36.1

16.2

15.3

19.5

19.2

24.8

26.5

21.3

23.3

22.2

Megachilidae

30.1

5.6

30.2

29.2

24.9

37.7

17.0

14.8

14.9

23.3

11.1

Melittidae

0.6

0.7

0.6

2.4

No. species

377

144

169

151

153

162

a Jasper Ridge, San Mateo Co. (Moldenke 1976a).

b Sierra Nevada foothills, Tuolumne Co. (Moldenke & Nelf 1974b).

c San Diego Co. (Moldenke & Nelf 1974b).

d Post-fire (mainly annual flora), San Diego Co. (Moldenke & Neff 1974b).

e Mainly chaparral and coastal scrub/prairie (Rust et al. 1985).

f Coastal scrub, Point Reyes, Marin Co. and Pescadero, San Mateo Co. (Moldenke 1976a).

g Dunes and prairie, Sonoma Co. (Thorp & Gordon 1992).

h Dunes, Humboldt Co. (Thorp & Gordon 1992).

■ Coastal scrub, Torrey Pines, San Diego Co. (Moldenke & Neff 1974b).

abundances, and only 6% were exceptionally numerous. The patterns corroborate

general trends of plant and animal surveys, in which species-abundance curves

typically show logarithmic distributions (Preston 1948, Tepedino & Stanton 1981).

Bees were most numerous, in both species and individuals, during the year of

normal rainfall, when plant bloom was denser and all shrub species flowered. The

substantial increases in species numbers that occurred at both sites from the year

of drought (1977) to the year of normal rainfall (1978), amounting to almost half

of the total species recorded, indicates that bee diversity during a given year is

not simply a function of the previous year’s bee fauna. Indeed, it suggests that

some bee species are parsivoltine, in which individuals of a single species require

different numbers of years to complete development or emerge from the nest.

Parsivoltinism has been documented in several bees, especially Megachilidae, and

studies of Osmia species suggest that this polymorphism in emergence time is

genetically controlled (Torchio & Tepedino 1982). However, it cannot be excluded

that in other cases emergence may be cued to rainfall patterns and that during

unfavorable years bees may remain dormant in their nests until a more favorable

season (Linsley 1958). This may apply to Mt. Veeder, where most of the bees

collected exclusively during the year of normal rainfall were species that fly in

mid-spring to summer when any water shortage effects might critically restrict

bee activity. The triggering of bee emergence by moisture levels has been proposed

especially in relation to desert bees that were observed to fly only when water was

sufficient for their primarily annual host plants to germinate and bloom (e.g.,

Linsley 1978).

The few bee species recorded exclusively during the drought year may represent

bees that extended their foraging ranges into neighboring habitats or onto alternate

host plants (i.e., chaparral shrubs) to supplement the decreased availability of

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

their usual food plants. The yearly variation in floral resources observed in this

study does not appear to be very unusual in plant communities (e.g., Rotenberry

1990, Tepedino & Stanton 1980). Furthermore, the corresponding changes in the

bee fauna lend support to Tepedino & Stanton’s (1981) contention that a large

proportion of the occasional bees within a fauna may be opportunistic fugitives

that respond to the spatiotemporal unpredictability of floral resources by dis¬

persing among patchily distributed food sources. Given the comparatively great

variance in annual rainfall, common occurrence of drought, and year-to-year

variation in flower production within the chaparral (Keeley & Keeley 1988), the

differences in bee faunal compositions obtained over the 2 years here could be

viewed as typical of chaparral communities.

The differing composition and abundance of bee species at the two sites probably

stemmed primarily from the influence of climatic conditions on bee activity,

although availability of nesting sites and density of host-plant bloom may have

also played a role. The warmer, drier, and more constant spring-summer weather

at Mt. Veeder provided more hours during the day and days during the season

that were favorable for bee activity than at Pine Mountain and thereby allowed

for a larger number of solitary bees. Most of the species collected exclusively at

Mt. Veeder were small-bodied or metallic-colored bees (e.g., Hylaeus, Osmia,

Ceratina ), which generally require higher ambient temperatures for flight than do

larger-sized bees (Stone & Willmer 1989). Unsurprisingly, in the changing climate

at Pine Mountain the abundance and diversity of bees on the shrubs fluctuated

often hourly in relation to the weather. During the frequent, cool periods of fog

and winds, activity decreased sharply and only honey bees and bumble bees

continued to forage. These large hairy bees, particularly Bombus, can generate

and maintain higher body temperatures under adverse ambient conditions (Hein¬

rich 1979, Stone & Willmer 1989) and were the most abundant bees at this site.

In addition, the cool moist climate at Pine Mountain may have limited the survival

of larvae in many bee species by increasing the susceptibility of nest provisions

to mold and by slowing bee development, thereby lengthening the mold-sensitive

period (Linsley 1958).

The tendency for most bees to reach peak numbers on the shrubs around midday

may reflect primarily their need to restrict their flower-visiting activity to daytime

hours when temperature and insolation are appropriately high (Linsley 1958,

1978; Kapyla 1974; Willmer 1983) and secondarily the temporal pattern of nectar

and pollen availability in the flowers. Depletion of food rewards was probably

the main cause behind the sharp decrease in bees after early afternoon. The

unimodal pattern of daily activity was strongest among the smaller bees; in pro¬

gressively larger and more hairy bees, this pattern became less pronounced and

eventually bimodal {Bombus and large Anthophoridae). Similar observations of

bees visiting Lavendula were shown to relate to differences in body size and were

correlated with the bees’ differing temperature requirements for flight and nectar-

water needs (Herrera 1990). It has certainly been repeatedly noted that the com¬

position of bee species at a flower source changes during the day, with the most

energetically demanding bees arriving first (Roubik 1989). On a seasonal level,

in mediterranean Israel the body sizes of bees are reported to correlate negatively

with the seasonal increase in air temperature (Shmida & Dukas 1990), but such

trends were not evident in the present study with the possible exception of Hylaeus,

1993

DOBSON: CHAPARRAL BEES

which, unlike other small-sized bee groups, showed a general increase in numbers

of species over the course of the study.

The relatively open vegetation of both shrubs and trees in the area at Pine

Mountain contrasted with the more dense and heterogeneous woody vegetation

at Mt. Veeder, and although availability of nesting locations for ground-nesting

bees was probably comparable at the two sites, conditions for twig- and cavity¬

nesting bees may have been more limiting at Pine Mountain. Potentially vulner¬

able bees included Megachilidae, as well as wood-nesting species in Anthophoridae

(Ceratina and Xylocopa) and Colletidae ( Hylaeus ) (Stephen et al. 1969). However,

even in these cases, climate may have been the most restricting factor (P. F.

Torchio, personal communication).

Flowering shrubs were the principal food source for the bees collected at both

sites, based on field observations and on analysis of female pollen loads, although

some bees at Mt. Veeder did visit other plants in low frequency (Dobson 1980).

The shrub floras were similar between sites, and differed mainly in their respective

species of Arctostaphylos and Ceanothus, making it unlikely that shrub compo¬

sition was a major determinant of the sites’ different bee faunas. However, shrub

cover and consequently food density, which has been shown to influence levels

of bee foraging activity (Moldenke 1975, Ginsberg 1983, Sih & Baltus 1987), was

less at Pine Mountain and probably contributed to the lower abundance of bees.

The effect of shrub cover on bee species richness is less clear, but the marked

increases in bee species during 1978 when shrub bloom was denser (particularly

at Mt. Veeder) suggests that it too may have been a factor in the disparate number

of bee species between sites.

The diversity of bees visiting the different shrubs underscores the importance

of all shrub species in providing food for the resident bees. In turn, most chaparral

shrub species are self-incompatible and depend upon insects for pollination (Kee-

ley & Keeley 1988). Each shrub was visited by a distinctive spectrum of bee

species from different families. Ceanothus species and H. arhutifolia, covering the

beginning and end of the spring season respectively, attracted the greatest diversity.

Both genera have bowl-shaped flowers where the nectar and pollen are easily

accessible to a variety of insects. Curiously, A. fasciculatum, which has small

bowl-shaped flowers and is the most common shrub in the California chaparral,

received very low visitation. These patterns are not, however, consistent across

chaparral sites in California (Moldenke & Neff 1974c; A. R. Moldenke, personal

communication). At some locations, high bee diversities have been observed on

additional shrubs, including Arctostaphylos species, which were not fully sampled

in the present study; and although the paucity of bees on A. fasciculatum corrob¬

orates observations in other northern California sites (i.e., at Jasper Ridge and

Mather), in certain areas, particularly southern California, bee diversity may reach

very high levels. Ceanothus species, however, number regularly among the chap¬

arral shrubs attracting the greatest diversity of bees.

Certain bee families showed definite seasonal patterns in their numbers of

species and were consequently more frequent visitors on some shrubs than on

others, although shrub-choice was undoubtedly also influenced by accessibility

and quantity of food rewards. Thus, the early-season Andrenidae visited almost

exclusively Arctostaphylos and Ceanothus, as reported in other chaparral areas

(Moldenke & Neff 1974b), whereas Megachilidae, which reached peak numbers

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

at mid-season and are relatively long-tongued, foraged mainly on Eriodictyon,

Mimulus, and Pickeringia.

Reasons behind the differing proportions of male bees at Pine Mountain com¬

pared to Mt. Veeder are not clear, although sex ratios can vary considerably both

inter- and intraspecifically (Stephen et al. 1969, Michener 1974, Roubik 1989).

One factor possibly involved is the phenomenon of protandry, in which males

emerge up to a week or more prior to females (and females generally outlive

males). Although Linsley (1958) points out that some reports of protandry may

in fact reflect the earlier activity of males on flowers rather than any actual earlier

emergence, protandry appears to be prevalent in most families of bees except

Halictidae and Apidae (social species), which tend to produce males at the end

of the season (Robertson 1918, 1930). The remarkably low proportion of male

Andrenidae at Mt. Veeder may thus have resulted from the study being initiated

after the emergence of males but during the peak activity time of females. Indeed,

flower visitors on the early-blooming Arctostaphylos shrubs, which males appeared

to use as their principal food source, were not sampled throughout their entire

bloom period. At Pine Mountain, where the spring season was a little later, the

Arctostaphylos bloom was fully included in the study and the proportion of An¬

drenidae males reached much higher levels, close to 50%. In the case of bumble

bees, however, it is the factor of early-season nest establishment that underlies

the higher proportion of Bombus males at Mt. Veeder, most of which were B.

edwardsii. This species, which was poorly represented at Pine Mountain, as well

as B. vosnesenskii may establish nests in winter and produce males in early spring

(Linsley 1944, Thorp et al. 1983).

Besides timing of flight activity, several other factors may have influenced the

variation in sex ratios of collected bees, both within and between sites. First,

males and females may differ in the flowers they visit and thus in their tendency

to frequent shrubby species. Second, species-specific mating strategies and the

associated sites for mate location (e.g., at food sources, near nests, or elsewhere)

may result in differing abundances of males and females on the blooming shrubs.

Finally, males and females may vary in their wariness of any disturbance created

by the collector near the flowers (D. M. Gordon, personal communication) and

in the ease with which they are collected; these last factors may also create a bias

in the relative abundances of species based on collection data.

Observations of negative interactions between honey bees and solitary bees on

selected shrubs suggest that honey bees may substantially influence the foraging

activities of native chaparral bees and that they may be competing with them for

floral resources. The aggressive chasing away of smaller bees by honey bees was

similar to that reported in other bees (e.g., Frankie 1976) and did not appear to

reach the high levels of aggression described in eusocial bees (Roubik 1989). The

less aggressive displacement of solitary bees through their avoidance of honey

bees landing on their flowers may be a relatively common behavior in encounters

involving social bees of differing size or aggressivity (Johnson & Hubbell 1975,

Morse 1977, Roubik 1989). Although effects of honey bees are difficult to quantify,

data gathered by Schaffer et al. (1983) suggest that honey bees compete with native

bees (including bumble bees) by reducing the available nectar and evidence from

other studies imply that they can have a major impact on the population dynamics

and foraging activities of solitary bees (Eickwort & Ginsberg 1980, Ginsberg 1983).

1993

DOBSON: CHAPARRAL BEES

The present study points to the variation in bee faunas that can occur in similar

plant communities lying within short distances of each other and to the apparently

strong influence that climatic conditions may have in shaping bee diversity and

abundance. Given the compositional differences in bee faunas between the 2 years,

extension of the study over a broader seasonal span would provide further insight

in the population dynamics of native bees in these chaparral areas. In addition

to contributing to our understanding of chaparral insects (Force 1990), the data

herein could serve as a baseline for future sampling of chaparral bee faunas. From

the perspective of biological conservation, insect faunal monitoring is of prime

importance if we wish to evaluate any changes in a community incurred from

habitat (vegetation) changes, human disturbance, or introduced species. Yet, in¬

sects have been generally underrepresented in biotic inventories and local insect

surveys are wanting (Disney 1986, Wilson 1987). The paucity of attention given

to native bees, which are important pollinators of indigenous plants and thus key

components of communities, needs to be redressed (Osborne et al. 1991). With

this goal in mind, the information here could assist in the effective protection and

preservation of the California chaparral and its associated insect fauna.

Acknowledgments

I sincerely thank the following systematists who kindly identified bee specimens:

R. W. Brooks (various groups), H. Y. Daly ( Ceratina ), G. C. Eickwort (Halictidae),

G. Hackwell (Panurginus), W. E. LaBerge ( Andrena ), R. W. Rust ( Osmia ), R. R.

Snelling ( Hylaeus ), and R. W. Thorp ( Bombus, Megachilidae). I also thank Bob

Brooks, Robbin Thorp, and Dan Holmes for encouragement during the project,

Carolyn Dobson and Dennis Hall for permission to conduct research on their Mt.

Veeder property, and Andy Moldenke, Phil Torchio, Dan Holmes and Barry

Hecht for providing useful data sources for the manuscript. Finally, I gratefully

appreciate the stimulating discussions, critical input, and constructive advice that

were given during manuscript preparation by Robbin Thorp, Dave Gordon, Len¬

nart Agren, and Andy Moldenke.

This study represents a portion of a thesis submitted in partial fulfillment of

the requirement for the Masters degree in Entomology at the University of Cal¬

ifornia, Davis.

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mealybugs of the California Channel Islands (Hymenoptera, Homoptera). pp. 29-51. In Menke,

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first symposium. Kimberly Press, Goleta, California.

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Appendix 1. Bee species collected on the flowers of chaparral shrubs at the Mt. Veeder (V) and Pine Mountain (P) sites, 1977 and 1978, with total number of

specimens collected (males and females).

Host-shrub genera 2

No. bees

Bee species

Arct

Cean

Dend

Erio Mimu Pick

Rham Aden Hete

ANDRENIDAE

Andrena angustitarsata Yiereck

lie

Andrena astragali Yiereck & Cockerell

—

Andrena auricoma Smith

—

Andrena candidiformis Viereck & Cockerell

27C

Andrena chlorogaster Viereck

—

Andrena chlorura Cockerell

49C

Andrena crist at a Viereck

—

Andrena fuscicauda (Viereck)

Andrena obscuripostica Viereck

—

Andrena orthocarpi Timberlake

—

Andrena prolixa LaBerge

Andrena salicifloris Cockerell

—

Andrena transnigra Viereck

—

Andrena vandykei Cockerell

96C

Andrena w-scripta Viereck

IOC

—

Panurginus atriceps (Cresson)

28C

—

Panurginus gracilis Michener

—

Panurginus nigrellus Crawford

—

21B

ANTHOPHORIDAE

Anthophora pacifica Cresson

—

Anthophora urbana Cresson

—

Ceratina acantha Provancher

V V

13C

—

Ceratina arizonensis Cockerell

—

Ceratina nanula Cockerell

—

Ceratina punctigena Cockerell

—

Emphoropsis depressa (Fowler)

Nomada undet.

20C

Xylocopa tabaniformis var orpifex (Smith)

V V

IOC

—

THE PAN-PACIFIC ENTOMOLOGIST Vol. 69(1)

Appendix 1. Continued.

Bee species

Host-shrub genera 3

No. bees b

Arct

Cean

Dend

Erio

Mimu

Pick

Rham

Aden

Hete

APIDAE

Apis mellifera (Linnaeus)

Bombus californicus Smith

—

Bombus caliginosus (Frison)

22C

14C

Bombus edwardsii Cresson

70C

Bombus flavifrons (Ashmead)

—

Bombus vosnesenskii Radoszkowski

12C

COLLETIDAE

Hylaeus calvus (Metz)

22C

Hylaeus episcopalis (Cockerell)

28C

Hylaeus modestus citrinifrons (Cockerell)

Nylaeus nevadensis (Cockerell)

—

Hylaeus nunenmacheri Bridwell

21C

—

Hylaeus (Paraprosopis ) undet.

—

Hylaeus polifolii (Cockerell)

48C

37C

Hylaeus rudbeckiae (Cockerell & Casad)

Hylaeus verticalis (Cockerell)

32C

—

HALICTIDAE

Dialictus sp. 20

12C

Dialictus incompletus (Crawford)

Dialictus nevadensis (Crawford)

21C

Dialictus punctatoventris Crawford

—

Dialictus tegulariformis (Crawford)

—

Dialictus undet.

Evylaeus argemonis (Cockerell)

Evylaeus nigrescens (Crawford)

14C

Evylaeus near synthyridis

Evylaeus undet.

Halictus tripartitus Cockerell

26C

10C

Halictus (Seladonia ) undet.

—

Lasioglossum mellipes (Crawford)

1993 DOBSON: CHAPARRAL BEES

Appendix 1. Continued.

Bee species

Host-shrub genera 1

No. bees b

Arct

Cean

Dend Erio

Mimu

Pick

Rham

Aden

Hete

Lasioglossum sisymbrii (Cockerell)

—

Sphecodes sp. 1

—

Sphecodes sp. 2

—

MEGACHILIDAE

Callanthidium illustre (Cresson)

—

Chelostomopsis rubifloris (Cockerell)

15C

Dianthidium plenum Timberlake

—

Heriades occidentalis Michener

—

Hoplitis producta gracilis (Michener)

—

Hoplitis sambuci Titus

13C

—

Megachile b. brevis Say

—

Megachile gemula (Cresson)

—

Megachile gentilis Cresson

—

Megachile ( Leptorachis ) undet.

—

Osmia a. albolateralis Cockerell

—

Osmia b. brevis Cresson

—

Osmia bruneri Cockerell

—

Osmia cobaltina Cresson

—

Osmia cyanella Cockerell

12B

—

Osmia exigua Cresson

—

Osmia gabrielis Cockerell

—

Osmia juxta Cockerell

—

Osmia lignaria propinqua Cresson

—

Osmia ribifloris biedermannii Michener

—

Osmia tristella Cockerell

—

Osmia (Chenosmia ) undet.

—

Trachusa gummifera Thorp

—

a Shrub genera; Arct = Arctostaphylos, Cean = Ceanothus, Erio = Eriodictyon, Dend = Dendromecon, Mimu = Mimulus, Pick = Pickeringia, Aden = Adenostoma,

Hete = Heteromeles. See text for species names.

b Year of collection: A = 1977 only, B = 1978 only, C = both 1977 and 1978.

c Specimen number not specified, since bees not collected in representation of abundance.

THE PAN-PACIFIC ENTOMOLOGIST Yol. 69(1)

PAN-PACIFIC ENTOMOLOGIST

69(1): 95-106, (1993)

FLOWER-VISITING INSECTS OF THE

GALAPAGOS ISLANDS

Conley K. McMullen

Department of Biology and Chemistry, West Liberty State College,

West Liberty, West Virginia 26074

Abstract.— A list of known flower-visiting insects found in the Galapagos Islands is presented.

This information, compiled from the literature and direct observations, represents the first step

toward understanding how angiosperms interact with insects in the Galapagos archipelago.

Key Words.— Insecta, angiosperms, pollination, flower visitation, Galapagos Islands, Ecuador

The taxonomic composition of the Galapagos Islands flora and insect fauna

has been the subject of numerous investigations (Linsley & Usinger 1966, Wiggins

& Porter 1971, Rindge 1973, Hayes 1975, Linsley 1977, Froeschner 1985, Lawes-

son et al. 1987, Peck & Kukalova-Peck 1990, Peck 1991). However, relatively

little is known about the relationships that exist between the insects that inhabit

these islands and the reproductive processes of their flowering neighbors.

One of the first steps taken when attempting to describe an angiosperm’s breed¬

ing strategy is to determine what insects regularly visit its blossoms. Direct field

observations of the plant in question are normally preceded by a review of previous

work on the subject. Unfortunately, the difficulty in obtaining and interpreting

such literature often dissuades workers from continuing. In an effort to expedite

future studies, I have assembled all available records of insect flower-visitation

in the Galapagos Islands, and added to these my most recent field observations

from 14 Jun-11 Aug 1990.

Scientific literature from the first part of this century reveals little of substance

on the topic of insect pollination in this archipelago. Most of what can be found

are casual observations of flower visitors that were made during the many col¬

lecting expeditions to the Galapagos Islands that characterized these early years

(Williams 1911; Beebe 1923, 1924; Wheeler 1924). For example, Williams (1911)

mentioned that Agrius cingulatus Fabr. (Lepidoptera, Sphingidae) (recorded as

Phlegathontius cingulata Fabr.) was commonly seen at flowers during the day,

and Enyo lugubris delanoi Kembach (Lepidoptera, Sphingidae) (recorded as Trip-

togon lugubris L.) was observed visiting a “convolvalaceous” flower on Santa

Cruz Island. Beebe (1923) reported seeing Agraulis vanillae galapagensis Holland

(Lepidoptera, Nymphalidae) “flying slowly from flower to flower” on Santiago

Island, and Hyles lineata florilega Kembach (Lepidoptera, Sphingidae) (recorded

as Deilephila lineata Fabr.) was observed “hovering before small blossoms” during

the day on Baltra Island.

It was not until 1966 that detailed reports were presented on the possible roles

insects played in the ecology and evolution of the Galapagos flora (Linsley 1966,

Linsley et al. 1966). These essays summarized what was then known about the

distribution of potential insect pollinators in the islands, and the plants they were

known to visit. Linsley emphasized the relative dearth of insects in the archipelago,

compared to mainland areas, by pointing out that only one species of bee inhabited

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

the islands. This was an endemic carpenter bee, Xylocopa darwini Cockerell (Hy-

menoptera, Apidae), which was known to visit 60 angiosperm species (Linsley et

al. 1966).

Rick (1963, 1966), Eliasson (1974), Grant & Grant (1981), Aide (1986), and

Elisens (1989) have also contributed to the growing knowledge of pollination

ecology in the Galapagos Islands. In addition, McMullen (1985,1986, 1987, 1989,

1990) has discussed the interactions between plants and insects in this archipelago.

Methods and Materials

Fieldwork was conducted on Pinta Island from 23 Jun-26 Jul 1990. During

this period, breeding studies were performed on six angiosperm species. These

included Justicia galapagana Lindau (Acanthaceae), Darwiniothamnus tenuifolius

(Hooker f.) Harling (Asteraceae), Scalesia baurii Robinson & Greenman ssp.

hopkinsii (Robinson) Eliasson (Asteraceae), Tournefortia rufo-sericea Hooker f.

(Boraginaceae), Plumbago scandens L. (Plumbaginaceae), and Lycopersicon chees-

manii Riley var. minor (Hooker f.) Porter (Solanaceae). Study sites were estab¬

lished at a variety of locations on the southern slope of Pinta ranging from ap¬

proximately 15mto 580min altitude.

Observations were undertaken to determine what insects, if any, were common

visitors to the flowers of these species and might act as pollinators. In addition,

flower visitors of plants not involved in the breeding studies were also noted and

recorded.

Similar studies took place on Santa Cruz from 27 Jul-10 Aug 1990. However,

Scalesia baurii was not included since it does not inhabit this island, and Lyco¬

persicon cheesmanii Riley var. cheesmanii was substituted for var. minor. Study

sites on the southern slope ranged from approximately 90mto 632min altitude

but centered around the area known as Los Gemelos (632 m).

Voucher specimens of each plant species studied were collected in the conven¬

tional manner and deposited in the herbarium of the Charles Darwin Research

Station on Santa Cruz Island, the Galapagos Islands. Specimens of flower visitors

were also obtained and placed in the Station’s research collection. Some duplicate

insect specimens are housed at the Systematic Entomology Laboratory, United

States Department of Agriculture in Beltsville, Maryland; and at Carleton Uni¬

versity, Ottawa, Ontario.

Results and Discussion

Table 1 lists insect flower-visitation records for the Galapagos Islands found

in the literature, as well as those obtained by direct observations during the

summer of 1990. Angiosperms are listed alphabetically by family, genus, and

species. Following each name, in parentheses, is a letter representing the plant’s

resident status.

Insect visitors to the flowers of each plant are listed alphabetically by genus

and species, or by common name if the genus is not known. Authorities, orders,

and families are listed the first time an insect name appears in the table, but not

afterwards. Following the insect’s name, in parentheses, is the island on which

the visit was recorded, and the article in which the visit was published. For

example, Justicia galapagana Lindau is reported as having been visited by Xy¬

locopa darwini Cockerell on Santa Cruz Island in references 8, 9, 12, and 14. If

1993

MCMULLEN: GALAPAGOS FLOWER VISITORS

Table 1. Flower-visiting insects of the Galapagos Islands. Plant status, island, and references follow

the taxa as abbreviations within square brackets. Plant resident status: E, endemic; N, native; C,

cultivated escape; I, introduced. Island names: B, Baltra; D, Daphne Major; E, Espanola; F, Floreana;

G, Genovesa; I, Isabela; P, Pinta; R, Rabida; SCRI, San Cristobal; SC, Santa Cruz; SF, Santa Fe;

STG, Santiago. References: 1, Aide (1986); 2, Beebe (1923); 3, Beebe (1924); 4, Eliasson (1974); 5,

Elisens (1989); 6, Grant & Grant (1981); 7, Hayes (1975); 8, Linsley et al. (1966); 9, McMullen (1985);

10, McMullen (1986); 11, McMullen (1989); 12, McMullen (1990); 13, Rick (1963); 14, Rick (1966);

15, Wheeler (1924); 16, Williams (1911). Numbers for alternative names also refer to references.

Italicized years indicate my summer observations.

ACANTHACEAE

Justicia galapagana Lindau [E] a

Damsel bug nymph (Hemiptera, Nabidae) [P— 1990] b

Leptotes parrhasioides Wallengren (Lepidoptera, Lycaenidae) [SC—10, 12]

Phoebis sennae L. (Lepidoptera, Pieridae) [SC— 1990]

Short-homed grasshopper nymph (Orthoptera, Acrididae) [SC— 1990] b

Toxomerus crockeri Curran (Diptera, Syrphidae) [SC— 1990]

Urbanus dorantes galapagensis Williams (Lepidoptera, Hesperiidae) [SC— 1990] b

Wasmannia auropunctata Roger (Hymenoptera, Formicidae) [SC—10, 12]

Xylocopa darwini Cockerell (Hymenoptera: Apidae) [SC—8, 9, 12, 14]

Tetramerium nervosum Nees (recorded as T. hispidium in 8) [N]

Xylocopa darwini [SC—8]

AIZOACEAE

Sesuvium portulacastrum L. (N) c d

Xylocopa darwini [SC— 1990]

APOCYNACEAE

Catharanthus roseus (L.) George Don [C] c

Phoebis sennae [SC— 1990]

Vallesia glabra (Cavara) Link

Xylocopa darwini [SC—8]

ASTERACEAE

Ageratum conyzoides L. (recorded as A. conyzoides subsp. conyzoides in 12) [N]

Toxomerus crockeri [SC —10, 12]

Bidens pilosa L. [N] a

Phoebis sennae [SC— 1990]

Xylocopa darwini [F— 8]

Darwiniothamnus tenuifolius Hooker f. Harling [E] c d

Atteva hysginiella Wallengren (Lepidoptera, Yponomeutidae) [P—7990] 6

Darwinysius marginalis Dallas (Hemiptera, Lygaeidae) [SC—7990] b

Goniozus sp. (Hymenoptera, Bethylidae) [P—7990] b

Lepidanthrax tinctus Thomas (Diptera, Bombyliidae) [P—7990] b

Moth (Lepidoptera, Gelechioidea, probably Scythrididae) [SC—7990] b

Moth (Lepidoptera, Tortricidae, Olethreutinae) [SC—7990] b

Olcella sp. (Diptera, Chloropidae) [P—7990] b

Orthoperus sp. (Coleoptera, Corylophidae) [P—7990] b

Toxomerus crockeri [SC—7990]

Urbanus dorantes galapagensis [SC—7990] b

Xylocopa darwini [SC—7990]

Encelia hispida Andersson [E]

Heliothis cystiphora Wallengren (Lepidoptera, Noctuidae) [SF—7]

Jaegeria gracilis Hooker f. [E]

Toxomerus crockeri [SC—10, 12]

Macraea laricifolia Hooker f. [E]

Xylocopa darwini [F— 8]

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Continued.

Scalesia affinis Hooker f. [E]

Xylocopa darwini [F—8; SC—4, 8, 14]

Scalesia baurii Robinson & Greenman ssp. hopkinsii (Robinson) Eliasson [E] c

Atteva hysginiella [P— 7990] 6

Lepidanthrax tinctus [P —1990] b

Mythenteles sp. (Diptera, Bombyliidae) [P— 1990] b

Pyralid moth (Lepidoptera, Pyralidae) [P—7990] 6

Rhinacloa sp. (Hemiptera, Miridae) [P—7990] b

Scalesia helleri Robinson [E]

Xylocopa darwini [SC—8, 14; SF—8]

Scalesia pedunculata Hooker f. (recorded as S. pedunculata var. parviflora in 9) [E]

Xylocopa darwini [F—8; SC—8, 9, 12]

Scalesia sp. (probably retroflexa Hemsley) [E]

Xylocopa darwini [SC—8]

Sonchus oleraceus L. [I]

Xylocopa darwini [SC— 11]

AVICENNIACEAE

Avicennia germinans (L.) L. [N]

Paratrechina longicornis Latreille (Hymenoptera, Formicidae) [SC—10, 12]

Tapinoma melanocephalum Fabr. (Hymenoptera, Formicidae) [SC—10, 12]

BORAGINACEAE

Cordia leucophlyctis Hooker f. [E] a

Atteva hysginiella [SC— 7990] f

Disclisioprocta stellata Guenee (Lepidoptera, Geometridae) [SC—10, 12]

Xylocopa darwini [SC—9, 12]

Cordia lutea Lamarck [N] a

Amblycerus piurae Pierce (Coleoptera, Bruchidae) [SC—7 990] b

Atteva hysginiella [B—3] [2]

Beetles [15]

Camponotus planus Wheeler (Hymenoptera, Formicidae) [15]

Chrysopa spp. (Neuroptera, Chrysopidae) [B—3] [15]

Enyo lugubris delanoi Kembach (Lepidoptera, Sphingidae) (recorded as Triptogon lugubris L. in

16) [1-16]

Euchrombius ocellus Haworth (Lepidopetra: Pyralidae) (recorded as Eromene ocellea Haworth in

2 ) [ 2 ]

Green winged hemerobiid (probably Megalomus darwini Banks) (Neuroptera, Hemerobiidae) [2]

Hypasclera collenettei Blair (Coleoptera, Oedemeridae) [SC—7990] b

Hypasclera sp. (recorded as Asclera sp. in 3) [B—3]

Manduca rustica calapagensis Holland (Lepidoptera, Sphingidae) (recorded as Phlegathontius

rustica calapagensis Holland in 16) [1—16]

Melipotis indomita Walker (Lepidoptera, Noctuidae) [SC—7999]'

Metacanthus galapagensis Barber (Hemiptera, Berytidae) [SC—10, 12]

Monomorium floricola Jerdon (Hymenoptera, Formicidae) [G— 15]

Oxacis sp. (Coleoptera, Oedemeridae) [2]

Paratrechina longicornis [SC— 7990]

Paratrechina vaga (Hymenoptera, Formicidae) [SC—10, 12]

Perepitragus fascipes Latr. (Coleoptera, Tenebrionidae) [SC— 7990] b

Phoebis sennae (recorded as Callidryas eubele L. in 2, 3, 16) [B—3; 1—16; SC—7990; SCRI—2) [2]

Urbanus dorantes galapagensis [SC— 7 990] b

Utetheisa galapagensis Wallengren (Lepidoptera, Arctiidae) [SC— 7 990] b

Wasmannia auropunctata [SC—10, 12]

Xylocopa darwini [SC—1, 8, 9, 11, 12, 14, 7990] [15]

1993

MCMULLEN: GALAPAGOS FLOWER VISITORS

Table 1. Continued.

Cordia spp.

Pseudoplusia includens Walker (Lepidoptera, Noctuidae) [7]

Tournefortia psilostachya Humboldt, Bonpland, Kunth [N]

Leptotes parrhasioides [SC—10, 12]

Pyralid moth (Lepidoptera, Pyralidae) [SC—10, 12]

Tournefortia rufo-sericea Hooker f. [E] c

Disclisioprocta stellata [SC— 1990]

Frankliniella sp. (Thysanoptera, Thripidae) [P—1990‘, SC —1990] b

Leafhopper (Homoptera, Cicadellidae) [P—7990; SC—7990] b

Mordellistena galapagoensis Van Dyke (Coleoptera, Mordellidae) [SC—7 990] b

Phoebis sennae [SC—7990]

Utetheisa galapagensis [SC—7990] b

Wasmannia auropunctata [SC—7990]

BRASSICACEAE

Brassica campestris L. [C]

Xylocopa darwini [F—8]

BURSERACEAE

Bur sera graveolens Triana & Planchon [N]

Xylocopa darwini [F—8; SC—8]

CACTACEAE

Opuntia echios Howell var. echios [E]

Ammophorus sp. (Coleoptera, Tenebrionidae) [D—6]

Xylocopa darwini [D—6]

Opuntia echios Howell (probably var. gigantea (Howell) Porter) [E]

Xylocopa darwini [S—8, 14]

Opuntia helleri K. Schumann [E]

Caterpillar [G—6]

Cricket [G—6]

Diptera [G—6]

Manduca rustica calapagensis (recorded as Protoparce rustica galapagoensis Holland in 6)

[G—6]

Monomorium floricola [G—15]

Tetramorium guineense (Fabr.) Wheeler (Hymenoptera, Formicidae) [G—6]

Opuntia megasperma Howell [E]

Xylocopa darwini [SCRI —8]

Opuntia sp. (probably insularis Stewart) [E]

Phoebis sennae (recorded as Callidryas eubele in 16) [1—16]

Opuntia sp. [E]

Agrius cingulatus Fabr. (Lepidoptera, Sphingidae) [7]

CAESALPINIACEAE

Caesalpinia pulcherrima (L.) Swartz [C] c d

Xylocopa darwini [SC—7990]

Cassia occidentalis L. [N]

Xylocopa darwini [SC—8, 9, 12]

Cassia picta George Don [N] a

Phoebis sennae [SC—7990]

Xylocopa darwini [SC— 11]

Cassia sp.

Atteva hysginiella [2]

Euchrombius ocellus (recorded as Eromene ocellea in 2) [2]

Green winged hemerobiid (probably Megalomus darwini) [2]

100

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Continued.

Oxacis sp. [2]

Phoebis sennae (recorded as Callidryas eubele in 2) [2]

Parkinsonia aculeata L. [N]

Xylocopa darwini [E— 8; F—8; SC—8, 9, 11, 12, 1990]

CANNACEAE

Canna sp. [Not Endemic]

Xylocopa darwini [SC—8]

CARICACEAE

Carica papaya L. [C]

Agrius cingulatus [SC—10]

CONVOLYULACEAE

Ipomoea linearifolia Hooker f. [E]

Xylocopa darwini [SC— 11]

Ipomoea pes-caprae (L.) R. Brown [N]

Xylocopa darwini [SC—8]

Ipomoea sp.

Agrius cingulatus [7]

CUCURBITACEAE

Cucurbita pepo [C]

Xylocopa darwini [SC—8]

Mormordica charantia L. (recorded as M. indica in 8) [C]

Leptotes parrhasioides [SC—10]

Wasmannia auropunctata [SC—10]

Xylocopa darwini [SC—8, 13]

EUPHORBIACEAE

Croton scouleri Hooker f. var. scouleri [E] a

Atteva hysginiella [P—7 990] c (male flowers)

Caterpillar [G—6]

Moth [SC-14]

Euphorbia cyathophora J. A. Murray [C] cd

Xylocopa darwini [SC— 1990]

FABACEAE

Crotalaria incana L. (recorded as Crotolaria setifera in 8) [N]

Xylocopa darwini [SC—8]

Galactea striata (Jacquin) Urban (recorded as G. jussiana var. volubilis in 8) [N]

Xylocopa darwini [SC—8]

Geoffroea spinosa Jacquin (recorded as G. striata in 8) [N]

Xylocopa darwini [F— 8]

Piscidia carthagenesis Jacquin (recorded as P. erythrina in 13) [N]

Xylocopa darwini [SC—13]

Rhynchosia minima (L.) de Candolle [N]

Xylocopa darwini [SC—8]

Vigna luteola (Jacquin) Bentham [N] a

Leptotes parrhasioides [SC—10, 12]

Utetheisa ornatrix L. (Lepidoptera, Arctiidae) [SC—1990] b

Xylocopa darwini [SC—9, 12, 1990]

GOODENIACEAE

Scaveola plumieri (L.) M. Vahl [N]

Xylocopa darwini [F—8]

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Table 1. Continued.

Inga edulis Martius [C]

Xylocopa darwini [F—8; SC—8]

Prosopis juliflora (Swartz) de Candolle (recorded as P. dulcis in 8) [N]

Tapinoma melanocephalum [SC—10, 12]

Xylocopa darwini [F— 8; SC—8, 9, 12]

MYRTACEAE

Psidium guajava L. (recorded as P. guayava in 8) [C]

Xylocopa darwini [F— 8; SCRI—8]

NOLANACEAE

Nolana galapagensis Johnston (recorded as Periloba galapagensis in 8, 14) [E]

Xylocopa darwini [SC—8, 14]

NYCTAGINACEAE

Bougainvillea spectabilis Willdenow [C] c

Phoebis sennae [SC— 1990]

Commicarpus tuberosus (Lamarck) Standley (recorded as Boerhaavia scandens in 8) [N]

Leptotes parrhasioides [SC—10, 12]

Xylocopa darwini [SC—8, 11]

Cryptocarpus pyriformis Humboldt, Bonpland, Kunth [N] a

Camponotus sp. (Hymenoptera, Formicidae) [SC— 1990]

Xylocopa darwini [SC—13]

Mirabilis jalapa L. [C]

Xylocopa darwini [SC—8]

PASSIFLORACEAE

Passiflora foetida L. var. galapagensis Killip (recorded as P. foetida in 1,8) [E]

Xylocopa darwini [SC—1, 8, 9, 11, 12, 1990 ]

PLUMBAGINACEAE

Plumbago scandens L. [N] a d

Cardiocondyla nuda Mayr (Hymenoptera, Formicidae) [P— 1990] b

Naucles sp. (Coleoptera, Scraptiidae) [P— 1990] b

Lepidanthrax tinctus [P— 1990] b

Leptotes parrhasioides [P—1990; SC—10, 12, 1990] e

Ornebius erraticus Schudder (Orthoptera, Gryllidae) [P— 1990] b

Paratrechina sp. [P—1990Y

Phoebis sennae [SC—10, 12, 1990]

Urbanus dorantes galapagensis [SC— 1990] b

Wasmannia auropunctata [SC— 1990]

Xylocopa darwini [SC— 1990]

POACEAE

Setaria geniculta (Lamarck) Beauvois [N]

Wasmannia auropunctata [SC—10, 12]

POLYGONACEAE

Polygonum opelousanum Small [N]

Toxomerus crocked [SC—10, 12]

PORTULACACEAE

Portulaca oleracea L. [N]

Xylocopa darwini [SC—8]

RUBIACEAE

Borreria sp.

Diptera [SC—14]

1993

MCMULLEN: GALAPAGOS FLOWER VISITORS

101

Table 1. Continued.

LAURACEAE

Persea americana Miller (recorded as P. gratissima in 8) [C]

Xylocopa darwini [SC—8]

LOASACEAE

Mentzelia aspera L. [N]

Xylocopa darwini [SC— 1, 8]

LYTHRACEAE

Cuphea racemosa (L. f.) Sprengel [I] ad

Leptotes parrhasioides [SC—10, 12]

Toxomerus crockeri [SC—10, 12]

Xylocopa darwini [SC— 1990]

MALVACEAE

Abelmoschus manihot (L.) Medicus (recorded as Hibiscus manihot in 8) [I]

Xylocopa darwini [SC—8]

Abutilon depauperatum (Hooker f.) Robinson [E]

Xylocopa darwini [SC—1, 8]

Bastardia viscosa (L.) Humboldt, Bonpland, Kunth [N]

Xylocopa darwini [SC—8, 9, 11, 12]

Gossypium barbadense L. var. darwinii (Watt) J. B. Hutchinson [E]

Phoebis sennae (recorded as Callidryas eubele in 2) [SC—10, 12; SCRI—2]

Xylocopa darwini [1—8]

Gossypium sp. [E]

Atteva hysginiella [2]

Euchrombius ocellus (recorded as Eromene ocellea in 2) [2]

Green winged hemerobiid (probably Megalomus darwini) [2]

Oxacis sp. [2]

Phoebis sennae (recorded as Callidryas eubele in 2, 16) [1—16] [2]

Hibiscus tiliaceus L. [N]

Xylocopa darwini [SC— 8 , 11, 1990 ]

Malvastrum coromandelianum (L.) Garcke [I]

Xylocopa darwini [SC—8]

Sida acuta Burman f. [I]

Xylocopa darwini [SC—8]

Sida paniculata L. [I]

Xylocopa darwini [F—8]

Sida rhombifolia L. [I] a

Leptotes parrhasioides [SC—10, 12]

Phoebis sennae [SC— / 990]

Utetheisa ornatrix [SC— 1990] h

Xylocopa darwini [F—8; SC—8, 9, 12, 1990 ]

Sida spinosa L. (recorded as S. angustifolia in 8) [N]

Xylocopa darwini [F—8; SC—8]

MELASTOMATACEAE

Miconia robinsoniana Cogniau [E]

Xylocopa darwini [SC—8]

MIMOSACEAE

Acacia insulae-iacobi Riley (recorded as A. tortuosa in 8) [N] a

Urbanus dorantes galapagensis [SC— 1990] b

Xylocopa darwini [SC—8, 11]

Acacia macracantha Willdenow [N]

Xylocopa darwini [F—8; SC—8]

1993

MCMULLEN: GALAPAGOS FLOWER VISITORS

103

Table 1. Continued.

Chiococca alba (L.) A. S. Hitchcock [N]

Xylocopa darwini [SC—8]

Coffea arabica L. [C]

Xylocopa darwini [SC—8, 9]

Diodia radula Chamisso & Schlechter [I] a

Phoebis sennae [SC— 1990]

Toxomerus crockeri [ SC—10, 12, 1990]

Urbanus dorantes galapagensis [SC— 1990] h

Psychotria rufipes Hooker f. [E]

Xylocopa darwini [SC—8]

SAPINDACEAE

Cardiospermum galapageium Robinson & Greenman (recorded as C. galapageum in 8) [E]

Xylocopa darwini [SC—8, 18]

SCROPHULARIACEAE

Bacopa monniera [Not Endemic]

Xylocopa darwini [SC—8]

Galvezia leucantha Wiggins var. leucantha [E]

Xylocopa darwini [1—5]

Galvezia leucantha Wiggins var. pubescens Wiggins [E]

Xylocopa darwini [R—5]

SIMAROUBACEAE

Castela galapageia Hooker f. [E]

Xylocopa darwini [SC—8, 14, 1990]

SOLANACEAE

Cacabus miersii (Wellstein f.) D’Arcy [E]

Agrius cingulatus [7]

Capsicum frutescens L. [C]

Wasmannia auropunctata [SC—10, 12]

Lycopersicon cheesmanii Riley var. cheesmanii (recorded as L. pimpinellifolium in 13, 14) [E] a

Leptotes parrhasioides [SC— 1990]

Urbanus dorantes galapagensis [SC— 1990] b

Xylocopa darwini [ SC—11, 13, 14, 1990]

Lycopersicon cheesmanii Riley var. minor (Hooker f.) Porter [E] c

Leaf bug (Hemiptera, Miridae) [P— 1990] b

Physalis pubescens L. [N]

Xylocopa darwini [SC—8]

Solanum americanum Miller [N] a

Toxomerus crockeri [SC— 1990]

Xylocopa darwini [SC— 11]

STERCULIACEAE

Waltheria ovata Cavanilles (recorded as W. reticulata in 8) [N] a

Atteva hysginiella [P— 1990] c

Xylocopa darwini [SC—8, 11, 1990]

VERBENACEAE

Clerodendrum molle Humboldt, Bonpland, Kunth var. glabrescens Svenson [E]

Xylocopa darwini [SC— 11]

Clerodendrum molle Humboldt, Bonpland, Kunth var. mode [N]

Ant (Hymenoptera, Formicidae) [SC—10, 12]

Hawk moth (Lepidoptera, Sphingidae) [SC—10, 12]

Xylocopa darwini [SC—9, 11, 12, 1990]

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Table 1. Continued.

Clerodendrum molle Humboldt, Bonpland, Kunth (variety not known)

Manduca rustica calapagensis (recorded as Phlegathontius rustica calapagensis in 16) [1—16]

Pseudoplusia includens [7]

Xylocopa darwini [SC—8]

Lantana peduncularis Andersson [E]

Xylocopa darwini [SC—8, 11]

Phyla sp. [Not Endemic] 0

Leptotes parrhasioides [SC— 1990]

Stachytarpheta cayennensis (Richard) M. Vahl (recorded as S. cayannensis in 8) [I]

Xylocopa darwini [F—8]

ZYGOPHYLLACEAE

Tribulus cistoides L. [N]

Leptotes parrhasioides [SC—10, 12]

Xylocopa darwini [SC—8, 9, 12]

a Flowers reported as visited by new insects.

b Insect reported for the first time as a flower visitor in the Galapagos Islands.

c Flowers reported for the first time as visited by insects in the Galapagos Islands.

d Flowers reported for the first time as visited by Xylocopa darwini.

e Insect reported for the first time as a flower visitor on Pinta Island.

f Insect reported for the first time as a flower visitor on Santa Cruz Island.

the island is not known, the reference number appears alone in square brackets.

The designation “7990” represents an observation by me during the summer of

that year.

The observations from 1990 provide several new records. Ten angiosperms,

representing nine families, are reported for the first time as having their flowers

visited by insects in the Galapagos Islands. In addition, new insect visitors are

reported for 16 angiosperms from 14 families. Six flowering plants are reported

for the first time as having their blossoms visited by Xylocopa darwini.

Twenty-four insects, representing eight orders, are reported for the first time as

flower visitors in the Galapagos; four insects are reported as flower visitors for

the first time on Pinta Island, and two are reported for the first time on Santa

Cruz Island. Although no other references than mine are listed in the table for

Melipotis indomita Walker (Lepidoptera, Noctuidae), it is not listed as a first time

flower visitor in the Galapagos because Hayes (1975) mentions that “adults come

to flowers at dusk in the rainy season.”

Table 1 indicates that Xylocopa darwini is the primary flower visitor on the

islands that it inhabits. The vast majority of these visits have been made by female

bees. In fact, all but two of the carpenter bee records from 1990 refer exclusively

to female visitors. Only Cordia lutea Lamarck (Boraginaceae) and Waltheria ovata

Cavanilles (Sterculiaceae) were observed being visited by both male and female

bees.

A total of 79 plant taxa, from 35 families, are listed that have been visited by

this polytropic bee, with 25 of these being endemics. Apparently, the more recent

arrivals to the Galapagos Islands are favored as sources of pollen and nectar.

Although members of several different families are visited, the legumes, mallows,

and composites are especially well represented.

1993

MCMULLEN: GALAPAGOS FLOWER VISITORS

105

Among the other flower visitors observed in 1990, an Olcella sp. (Diptera:

Chloropidae), a Goniozus sp. (Hymenoptera: Bethylidae), and a Leptotes parrhasi-

oides Wallengren (Lepidoptera: Lycaenidae) appeared to be most common on

Pinta Island. On Santa Cruz, Toxomerus crocked Curran (Diptera: Syrphidae)

and Phoebis sennae L. (Lepidoptera: Pieridae) were extremely active.

In summary, this paper represents the first phase of a study designed to un¬

derstand the reproductive relationships that exist between the plant and insect

coinhabitants of the Galapagos Islands. It should be noted that this listing does

not assign any particular value to each flower visitor. Undoubtedly, some of these

insects are more important pollen vectors than others. Details can be found in

the literature cited, or in the case of the 1990 observations, in future publications.

Acknowledgment

I thank the following individuals for their assistance with various aspects of

this study: Scott Andrews, David D. Close, Gayle Davis-Merlen, Bryan E. Dutton,

Aracelly Fajardo, Richard C. Froeschner, Mary Lacey-Theisen, Sandra Naranjo,

and Hugo Valdebenito. Most of the insect identifications for this study were made

by the following individuals associated with the Systematic Entomology Labo¬

ratory, United States Department of Agriculture, Beltsville, Maryland: C. H.

Dietrich (Homoptera), D. C. Ferguson (Lepidoptera), T. J. Henry (Hemiptera),

R. W. Hodges (Lepidoptera), J. M. Kingsolver (Coleoptera), A. S. Menke (Hy¬

menoptera), S. Nakahara (Thysanoptera), D. A. Nickle (Orthoptera), J. Pakaluk

(Coleoptera), R. W. Poole (Lepidoptera), F. C. Thompson (Diptera), C. W. Sa-

brosky (Diptera), D. R. Smith (Hymenoptera), T. J. Spilman (Coleoptera), N.

Vandenberg (Coleoptera). Additional identifications were made by N. L. Evenhuis

(Diptera) of the Bernice P. Bishop Museum, Honolulu, Hawaii; and S. B. Peck

(Coleoptera) and B. J. Sinclair (Diptera) of Carleton University, Ottawa, Canada.

I also express my appreciation to the staffs of the Charles Darwin Research Station

and Galapagos National Park Service. This work was supported by National

Geographic grant 4327-90.

Literature Cited

Aide, M. 1986. The influence of Xylocopa darwini on floral evolution in the Galapagos. Charles

Darwin Research Station (Galapagos Islands), Annual Report, 1983: 19-21.

Beebe, W. 1923. Notes on Galapagos Lepidoptera. Zoologica, 5: 51-59.

Beebe, W. 1924. Galapagos: world’s end. G. P. Putnam’s Sons, New York.

Eliasson, U. 1974. Studies in Galapagos plants. XIV. The genus Scalesia Arn. Opera Botanica, 36:

1-117.

Elisens, W. J. 1989. Genetic variation and evolution of the Galapagos shrub snapdragon. Nat. Geo.

Res., 5: 98-110.

Froeschner, R. C. 1985. Synopsis of the Heteroptera or true bugs of the Galapagos Islands. Smithson.

Contr. Zool., 407: 1-84.

Grant, B. R. & P. R. Grant. 1981. Exploitation of Opuntia cactus by birds on the Galapagos. Oecologia

(Berlin), 49: 179-187.

Hayes, A. H. 1975. The larger moths of the Galapagos Islands (Geometroidea: Sphingoidea &

Noctuoidea). Proc. Calif. Acad. Sci., 40: 145-208.

Lawesson, J. E., H. Adsersen & P. Bentley. 1987. An annotated checklist of the vascular plants of

the Galapagos Islands. Reports Botanical Institute, Univ. of Aarhus, Denmark, 16: 1-74.

Linsley, E. G. 1966. Pollinating insects of the Galapagos Islands, pp. 225-232. In Bowman, R. I.

(ed.). The Galapagos. Univ. California Press, Berkeley.

Linsley, E. G. 1977. Insects of the Galapagos (supplement). Occas. Pap. Calif. Acad. Sci., 125: 1-50.

106

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Linsley, E. G. & R. L. Usinger. 1966. Insects of the Galapagos Islands. Proc. Calif. Acad. Sci., 33:

113-196.

Linsley, E. G., C. M. Rick & S. G. Stephens. 1966. Observations on the floral relationships of the

Galapagos carpenter bee. Pan-Pacif. Entomol., 42: 1-18.

McMullen, C. K. 1985. Observations on insect visitors to flowering plants of Isla Santa Cruz. I. The

endemic carpenter bee. Not. de Galapagos, 42: 24-25.

McMullen, C. K. 1986. Observations on insect visitors to flowering plants of Isla Santa Cruz. II.

Butterflies, moths, ants, hover flies, and stilt bugs. Not. de Galapagos, 43: 21-23.

McMullen, C. K. 1987. Breeding systems of selected Galapagos Islands angiosperms. Amer. J. Bot.,

74: 1694-1705.

McMullen, C. K. 1989. The Galapagos carpenter bee, just how important is it? Not. de Galapagos,

48: 16-18.

McMullen, C. K. 1990. Reproductive biology of Galapagos Islands angiosperms. Monogr. Syst. Bot.

(Missouri Bot. Gard.), 32: 35-45.

Peck, S. B. 1991. The Galapagos Archipelago, Ecuador: with an emphasis on terrestrial invertebrates,

especially insects: and an outline for research, pp. 319-336. In Dudley, E. C. (ed.). The unity

of evolutionary biology. Proceedings of the fourth international congress of systematic and

evolutionary biology, University of Maryland, College Park, Maryland, July 1990. Dioscorides

Press, Portland, Oregon.

Peck, S. B. & J. Kukalova-Peck. 1990. Origin and biogeography of the beetles (Coleoptera) of the

Galapagos Archipelago, Ecuador. Can. J. Zook, 68: 1617-1638.

Rick, C. M. 1963. Biosystematic studies on Galapagos tomatoes. Occas. Pap. Calif. Acad. Sci., 44:

59-77.

Rick, C. M. 1966. Some plant-animal relations on the Galapagos Islands, pp. 215-224. In Bowman,

R. I. (ed.). The Galapagos. Univ. California Press, Berkeley.

Rindge, F. H. 1973. The Geometridae (Lepidoptera) of the Galapagos Islands. Amer. Mus. Novit.,

2510: 1-31.

Wheeler, W. M. 1924. The Formicidae of the Harrison Williams Galapagos expedition. Zoologica,

5: 101-122.

Wiggins, I. L. & D. M. Porter. 1971. Flora of the Galapagos Islands. Stanford Univ. Press, Stanford,

California.

Williams, F. X. 1911. Expedition of the California Academy of Sciences to the Galapagos Islands,

1905-1906. III. The butterflies and hawk-moths of the Galapagos Islands. Proc. Calif. Acad.

Sci., 1: 289-322.

Received 8 June 1992; accepted 26 October 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 107-109, (1993)

Scientific Note

NEW HOST RECORD FOR

ACANTHOSCELIDES CLANDESTINES (MOTSCHULSKY)

(COLEOPTERA: BRUCHIDAE) FROM BRAZIL

Acanthoscelides clandestinus (Motschulsky) was recently reared from the seeds

of Phaseolus uleanus Harms (Fig. 1) from Brazil by G. P. Lewis and S. M. M. de

Andrade in the state of Bahia, c. 4 km along estrada de terra, from Livramento

do Brumado to Rio de Contas, c. 41°51' W, 13°38' S, on 28 Mar 1991. This is

the first record of a bruchid feeding in the seeds of this plant. The only valid host

for this bruchid had been Phaseolus vulgaris L. (Johnson, C. D. 1983. Misc. Publ.

Entomol. Soc. Am., 56). It has also been reported to feed in Cajanus cajan (L.)

Millspaugh (Johnson, C. D. 1990. Trans. Am. Entomol. Soc., 116: 297-618), a

record that must be verified.

Phaseolus uleanus (Fig. 2) was described in 1909, but as recently as 1977 it was

still only known by the type-specimen, E. Ule 7215. Marechal et al. (Marechal,

R., J.-M. Mascherpa & F. Stainier. 1978. Boissiera, 28: 150-151) found the plant

difficult to place taxonomically due to a lack of information about seedlings, fruits

(Fig. 3) and seeds. They suggested a close relationship with Ramirezella and Vigna

subgenus Sigmoidotropis. Since 1977, several new collections of P. uleanus have

been made in Bahia, Brazil and recently seeds have been germinated and chro-

Figure 1. Mature seeds and pods (fruits) of Phaseolus uleanus.

108

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(1)

Figure 2. Growth habit of Phaseolus uleanus.

mosomes counted. The current view is that the plant requires a new generic name

and GPL is preparing a paper to formalize this.

Two species closely related to A. clandestinus have updated host names. Acan-

thoscelides caracallae Kingsolver feeds in Vigna caracalla (L.) Verdcourt (= Pha¬

seolus caracalla L.) and A comptus Kingsolver in Vigna aff. peduncularis (Kunth)

Fawcett & Rendle (= P. aff. peduncularis Kunth). Acanthoscelides caracallae has

been recorded from Argentina and Paraguay, but A. comptus has only been found

in Argentina. Acanthoscelides clandestinus has a much wider distribution that

includes Mexico, Guatemala, Honduras, Panama, Colombia, Venezuela, Suri¬

nam, Brazil and Peru (Johnson 1990). All are of potential economic importance

because all feed in species of beans in the genera Phaseolus and Vigna.

Acknowledgment. — We thank Margaret Johnson for assistance in the field and

the laboratory.

1993

SCIENTIFIC NOTE

109

Figure 3. Mature and immature flowers and immature pods (fruits) of Phaseolus uleanus.

Clarence Dan Johnson 1 and Gwilym P. Lewis, 21 Department of Biological Sci¬

ences, Northern Arizona University, Flagstaff, Arizona 86011-9989; 2 Herbarium,

Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, Great Britain.

Received 23 January 1992; accepted 8 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 109-110, (1993)

Scientific Note

NEST CONSTRUCTION PLASTICITY IN

OSMIA RIBIFLORIS BIEDERMANNII MICHENER

(HYMENOPTERA: MEGACHILIDAE)

Cavity-nesting wasps and bees use a variety of materials in the construction of

cell partitions and nest plugs (Malyshev, S. I. 1935. Eos, 11: 210-309; Linsley,

E. G. 1958. Hilgardia, 27: 543-599; Krombein, K. Y. 1967. Trap-Nesting Wasps

and Bees. Smithsonian Press, Washington, D.C.). The choice of materials is or¬

dinarily species specific and usually constant (numerous individual species ac¬

counts). Here, I report on the use of a new material in the construction of cell

partitions and nest plugs in the bee Osmia ribifloris beidermannii Michener. This

use was not from an isolated nest, but from several nests and from two different

nesting seasons.

110

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

Figure 1. Cell partitions from Osmia ribifloris biedermannii nests. Top row are masticated leaf

material partitions (most likely Taraxacum officinale leaves) from a 7 mm nest and the bottom row

shows the inner most partition of masticated leaf (left), the next partition with threshold of masticated

leaf but filled with pine resin, and two complete resin partitions from outer cells of the nest.

Osmia r. biedermannii uses masticated leaf material in cell partition and nest

plug construction, most likely dandelion ( Taraxacum officinale Wiggers) in field

populations and Oenothera hookeri T. & G. in a greenhouse population (Rust, R.

W. 1986. J. Kansas Entomol. Soc., 59: 89-94). Trap-nests (pine blocks 1.9 x 1.9

x 15 cm and drilled with 5-9 mm holes) from Reno, Nevada from 1990 (32),

1991 (75) and 1992 (23) contained nests (3 or 9.4% in 1990, 6 or 8.0% in 1991

and 3 or 30% in 1992) in which the bee had used pine resin in both partition and

nest plug construction (Fig. 1). The resin partitions were the same thickness as

those of masticated leaf from similar diameter holes. However, they were statis¬

tically heavier (t = 13.56, df = 12, P > 0.001, masticated leaf mean 17.8 ± 3.5

mg (SD) and resin mean 55.2 ± 6.0 mg) in 7 mm diameter holes. Nest plugs were

also heavier (109.8 to 29.2 mg) in the resin nests of similar diameter. All nests

in which resin was substituted for masticated plant material were from trap-nest

bundles attached to pine trees ( Pinus spp.). Also, the inner most partitions were

of masticated plant material with the resin partitions and plugs completing the

with the resin partitions and plugs completing the nest structure (Fig. 1).

The appearance of resin in partition and plug construction in a nest could be

considered an error or mistake by one individual. However, its appearance in

several nests and in several different nesting seasons suggests that the ability to

substitute construction materials is a behavioral plasticity, at least in the popu¬

lation of O. r. biedermannii from the Reno, Nevada area. Because all nests were

opened in the laboratory, it is not known if the progeny in resin nests can effectively

chew through the resin partitions and plugs during their spring emergence.

Richard W. Rust, Department of Biology, University of Nevada, Reno, Nevada

89557.

Received 18 May 1992; accepted 14 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(1): 111-113, (1993)

Scientific Note

THE FORMOSAN SUBTERRANEAN TERMITE,

COPTOTERMES FORMOSANUS SHIRAKI

(ISOPTERA: RHINOTERMITIDAE),

ESTABLISHED IN CALIFORNIA

The Formosan subterranean termite, Coptotermes formosanus Shiraki, which

has been introduced into subtropical, coastal areas throughout the world (including

Hawaii, Louisiana, Alabama, Mississippi, Florida, Texas, and South Carolina),

is native to mainland China. Although it is primarily known as a structural pest,

it can be an agricultural pest because of its habit of consuming the heartwood of

living trees (Su, N.-Y. & M. Tamashiro. 1987. pp. 3-14. In Tamashiro, M. & N.-

Y. Su (eds.). Biology and control of the formosan subterranean termite. Hawaii

Inst. Agric. Human Resources Research Extension Ser., 83). In the United States,

it has become the major economic pest of structures in areas where it has been

introduced because of its destructiveness and control problems. In mid-February

1992, a pest control operator in the San Diego area submitted a sample of several

termite soldiers from a residential property in La Mesa at which he had experi¬

enced difficulty in achieving satisfactory control. The soldiers were identified as

Coptotermes species by comparison with voucher material. Definitive identifi¬

cation was made by Dr. Rudolf Scheffrahn (University of Florida, Fort Lauderdale,

Florida) on the basis of dried alates collected in the attic of the home at a later

collected in the attic of the home at a later date.

We visited the site on 5 Mar 1992 to look for evidence of termite activity. The

house (built in the late 1940s) is situated on a moist hillside in a former vegetable

farm with abundant fruit trees. The property is heavily irrigated with a combi¬

nation of drip and sprinkler systems. Numerous dead bodies of termite soldiers

and workers were observed inside the house under the carpet along a previously

treated wall. In the attic, we found many cadavers inside the eaves above the wall

where termite activity had been noted. There had been no live termites or corpses

in this area several weeks previously when the same area had been inspected by

the pest control operator. The dead termites observed in the attic probably had

died as a result of the chlorpyrifos treatment, either from direct intoxication or

as a consequence of the termites inside the structure being cut off from the soil.

We noted numerous shed wings of Coptotermes alates in the attic. These shed

wings might have been overlooked during initial inspections or confused with

those of drywood termites, which were known to occur there. Several intact,

desiccated alates were found in spider webs.

Inspection of the property revealed Coptotermes activity in wood that was

buried or in contact with the soil (steps, tree stumps, raised borders of beds,

fences), planters made from oak barrels cut in half, and a raised wooden deck.

Active termite foraging was observed up to the property lines on three sides of

the property (the fourth side faces the street). The large numbers of workers and

112

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(1)

soldiers, their large size, and the amount of damaged wood on the site were

remarkable. We found no live termites inside the house or indications of active

structural infestation on 5 Mar, indicating that contact between the termite colony

and the structure had been broken. Live soldiers and workers were again noted

on 28 Mar, suggesting that the termites had found an untreated access route to

the wall. On that date, neighboring properties were inspected for evidence of

Formosan subterranean termite activity. Live termites were found on a total of

four adjacent properties, but not in others on either side of these.

Although C.formosanus has been intercepted in California on several occasions,

this is the first case in which it has become established. The presence of wings in

the structure indicates that there is at least one mature colony in the area, because

alates are not produced by young colonies. A neighbor indicated that he had

observed termite swarms in the early evening during the past several years. These

were probably C. formosanus because native subterranean and drywood termite

species typically swarm during daylight hours. Laboratory colonies have produced

alates within 10 years, although it is believed that alates would be produced in

less time (5-6 years) under field conditions (Su & Tamashiro 1987). The large

size of the workers (4.27 ± 0.09 mg, average of five groups of 10 workers) and

soldiers is typical of mature colonies, probably greater than 10 years old (Rudolf

Scheffrahn, personal communication). We have no indication of how many col¬

onies might be involved. The total area in which we observed five termites is

within the foraging range of a single colony (the maximum distance between sites

of observed activity across the four properties was approximately 100 m) (Su, N.-

Y. & R. H. Scheffrahn. 1988. Sociobiology, 14: 353-359). Swarming alates may

have established new colonies that were not detected in our preliminary surveys.

Because most introductions of the Formosan subterranean termite have been

in seaports in tropical and subtropical areas of the world, regulatory attention has

focused on port areas. The La Mesa infestation, however, is over 9.4 km (15

miles) inland. The source of the original colony may have been neighbors who

moved into the area with all of their personal belongings in June of 1976 from

an infested part of Hawaii. This scenario could easily be repeated with the ex¬

tensive contacts between California and Hawaii and countries of the Pacific Rim.

The possibility of overland introduction of colonies cannot be ruled out, as this

termite is now well established in many areas of the southeastern United States.

A mated pair of alates could be transported under conditions suitable for their

survival and placed in an appropriate setting on arrival. This could be in potted

plants, nursery material, outdoor furniture, among other possibilities. Although

the climate of most parts of California is much drier than that of many areas

where the Formosan subterranean termite has become established, properties that

are heavily shaded and irrigated, such as the one at La Mesa, provide a suitable

microhabitat for establishment and subsequent colony growth.

Material Examined.— CALIFORNIA. SAN DIEGO Co.: La Mesa, 5 Mar 1992, T. H. Atkinson,

M. K. Rust & J. M. Smith.

Acknowledgment.— Mike Cole, Algon Exterminating, El Cajon, was the local

pest control operator who first detected the problem. Steve Fleming, DowElanco,

San Diego, submitted the first specimens for identification. David Kellum, San

1993

SCIENTIFIC NOTE

113

Diego Co. Agricultural Commisioner’s Office, obtained permission from neigh¬

boring homeowners for the follow-up survey on 28 Mar.

Thomas H. Atkinson, Michael K. Rust and James L. Smith, Department of

Entomology, University of California, Riverside, California 92521.

Received 17 April 1992; accepted 17 September 1992.

Editorial Notice

Pan-Pacific Entomologist

Additions to the Editorial Staff

The editorial staff of the Pan-Pacific Entomologist has increased, with appoint¬

ment of Dr. Robert V. Dowell as Associate Editor, effective with volume 69. The

staff now includes: an Editor (John T. Sorensen), Associate Editor (Robert V.

Dowell), Book Review Editor (Ronald E. Somerby) and Editorial Assistant (Susan

M. Sawyer).

Although Dr. Dowell will handle non-taxonomic manuscripts, please continue

to send all correspondence and submissions directly to the Editor for handling

efficiency. This staff increase was necessitated by the State of California’s 1993—

94 budget restrictions, and resulting additions to the regular workload of its

employees.

PAN-PACIFIC ENTOMOLOGIST

Information for Contributors

See volume 66 (1): 1-8, January 1990, for detailed format information and the issues thereafter for examples. Manuscripts must be

in English, but foreign language summaries are permitted. Manuscripts not meeting the format guidelines may be returned. Please

maintain a copy of the article on a word-processor because revisions are usually necessary before acceptance, pending review and copy¬

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nonerasable, high quality paper. THREE (3) COPIES of each manuscript must be submitted, EACH INCLUDING REDUCTIONS

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pages (pages 3+), acknowledgment page, literature cited pages, footnote page, tables, figure caption page; place original figures last.

List the corresponding author’s name, address including ZIP code, and phone number on the title page in the upper right comer. The

title must include the taxon’s designation, where appropriate, as: (Order: Family). The ABSTRACT must not exceed 250 words; use

five to seven words or concise phrases as KEY WORDS. Number FOOTNOTES sequentially and list on a separate page.

Text. — Demarcate MAJOR HEADINGS as centered headings and MINOR HEADINGS as left indented paragraphs with lead phrases

underlined and followed by a period and two hypens. CITATION FORMATS are: Coswell (1986), (Asher 1987a, Franks & Ebbet

1988, Dorly et al. 1989), (Burton in press) and (R. F. Tray, personal communication). For multiple papers by the same author use:

(Weber 1932, 1936, 1941; Sebb 1950, 1952). For more detailed reference use: (Smith 1983: 149-153, Price 1985: fig. 7a, Nothwith

1987: table 3).

Taxonomy. — Systematics manuscripts have special requirements outlined in volume 66(1): 1-8, including SEPARATE PARAGRAPHS

FOR DIAGNOSES, TYPES AND MATERIAL EXAMINED (INCLUDING A SPECIFIC FORMAT), and a specific order for

paragraphs in descriptions. See: Johnson, K. (1990. Pan-Pacif. Entomol., 66[2]: 97-125) for an example of format style and order

for taxonomic descriptions. Please request a copy of special format requirements from the editor. List the unabbreviated taxonomic

author of each species after its first mention.

Literature Cited. — Format examples are:

Anderson, T. W. 1984. An introduction to multivariate statistical analysis (2nd ed). John Wiley & Sons, New York.

Blackman, R. L., P. A. Brown & V. F. Eastop. 1987. Problems in pest aphid taxonomy: can chromosomes plus morphometries

provide some answers? pp. 233-238. In Holman, J., J. Pelikan, A. G. F. Dixon & L. Weismann (eds.). Population structure, genetics

and taxonomy of aphids and Thysanoptera. Proc. international symposium held at Smolenice Czechoslovakia, Sept. 9-14, 1985.

SPB Academic Publishing, The Hague, The Netherlands.

Ferrari, J. A. & K. S. Rai. 1989. Phenotypic correlates of genome size variation in Aedes albopictus. Evolution, 42: 895-899.

Sorensen, J. T. (in press). Three new species of Essigella (Homoptera: Aphididae). Pan-Pacif. Entomol.

Illustrations. — Illustrations must be of high quality and large enough to ultimately reduce to 117 x 181 mm while maintaining label

letter sizes of at least 1 mm; this reduction must also allow for space below the illustrations for the typeset figure captions. Authors

are strongly encouraged to provide illustrations no larger than 8.5 x 11 in for easy handling. Number figures in the order presented.

Mount all illustrations. Label illustrations on the back noting: (1) figure number, (2) direction of top, (3) author’s name, (4) title of

the manuscript, and (5) journal. FIGURE CAPTIONS must be on a separate, numbered page; do not attach captions to the figures.

Tables. — Keep tables to a minimum and do not reduce them. Table must be DOUBLE-SPACED THROUGHOUT and continued

on additional sheets of paper as necessary. Designate footnotes within tables by alphabetic letter.

Scientific Notes. — Notes use an abbreviated format and lack: an abstract, key words, footnotes, section headings and a Literature Cited

section. Minimal references are listed in the text in the format: (Bohart, R. M. 1989. Pan-Pacific. Entomol., 65: 156-161.). A short

acknowledgment is permitted as a minor headed paragraph. Authors and affiliations are listed in the last, left indented paragraph of

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for a grant to cover up to one half of these charges. Nonmembers are charged $60 per page. Page charges do not include reprint costs,

or charges for author changes to manuscripts after they are sent to the printer.

Volume 69

THE PAN-PACIFIC ENTOMOLOGIST

January 1993

Number 1

Contents

SHEPARD, W. D.—An annotated checklist of the aquatic and semiaquatic dryopoid Coleoptera

of California. 1

LAVIGNE, R. J. —Notes on the ethology of Dicolonus sparsipilosum Back (Diptera:

Asilidae). 12

BARRENTINE, C. D.—Toads ( Bufo boreas Baird & Girard) obtain no calories from ingested

Sphenophorus phoeniciensis Chittenden (Coleoptera: Curculionidae) .. 15

GREEN, J. F., D. H. HEADRICK & R. D. GOEDEN—Life history and description of immature

stages of Procecidochares stonei Blanc & Foote on Viguiera spp. in southern California

(Diptera: Tephritidae)_ 18

SEYBOLD, S. J. & D. L. WOOD—Extended development of Polycaon stoutii (LeConte) (Co¬

leoptera: Bostrichidae). 33

SEYBOLD, S. J. & J. L. TUPY —Ernobius mollis (L.) (Coleoptera: Anobiidae) established in

California. 36

OWEN, W. R.—Host plant preferences of Acanthoscelides aureolus (Horn) (Coleoptera: Bru-

chidae). 41

STRONG, K. L. & J. K. GRACE—Low allozyme variation in Formosan subterranean termite

(Isoptera: Rhinotermitidae) colonies in Hawaii. 51

UNRUH, T. R., B. D. CONGDON & E. LAGASA— Yponomeuta malinellus Zeller (Lepidop-

tera: Yponomeutidae), a new immigrant pest of apples in the northwest: phenology and

distribution expansion, with notes on efficacy of natural enemies . 57

QURESHI, Z., T. HUSSAIN, J. R. CAREY & R. V. DOWELL-Effects of temperature on

development of Bactrocera zonata (Saunders) (Diptera: Tephritidae). 71

DOBSON, H. E. M. —Bee fauna associated with shrubs in two California chaparral communi¬

ties . 77

McMULLEN, C. K.—Flower-visiting insects of the Galapagos Islands. 95

SCIENTIFIC NOTES

JOHNSON, C. D. & G. P. LEWIS—New host record for Acanthoscelides clandestinus (Mot-

schulsky) (Coleoptera: Bruchidae) from Brazil. 107

RUST, R. W.—Nest construction plasticity in Osmia ribifloris biedermannii Michener (Hy-

menoptera: Megachilidae). 109

ATKINSON, T. H., M. K. RUST & J. L. SMITH—The Formosan subterranean termite,

Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), established in California 111

Editorial notice: Additions to the editorial staff. 113

The

PAN-PACIFIC

ENTOMOLOGIST

Volume 69 April 1993 Number 2

Published by the PACIFIC COAST ENTOMOLOGICAL SOCIETY

in cooperation with THE CALIFORNIA ACADEMY OF SCIENCES

(ISSN 0031-0603)

The Pan-Pacific Entomologist

EDITORIAL BOARD

J. T. Sorensen, Editor

R. V. Dowell, Associate Editor

R. E. Somerby, Book Review Editor

S. M. Sawyer, Editorial Assist.

Paul H. Amaud, Jr., Treasurer

R. M. Bohart

J. T. Doyen

J. E. Hafemik, Jr.

J. A. Powell

Published quarterly in January, April, July, and October with Society Proceed¬

ings usually appearing in the October issue. All communications regarding non¬

receipt of numbers, requests for sample copies, and financial communications

should be addressed to: Paul H. Amaud, Jr., Treasurer, Pacific Coast Entomo¬

logical Society, Dept, of Entomology, California Academy of Sciences, Golden

Gate Park, San Francisco, CA 94118-4599.

Application for membership in the Society and changes of address should be

addressed to: Curtis Y. Takahashi, Membership Committee chair, Pacific Coast

Entomological Society, Dept, of Entomology, California Academy of Sciences,

Golden Gate Park, San Francisco, CA 94118-4599.

Manuscripts, proofs, and all correspondence concerning editorial matters (but

not aspects of publication charges or costs) should be sent to: Dr. John T. Sorensen,

Editor, Pan-Pacific Entomologist, Insect Taxonomy Laboratory, California Dept,

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Pacific Coast Entomological Society

OFFICERS FOR 1993

Susan B. Opp, President Kirby W. Brown, President-Elect

Paul H. Amaud, Jr., Treasurer Vincent F. Lee, Managing Secretary

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THE PAN-PACIFIC ENTOMOLOGIST (ISSN 0031-0603) is published quarterly by the Pacific

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THIS PUBLICATION IS PRINTED ON ACID-FREE PAPER.

PAN-PACIFIC ENTOMOLOGIST

69(2): 115-116, (1993)

A NEW LEPTOCONOPS {HOLOCONOPS) FROM BAJA

CALIFORNIA, MEXICO (DIPTERA: CERATOPOGONIDAE)

Gustavo R. Spinelli and Maria M. Ronderos

Instituto de Limnologia “Dr. Raul A. Ringuelet,”

Casilla de Correo 712,1900 La Plata, Argentina

Abstract.— Leptoconops ( Holoconops ) doyeni NEW SPECIES from Baja California, Mexico, is

described and male specimens are illustrated. It is compared with its closely related congeners,

L. (H .) bequaerti (KiefFer) and L. (//.) linleyi Wirth & Atchley.

Key Words. — Insecta, Ceratopogonidae, Leptoconops (.Holoconops ), Baja California

Biting midges of the genus Leptoconops Skuse are often extremely annoying,

bloodsucking pests in coastal or desert regions (Clastrier & Wirth 1978). Wirth

& Atchley (1973) reviewed the North American species of Leptoconops. They

provided a historical review and systematic accounts of the genus, as well as

diagnoses and key for recognition of the New World subgenera. They also rec¬

ognized 13 species, including the following five in the subgenus Holoconops Kief-

fer: L. {H.) belkini Wirth & Atchley, L. {H.) bequaerti (Kieffer), L. (H.) catawbae

(Boesel), L. (H.) kerteszi Kieffer, and L. (//.) linleyi Wirth & Atchley. Clastrier &

Wirth (1978), using new morphological characters in both males and females,

excluded L. kerteszi from the North American fauna and recognized 11 species

in a group that they named by custom the “ kerteszi complex .”

In this paper, we describe and illustrate male specimens of L. {Holoconops)

doyeni NEW SPECIES, from Baja California, Mexico, which closely resembles

the Circum-Caribbean species L. bequaerti and the Florida species L. linleyi. For

terminology see Clastrier & Wirth (1978).

Leptoconops {Holoconops) doyeni, NEW SPECIES

(Figs. 1-4)

Types. — Holotype, male, and one male paratype deposited in the California

Academy of Sciences, San Francisco, data: MEXICO. BAJA CALIFORNIA

NORTE: Bahia de Los Angeles, 18 Apr 1974, J. T. Doyen. Paratype, data: same

as holotype, 1 male deposited U.S. National Museum of Natural History, Wash¬

ington, D.C. Paratype, data: same as holotype, 1 male deposited in the Museo de

La Plata, Argentina.

Description.—Adult Male. Wing length 1.38 (1.27-1.50) mm, breadth 0.43 (0.39-0.47) mm (n =

3). Head. Dark brown. Antenna with dense plume; lengths of flagellomeres 11-13 in proportion of

9-16-53 (Fig. 1); pubescence present on flagellomeres 12-13. Palpus (Fig. 2) dark brown, segments 1-

2 paler; lengths of segments in proportion of 10-8-25-21; third segment with median sensory pit not

very deep containing small pore; sensory setae apparently absent. Thorax. Dark brown; 3 posterolateral

setae. Legs dark brown, tarsi pale brown; basitarsi of fore leg with (2-4-2) x 4 dark spines; mid leg

(2-2-2) x 2, (2-3-2) x 1; hind leg (0-4-1) x 4; basal setae of fifth tarsomere erect or erect curved;

tarsal claws mixed in fore and mid legs, simple in hind leg. Wing with membrane infuscated; costal

setae short (23-25), leaving a few voids at base of wing. Halter dark brown. Genitalia (Fig. 3). Ninth

tergum slightly broader than long, tapering posteriorly with marked caudal modification into trilobed

structure; single visible subapical seta. Gonocoxite stout, with conspicuous ventromedian lobe that is

Vol. 69(2)

116

THE PAN-PACIFIC ENTOMOLOGIST

Figures 1-4. Leptoconops ( H .) doyeni NEW SPECIES, male. Figure 1. Flagellomeres 11-13. Figure

2. Palpus. Figure 3. Genitalia. Figure 4. Tip of gonostylus.

darkly pigmented posteriorly; gonostylus 0.7 x length of gonocoxite, basal one-half broad with pair

of strong setae, distal one-half narrowed to sclerotized pointed apex, subterminal spine stout (Fig. 4).

Aedeagus represented by pair of narrow, separated, strongly sclerotized sclerites located between

swollen basal portion of gonocoxites, not extending beyond them. Parameres with stout, strongly

sclerotized basal arms; distal portion fused in H-shaped piece, distal ends stout, each pointed anteriorly

and with 2 mesally directed teeth.

Female. — Unknown.

Diagnosis. —Leptoconops doyeni NEW SPECIES is a dark brown species that

is very similar to L. bequaerti and L. linleyi, from which it can be distinguished

by its larger size, infuscated wing membrane, gonostylus with stronger setae, and

aedeagus represented by two separated pieces (distally fused in L. bequaerti and

L. linleyi ).

Distribution. — Restricted to the type-locality.

Etymology. — This species is named in honor of John T. Doyen, who collected

the type-series.

Material Examined.—See types.

Acknowledgment

We thank Willis W. Wirth for the critical review and suggestions on the manu¬

script.

Literature Cited

Clastrier, J. & W. W. Wirth. 1978. The Leptoconops kerteszi complex in North America (Diptera:

Ceratopogonidae). USD A Tech. Bull., 1573: 1-58.

Wirth, W. W. & W. R. Atchley. 1973. A review of the North American Leptoconops (Diptera:

Ceratopogonidae). Texas Tech. Univ., Grad. Stud., 5: 1-57.

Received 22 October 1991; accepted 28 December 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 117-121, (1993)

GROUP FORAGING FACILITATES FOOD FINDING IN A

SEMI-AQUATIC HEMIPTERAN,

MICRO VELIA AUSTRINA BUENO

(HEMIPTERA: VELIIDAE)

Steven E. Travers 1

Department of Biological Sciences, University of Kentucky,

Lexington, Kentucky 40506

Abstract.— Group living may evolve as a result of individuals finding food more quickly when

in the presence of others versus when alone. Food location by individuals may facilitate food

location by others in the group, and may increase mean search rate (food patches found/time)

relative to solitary foraging. I experimentally addressed the influence of group foraging on the

mean and variance in food-finding time (inverse of search rate) of a semiaquatic bug, Microvelia

austrina Bueno. Focal males and females were observed in the lab in two contexts: alone versus

in the presence of seven conspecifics. Food-finding time and movement rate were calculated for

29 focal animals in each context. Both the mean and variance in food-finding time decreased

significantly when focal animals foraged in groups versus alone. Faster microveliids had shorter

food-finding times. However, the decrease in food-finding times in groups is most likely due to

foraging animals being attracted to conspecifics that have located food, rather than movement

rate differences between foraging contexts. This is the first study to show search rate benefits to

group living in an insect.

Key Words. — Insecta, Hemiptera, Veliidae, group living, facilitation, foraging behavior

Group living can affect individual feeding rates (Pulliam & Caraco 1984). The

influence of group living on the mean and variance in the rate at which food, or

food patches, are found has received much experimental attention. If group living

has evolved in some species as a result of foraging advantages, then individuals

are expected to locate food less frequently when foraging alone versus in a group.

Individuals in groups often have higher mean and/or lower variance in search

rate (food patches found per unit time) than solitary individuals. These patterns

have been demonstrated experimentally in birds (Krebs et al. 1972, Brown 1988)

and fish (Pitcher et al. 1982). However, very few experimental studies have ex¬

amined the effects of group living on search rate in invertebrates (but see Rypstra

1989, Uetz 1988).

The semi-aquatic insect Microvelia austrina Bueno (Veliidae) is commonly

found clustered in groups of up to 100 individuals (Travers & Sih 1991) on the

surface of stream pools. They are opportunistic feeders on floating soft-bodied

organisms, such as anopheline larvae and muscid flies (Anderson 1982), and will

collectively feed on large items (personal observation). I conducted an experiment

on field-caught microveliids to test the predictions that: (1) foraging in groups,

versus alone, decreases both the mean and variance in time until a food item is

found (hereafter food-finding time); and (2) the food-finding time of an individual

is a function of the individual’s movement rate (number of moves per unit time).

'Current address: Department of Biological Sciences, University of California, Santa Barbara, Cal¬

ifornia 93106.

118

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Materials and Methods

Adult M. austrina were collected from a second order stream, 30 km south of

Lexington, Kentucky, and maintained in the laboratory for four days prior to

experimental trials. All animals were fed frozen fruit flies (Drosophila melano-

gaster Meigen) ad libitum up until 48 hours prior to the experiment. Twenty-four

hours prior to the experiment, focal males and females were isolated and marked

on the pronotum with a fine, red powder.

I measured the food-finding times of focal individual microveliids foraging in

two separate contexts: alone and in the presence of seven conspecifics of the same

sex. The sexes were tested separately to prevent mating, which would reduce the

number of animals searching for food. Fifteen focal males and fourteen focal

females were monitored in both treatments (solitary and group). Seven of the

males and females were monitored in the solitary treatment first (SG). The other

eight males and seven females were monitored in the group treatment first (GS).

Individuals were randomly assigned to GS or SG sequences.

All experimental trials were conducted in a plastic tub (19 x 30 cm) filled to

a depth of 4 cm with tap water. To prevent microveliids from detecting surface

vibrations that are associated with the introduction of food, all experimental

animals were placed on one side of an aluminum foil barrier while two frozen,

adult fruit flies were placed 7 cm apart on the other side of the barrier. Trials

began when I lifted the barrier. The following information was recorded with a

hand-held tape recorder during a trial: (1) time of trial initiation, (2) time of food

location by the focal individual, and (3) the number of movements by the focal

individual (microveliids move in a saltatory fashion with discrete starts and stops).

Trials were terminated after the focal animal found the first fly. I then calculated:

(1) the time required for each focal individual to find food when in a group versus

when alone, (2) the overall movement rate (number of moves per second) of focal

individuals while foraging alone, and (3) movement rates before and after food

discovery by a conspecific in group trials.

To compare food-finding times in solitary and group treatments, I used a one-

tailed paired Ftest because I had the a priori expectation that food-finding times

for individuals in groups would be lower than that of the same individuals when

alone. The variance in food-finding time was compared between treatments using

a F-ratio test. To test for effects of gender or trial sequence (SG or GS), I conducted

two-way analysis of variance (ANOVA) on food-finding times and movement

rates of focal animals (when alone, in a group, before versus after food discovery

by a conspecific). All values for ANOVAs were log-transformed to reduce het-

eroscedasticity.

Individuals varied considerably in food-finding time. To test the hypothesis

that more active foragers find food sooner, I regressed food-finding time against

movement rate in the same trial. I pooled the data for all analyses because in

most cases there were no significant gender or sequence effects (although after

food discovery females moved more frequently than males: F = 8.96, P = 0.009).

Results

Group foraging significantly reduced the food-finding time of focal animals by,

on average, 55.7% (x ± SD: solitary trials = 243.8 ± 58.3 sec, group trials =

107.9 ± 14.7 sec; paired Mest: t = 2.21, P = 0.02). Movement rate was signifi-

1993

TRAVERS: GROUP FORAGING IN MICROVELIA

119

cantly, negatively related to food-finding time when animals foraged alone (r 2 =

0.59, df = 28, P = 0.0007) and in groups (r 2 = 0.372, df = 28, P = 0.047); i.e.,

less active animals took longer to find food. Focal animals also showed significantly

lower variances in food-finding time when foraging in groups versus alone ( F-

ratio test: F = 15.7, P = 0.0001).

Foragers were significantly more active when foraging alone than when foraging

in a group (mean moves/sec ± SD: solitary trials = 0.66 ±0.1, group trials =

0.50 ± 0.02; paired /-test: t = 3.02, P = 0.005). Male movement rate did not

differ significantly before versus after food discovery (paired /-test: / = 0.13, P =

0.90). Females showed a nearly significant tendency to move faster following food

discovery (/ = 2.20, P = 0.06).

Discussion

This study is the first to address the effects of group foraging on foraging success

in an insect. As has been the case for many vertebrates, the mean and variance

in food-finding time were lower for foragers in groups. On average, M. austrina

thus enjoyed group benefits in search rate.

The search rate of microveliids depends in part on the rate at which they are

moving. Interestingly, despite a negative relationship between an individual’s

movement rate and food-finding time within both group and solitary treatments,

focal animals (1) had lower movement rates when in groups than when alone and

(2) found food sooner when in groups. This apparent contradiction is most likely

due to an increased proportion of movements being directed towards food items

for focal microveliids in groups relative to those foraging alone. Foraging mi¬

croveliids quickly responded to conspecifics that located food by moving in the

direction of the feeding animal(s). In 20 out of 29 (69%) group foraging trials, the

focal animal arrived at the food item after a conspecific. This interaction, termed

“local enhancement,” whereby individuals intentionally or unintentionally com¬

municate the location of food to others (Krebs et al. 1972, Pitcher et al. 1982),

may rely on surface waves created by actively feeding microveliids. Thus, despite

the fact that microveliids in group contexts move less frequently per time unit

relative to when alone, a larger proportion of the moves are towards food because

of cues provided by successful microveliids; this results in lower food-finding

times. Within each one of these foraging contexts, faster animals locate food

sooner.

A likely mechanism for the location of successful foragers is detection of vi¬

brations through the surface tension of water. Wilcox (1979) found that rapid

movement of tarsi by water striders (Gerris remigis Say) on the water surface

effectively communicates gender of one male to another male. Successful mi¬

croveliids increased the movement rate of their tarsi upon finding food. Further¬

more, other foraging microveliids seemed to move in the direction of the successful

microveliid after its discovery. An intriguing possibility in this scenario is that

the communication of food whereabouts is intentional, suggesting altruism on the

part of successful foragers. Given a few assumptions (see Trivers 1971), intentional

communication between all members of a population should evolve if the decrease

in food-finding time associated with group foraging translates into fitness benefits.

An individual can only gain the benefit of decreased food-finding times by co¬

operating with conspecifics that signal. However, once that individual cooperates

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Vol. 69(2)

(signals), the cost of cooperation (sharing its find) will be outweighed by the benefit

of shorter mean food-finding times in the long run, improving the individual’s

fitness.

Variance in food-finding time was lower in group foraging, as has been observed

in other animals (Krebs et al. 1972, Brown 1988, Pitcher et al. 1982). Because

my main goal in this experiment was simply to test for this relationship, I have

no further data on whether microveliids switch to solitary foraging (risk-sensitive)

when starved, as predicted by theory (Caraco 1980). Further experiments on this

question may illuminate some of the selective forces responsible for the evolution

of group living in this species.

The rate at which food items are encountered is only one of several components

influencing a forager’s rate of energy gain. Although an individual microveliid

may find more food items per unit of time when in a group, the individual may

gain less energy/time than a solitary forager because grouped microveliids are

forced to share prey with conspecifics (see Clark & Mangel 1986). On the other

hand, there may be a premium on finding food quickly because of behavioral

tradeoffs between foraging, predation risk and mating behavior. Predatory sunfish

(Lepomus cyanellus Rafinesque) and water striders (Gerris remigis ) are known to

disrupt the mating behavior (Travers & Sih 1991) and alter habitat use (Sih 1988)

of Micromelia austrina. Thus, longer food-finding time for solitary individuals may

lead to mating and predation costs that outweigh the benefits of feeding alone.

Faster location of food resources may also be advantageous despite reduced per

patch reward given the ephemeral nature of acceptable food floating downstream.

Further experiments examining energy gains of individual microveliids foraging

in groups and in field situations will be informative.

Acknowledgment

I thank Andy Sih, Phil Crowley, Craig Sargent, Roland Knapp, and Susan Mazer

for their useful comments on this manuscript. Data collection in this study would

have been impossible without the flawless assistance of Beth Karson.

Literature Cited

Anderson, N. M. 1982. The semiaquatic bugs. Scandinavian Science Press Ltd., Klampenborg,

Denmark.

Baker, C. M., C. S. Belcher, L. C. Deutsch, G. L. Sherman & D. B. Thompson. 1981. Foraging

success in junco flocks and the effects of social hierarchy. Anim. Behav., 29: 137-142.

Brown, C. R. 1988. Enhanced foraging efficiency through information centers: a benefit of coloniality

in cliff swallows. Ecology, 69: 602-613.

Caraco, T. 1980. On foraging time allocation in a stochastic environment. Ecology, 61: 119-128.

Clark, C. W. & M. Mangel. 1986. The evolutionary advantages of group foraging. Theor. Popul.

Biol., 30: 45-75.

Krebs, J. R., M. H. MacRoberts & J. M. Cullen. 1972. Flocking and feeding in the great tit Par us

major—Sin experimental study. Ibis, 114: 507-530.

Pitcher, T. J., A. E. Majurran & I. Winfield. 1982. Fish in larger shoals find food faster. Behav. Ecol.

Sociobiol., 10: 149-151.

Pulliam, H. R. & T. Caraco. 1984. Living in groups: is there an optimal group size? pp. 122-147.

In Krebs, J. R. & N. B. Davies (eds.) Behavioural ecology (2nd ed.). Blackwell, Oxford.

Rypstra, A. L. 1989. Foraging success of solitary and aggregated spiders: insights into flock formation.

Anim. Behav., 37: 274-281.

Sih, A. 1988. The effects of predators on habitat use, activity and mating behaviour of a semi-aquatic

bug. Anim. Behav., 36: 1846-1847. ;

1993

TRAVERS: GROUP FORAGING IN M1CROVELIA

121

Travers, S. E. & A. Sih. 1991. The influence of starvation and predators on the mating behaviour

of a semi-aquatic insect, Microvelia austrina. Ecology, 72: 2123-2136.

Trivers, R. 1971. The evolution of reciprocal altruism. Q. Rev. Biol., 46: 35-57.

Uetz, G. W. 1988. Group foraging in colonial web-building spiders: evidence for risk-sensitivity.

Behav. Ecol. Sociobiol., 22: 265-270.

Wilcox, R. S. 1979. Sex discrimination in Gerris remigis: role of a surface wave signal. Science, 206:

1325-1327.

Received 21 November 1991; accepted 25 November 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 122-132, (1993)

FILES AND SCRAPERS: CIRCUMSTANTIAL EVIDENCE FOR

STRIDULATION IN THREE SPECIES OF AMBLYCERUS,

ONE NEW (COLEOPTERA: BRUCHIDAE)

John M. Kingsolver , 1 Jesus Romero N., 2 and Clarence Dan Johnson 2

1 Systematic Entomology Laboratory, USD A,

Room 1, Building 004, BARC West,

Beltsville, Maryland 20705

department of Biological Sciences,

Northern Arizona University,

Flagstaff, Arizona 86011-5640

Abstract. — Amblycerusstridulator NEW SPECIES, A. pollens (Sharp) and A. eustrophoides (Schaef¬

fer) have in common a fusiform node with transverse striations on the metepistemum and an

apical tooth on the metafemur. The fusiform node (file) and the apical tooth (scraper) may be

stridulatory organs. Similar structures in criocerine Chrysomelidae are discussed and compared

to the bruchids. Amblycerus eustrophoides and A. pollens are redescribed. Amblycerus stridulator

NEW SPECIES is described from Mexico. The species differ in the sclerites in the internal sac,

patterns of pubescence, and the position of the fusiform node on the metepistemum.

Key Words. —Amblycerus, taxonomy, Mexico, A. stridulator, A. pollens, A. eustrophoides, Bru-

chidae, stridulation

This paper describes a new species and redescribes two named species of Am-

blycerus that have structures that may be stridulatory organs. To our knowledge,

no bruchid is known to stridulate nor to have structures that resemble those

reported here.

Our studies were stimulated by the observation by Kingsolver (1970) that

Amblycerus eustrophoides (Schaeffer) has a unique structure for bruchids: a fusi¬

form node with transverse striations on the metepistemum. He hypothesized that

this structure “was apparently a stridulatory mechanism” when mbbed against a

spine on the ventral margin of the metafemur. Thus, the stmcture on the metepi¬

stemum may be a stridulatory file and the spine on the metafemur a scraper

(plectrum).

Amblycerus stridulator NEW SPECIES, described here, and A. pollens (Sharp)

and A. eustrophoides, redescribed here, are the other two species of Amblycerus

known to have these structures. No living specimens have been analyzed, so we

do not know whether these structures are, in fact, stridulatory in function. We

believe, however, that it is very important to present our accumulated morpho¬

logical data here for its heuristic value.

Amblycerus is a large genus with 102 described species (Kingsolver 1990) and

has a wide distribution, especially in the Neotropics.

Amblycerus eustrophoides (Schaeffer)

Spermophagus eustrophoides Schaeffer 1904: 228.

Amblycerus eustrophoides: Johnson 1968: 1268; Bottimer 1968: 1012; Kingsolver

1970: 4; Johnson & Kingsolver 1981: 410.

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KINGSOLVER ET AL.: STRIDULATION IN BRUCHIDS

123

Type.—Lectotype. Locality: FLORIDA. PALM BEACH Co.: Lake Worth; De¬

pository: U.S. National Museum of Natural History, Washington, D.C.; Schaeffer

1907: 293; Leng 1920: 306.

Redescription.— Length (pronotum-elytra) 4.9-6.5 mm. Width 3.1-4.0 mm. Maximum thoracic

depth 2.3-3.1 mm.

Male.—Integument Color. Body uniformly red to dark red; frons and clypeus sometimes dark brown;

eyes silvery or black.

Vestiture. Body covered with silvery gray setae; on elytron each foveola with 1 brown seta; pygidium

with narrow median line of setae. Structure. Head. Elongated, densely punctulate; frons with median

impunctate line extending from frontoclypeal suture to middle of frons. Eye ovoid, cleft to 0.2 x its

length by ocular sinus; medial margin of eye with row of long, golden setae. Segment 1 of antenna

about 2x longer than second; third segment 1.8 x longer than second; remaining segments more or

less with proportions as first; antenna reaching middle area of hind coxa. Clypeus covered with

punctures. Labrum with few punctures. Prothorax. Disk subcampanulate, median basal lobe weakly

convex, basal margin with carina. Dorsal surface of pronotum punctulate with deep foveolae scattered

on surface; lateral carina extending to anterior comer, not reaching cervical sulcus; cervical sulcus

extending to midline, with 3 cervical setae. Prostemum flat, constricted between coxae, carinate

laterally; proepistemum with foveolae on anterior half. Mesothorax and Metathorax. Scutellum slightly

elongate, finely punctulate, 1.5 x as long as wide, lateral margins straight, strongly tridentate at apex.

Elytron 2.2 x as long as broad; striae regular, weakly impressed and deeply punctulate; strial intervals

finely punctured. Mesostemum tongue-like in basal area, finely punctulate, with a mesal sulcus for

reception of posterior area of prostemum. Mesepistemum and mesepimeron finely punctulate, without

foveolae. Metastemum punctulate with few foveolae on mesal region; longitudinal suture of meta-

stemum 0.4 x as long as sternum; antecoxal suture of metastemum interrupted before reaching median

sulcus, bending caudad and reaching posterior margin near mesal area of metastemum. Metepistemum

punctulate with shallow to deep foveolae over surface; metepistemal sulcus forming right angle with

transverse axis slightly curved and reaching lateral margin of metepistemum, longitudinal axis wider,

fusiform and striate transversely to form a “file” (Fig. 1). Surface of hind coxa punctulate, densely

setose, and foveolate on lateral 0.66, remaining 0.33 polished, impunctate, with a small cluster of

punctures near trochanteral insertion; both foveolae and cluster of punctures proximate; metafemur

punctulate, without foveolae, with angulate tooth on ventral margin (Fig. 2); lateral tibial calcarium

slightly curved, 0.55 x as long as basitarsus; mesal calcarium 0.6 x as long as lateral calcarium.

Abdomen. Sterna finely punctulate with few foveolae on lateral surface, with few, long setae on mesal

region of each; fifth sternum emarginate at apex; pygidium with terminal margin rounded or slightly

truncate, surface finely punctulate, with scattered foveolae. Genitalia (Figs. 3, 4). Median lobe slightly

constricted on lateral margins; ventral valve acuminate at apex, arcuate in lateral view; dorsal valve

narrow and deeply concave at base; armature of internal sac with 2 basal, subtriangular sclerites with

dorsal surfaces finely dentate; 2 median blades with 0.5 of dorsal surface dentate and wishbone-shaped

sclerite; 2 irregular, apical, small sclerites; internal sac lined with many fine spinules. Lateral lobes

cleft to 0.2 x their length (Fig. 4).

Female.— Similar to male, except fifth abdominal sternum not emarginate.

Host plants.— Drypetes laterifolia (Swartz): Kingsolver 1970: 475.

Distribution.— Costa Rica, Cuba, Mexico, United States.

Discussion.—Amblycerus eustrophoides is discussed under A. stridulator.

Material Examined.—See type. FLORIDA. DADE Co.: Matheson Hammock, Coral Gables, 20

Jun 1965, L. & C.W. O’Brien Collectors. MEXICO. TAMAULIPAS: Hda. Santa Engracia, May-Jun

1936, M. McPhail, Collector, reared from “huilotillo.”

Amblycerus pollens (Sharp)

Spermophagus pollens Sharp 1885: 495.

Spermophagus subflavidus Pic 1902: 172 (Type. Locality: “Bresil”; Depository:

Museum d’Histoire Naturelle, Paris); Kingsolver 1976: 151.

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Vol. 69(2)

Figures 1-2. Amblycerus eustrophoides. Figure 1. Scanning electron micrograph (SEM) of metepi-

stemum showing “file.” Figure 2. SEM of ventromesal margin of hind leg showing “scraper” or tooth

on ventral surface.

1993

KINGSOLVER ET AL.: STRIDULATION IN BRUCHIDS

125

Figures 3-4. Amblycerus eustrophoides. Male genitalia: Figure 3. Median lobe, ventral view. Figure

4. Lateral lobes, ventral view.

Amblycerus pollens : Blackwelder 1946: 763, Kingsolver 1976: 151, Kingsolver

1980: 238, Johnson & Kingsolver 1981: 410.

Amblycerus subflavidus: Blackwelder 1946: 763, Kingsolver 1976: 151.

Type. — Spermophagus pollens. Type Locality: “British Honduras, Belize”; De¬

pository: British Natural History Museum, London).

Redescription.— Length (pronotum-elytra) 7.8-8.7 mm. Width 4.5-5.3 mm. Maximum thoracic

depth 3.5^4.0 mm.

Male.—Integument Color. Pronotum and elytra red-brown, narrow, dark line on lateral margin of

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Vol. 69(2)

Figures 5-6. Amblycerus pollens. Figure 5. a. Metepistemum, b. file and c. metacoxa. Figure 6.

Hind leg with short “scraper.”

elytron; rest of the body dark brown or black; elytron, abdomen and pygidium may be yellow in some;

eyes silvery or shiny black. Vestiture. Pronotum and pygidium covered with orange setae; elytron

clothed with very fine orange setae, elytron with ten narrow, vague, longitudinal lines of white setae

in striae, very vague in specimens with a slightly yellow integument; rest of the body covered with

fine white pubescence, except the inner face of protibia clothed with golden setae. Structure. Head.

Subtriangular, with many fine punctures interrupted by large punctations; frons with median im-

punctate line, without evident median carina. Eye width slightly more than base of frons, slightly

more narrow at apex; eye cleft 0.20 x its length by ocular sinus. Antennal segments with small foveolae;

first segment of antennae 2.6 x longer than second; third segment 2x longer than second; remaining

segments about same length as first segment; antenna reaching anterior margin of hind coxa. Clypeus

covered with punctures, except small fringe on apical margin. Labrum covered with fine punctures.

Prothorax. Disk subcampanulate, median basal lobe weakly convex, basal margin with carina. Dorsal

surface of pronotum finely punctulate, with 3 longitudinal lines of fine foveolae on each side; pronotum

with lateral carina reaching 0.25 distance to cervical sulcus; cervical sulcus extending dorsad almost

to dorsal midline; with 4 cervical setae; lateral margin of pronotum sinuate. Prostemum flat, finely

punctate, constricted between coxae, apical portion curved; proepistemum finely punctate with fo¬

veolae on anterior half. Mesothorax and Metathorax. Scutellum slightly elongate, finely punctulate,

with 2 weak sulci, tridentate apically. Elytron 2.7 x as long as broad; striae regular, moderately

impressed, deeply punctate, principally on anterior 0.33; strial intervals with many fine punctations.

Mesostemum linguiform, with mesal sulcus for reception of prostemal process; mesepistemum and

mesepimeron finely punctate, without foveolae; metastemum finely punctate, with few deep foveolae;

longitudinal suture of metastemum 0.33 x as long as sternum; antecoxal suture of metastemum

interrupted before reaching median sulcus, bending caudad and reaching posterior margin near mesal

area of metastemum. Metepistemum punctulate, without evident foveolae; metepistemal sulcus form¬

ing right angle, with the transverse axis curved and reaching lateral margin of metepistemum, Ion-

1993

KINGSOLVER ET AL.: STRIDULATION IN BRUCHIDS

127

Figures 7-9. Amblycerus pollens. Male genitalia: Figure 7. Median lobe, ventral view. Figure 8.

Sclerite of internal sac. Figure 9. Lateral lobes, ventral view.

gitudinal axis fusiform, with fine, transverse striations to form fusiform node with transverse striations

(Fig. 5). Hind coxa punctate, foveolate, lateral 0.66 and posterior margin densely setose, medial 0.33

polished, impunctate, except for cluster of punctures near trochanteral insertion (Fig. 5); metafemur

finely punctate, pubescent with a small angulate tooth on ventral margin (Fig. 6); inner face of metafe¬

mur densely punctulate with cluster of foveolae on mesal portion; metatibia finely punctulate with

scattered foveolae; lateral tibial calcarium curved, 0.8 x as long as basitarsus, mesal calcarium 0.4 x

as long as lateral calcar. Abdomen. Sterna finely punctate with few foveolae on lateral areas; fifth

sternum slightly emarginate at apex; pygidium with terminal margin rounded, surface finely punctate

with deep foveolae. Genitalia (Figs. 7,8,9). Median lobe slightly constricted on lateral margins; ventral

valve acuminate at apex; dorsal valve narrow, about 0.5 x as wide as apex of median lobe, apex gently

rounded; in ventral view base of internal sac with armature of two, spiny elliptic plates, 20-25 verrucae;

median moderate-sized, acuminate sclerite, and two blade-shaped sclerites with 0.5 of dorsal surfaces

serrate; middle and apex of internal sac lined with many fine spinules; triangular gonopore duct sclerite

at apex. Lateral lobes cleft to about 0.3 their length (Fig. 9).

Female. — Similar to male except apical margin of fifth abdominal sternum truncate.

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Vol. 69(2)

Host Plants.— Unknown.

Distribution. — Belize, Guatemala, Costa Rica, Venezuela, French Guiana, Bra¬

zil.

Discussion. —Amblycerus pollens is discussed under A. stridulator.

Material Examined.—See type. COSTA RICA. PUNT ARENAS: Puntarenas, 28 May 1971, J. Fox,

collector. Bresil.

Amblycerus stridulator, NEW SPECIES

Type Series.— MEXICO. JALISCO: Estacion de Biologia, Chamela, 17 Feb

1985, ex seeds Caesalpinia sclerocarpa Standley, T.H. Atkinson (THA 167). Al¬

lotype and 4 paratypes, same data. Other paratypes: Same locality as holotype

but April 1980, ex seeds Caesalpinia sclerocarpa, A. Pescador; same locality but

17 Jul 1987, R. Tumbow. SINALOA: 10.8 km (6 mi) N Mazatlan, nr. beach, 26

Feb 1973, reared seeds #215-73, Caesalpinia sclerocarpa, emerg. 15 Mar 1973,

C. D. Johnson. OAXACA: Port Guatulca, 3 Dec 1937, Zaca Exped. Acc. 37483.

COSTA RICA. PUNT.: Monteverde, 1400 m, 12-14 Aug 1987, 24 Aug 1987, H.

& A. Howden. VENEZUELA. LARA: 4 km N LaPastora, 2-3 Mar 1978, riparian

forest, J.B. Heppner. Holotype and paratypes deposited in the collection of the

Universidad Nacional Autonoma de Mexico, Mexico, D.F. Allotype and para¬

types deposited in the U.S. National Museum of Natural History, Washington,

D. C. Paratypes also deposited in the American Museum of Natural History, New

York; the H. & A. Howden collection, Ottawa, Ontario, Canada; the C. D. Johnson

collection, Flagstaff, Arizona; and the Departamento de Biologia, Universidade

Federal do Parana, Curitiba, Brazil.

Description. — Length (pronotum-elytra) 5.3-7.7 mm. Width 3.2—4.5 mm. Maximum thoracic depth

2.3-3.1 mm.

Male. — Integument Color. Body red-brown to piceous, eye black, antenna mostly piceous, metatibia

and metatibial spurs dark red. Vestiture. Mostly with gray setae but with scattered spots of red-brown

setae on pronotum and elytra; venter of body gray except slightly yellow along posterior border of

each abdominal sternum, and slightly yellow spots along lateral margin of abdomen; tarsal pads yellow;

pygidium with median line of gray setae. Structure. Head. Turbiniform, eyes strongly protuberant,

coarsely faceted, ocular sinus less than 0.2 x length of eye; frons narrowed toward frontoclypeal suture,

frontal carina obtuse, frons finely, densely punctate, clypeus more strongly punctate, labrum finely

punctate and setose along basal border, finely fringed on apical margin; basal antennal segment 3 x

length of second, segments 4-10 serrate, eleventh subelliptical; submentum coarsely punctate. Pro-

thorax. Pronotum nearly semicircular, perceptibly angulate at anterolateral comers, basal lobe shallow,

disk convex, somewhat depressed along base, surface finely foveolate, foveolae more dense on each

lateral 0.33 of disk, intervals minutely punctate; lateral margin carinate and arcuate; hypopleuron

concave; cervical sulcus extending from near anterior end of lateral carina to a point behind upper

margin of eye; cervical boss bisetose; prostemum Y-shaped, with shallow sulcus before procoxae,

intercoxal process flat, margins slightly constricted, apex bluntly attenuate. Mesothorax and Meta¬

thorax. Scutellum 2x as long as wide, constricted at middle, tridentate apically. Elytra 1.5x as long

as wide, depressed around scutellum, striae regular in course except base of fourth closer to third than

to fifth, sixth and seventh usually conjoined apically; striae moderately deep, regularly punctate,

interstices nearly flat. Mesostemum nearly vertical, apex abmptly bent caudad and channeled to receive

apex of prostemum; postmesocoxal sulci joined at midline and extending laterad to pleurostemal

suture; metepistemal parasutural sulcus extending to metacoxal cavity, abmptly bent at anterior end

and ending at elytral margin, metepistemal disk with arcuate stridulatory file extending anteriorly

from coxal cavity 0.75 x length of sclerite (Fig. 10). Metacoxal face sparsely, evenly punctate in middle

0.33, and with dense cluster of punctures near trochanteral fossa. Front and middle legs not modified;

metafemur with angulate tooth on ventromesal margin (Fig. 11), mesal face of tooth finely striate;

1993

KINGSOLVER ET AL.: STRIDULATION IN BRUCHIDS

129

Figures 10-11. Amblycerus stridulator. Figure 10. SEM of metepistemum showing “file.” Figure

11. SEM of ventromesal margin of hind leg showing “scraper” or tooth with many fine striations on

ventral margin.

lateral metatibial spur 2x as long as mesal spur. Abdomen. Sternum 5 nearly as long as remaining 4

together; sternum 5 broadly emarginate apically; pygidium nearly semicircular, disk densely, irregularly

microfoveolate. Genitalia (Figs. 12, 13, 14). Median lobe more than 3 x as long as wide; ventral valve

subtriangular, lateral margins concave; dorsal valve subelliptical, extending beyond apex of ventral

valve; internal sac armed with 3 types of paired sclerites: a pair of flat blades with serrate lateral

margins, a pair of large, falcate, thom-like sclerites with swollen bases, and a pair of irregularly twisted,

130

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(2)

Figures 12-14. Amblycerus stridulator. Male genitalia: Figure 12. Median lobe, ventral view. Figure

13. Sclerite of internal sac. Figure 14. Lateral lobes, ventral view.

densely spiny lobes; apex of sac membranous and plicate. Lateral lobes cleft to 0.26 their length,

Y-shaped, truncate and setose apically, median strap with minute, cylindrical sensillae (Fig. 14).

Female.— Similar to male except fifth sternum evenly rounded.

Diagnosis. —Amblycerus stridulator can be separated from A. pollens and A.

eustrophoides by its file, which is transverse to the metepistemal sulcus (see dis¬

cussion).

Host Plants. — Caesalpinia sclerocarpa Standley.

Distribution. — Mexico.

Etymology.— The name stridulator is a noun in apposition to Amblycerus. It

refers to the apparent stridulatory structures of this species.

Discussion

Systematics. — In addition to A. stridulator, A. eustrophoides and A. pollens have

a fusiform node with transverse striations (Figs. 1, 5) on the metepistemum and

an apical tooth on the metafemur (Figs. 2, 6). The species differ, however, in the

sclerites in the internal sac (Figs. 3, 7), patterns of pubescence, and the position

of the fusiform node on the metepistemum. Amblycerus stridulator is distinct

from A. pollens and A. eustrophoides as the latter two species are more similar to

1993

KINGSOLVER ET AL.: STRIDULATION IN BRUCHIDS

131

one another in external morphology (revisionary studies currently under way

indicate, however, that the three species are in different species groups). Ambly-

cerus pollens and A. eustrophoides have files that apparently are a modification

of the longitudinal axis of the metepistemal sulcus, and the tooth (scraper) on the

hind femur is not striate. The sclerites in the internal sac of both species are similar

in shape and number, especially the spiny subelliptic plates and the blade-shaped,

serrate sclerite. Also, the lateral lobes (Figs. 4, 9) do not have pads between their

apices.

The file of A. stridulator is transverse to the metepistemal sulcus (Fig. 10),

apparently originating as a modification of the metepistemum. The tooth on the

hind femur has fine striations over its entire surface (Fig. 11). The internal sac of

the male genitalia has only the blade-shaped serrate sclerites (Fig. 12) that are

similar to those in A. pollens and A. eustrophoides. The lateral lobes have a pair

of pubescent pads between them (Fig. 14). Unfortunately the host plants of A.

pollens are unknown. That A. stridulator feeds on Caesalpinia sclerocarpa (Fa-

baceae) and A. eustrophoides in Drypetes laterifolia (Swartz) (Euphorbiaceae) is

of significant value. Because A. pollens is more similar to A. eustrophoides increases

the possibility that A. pollens may feed in a Euphorbiaceae. This suggests that

two lines of development have occurred, with A. stridulator more distant from

the other two species in both morphology and host plant preferences.

Stridulation. — Because we have no evidence that these three species actually

produce sounds, we can do no more than hypothesize here. The “files” in our

scanning electron micrographs (Figs. 1,10) are remarkably similar to those in six

species of criocerine Chrysomelidae studied by Schmitt & Traue (1990). Bmchids

are very closely related to chrysomelids. Unlike the three bmchids, the sounds

produced by the chrysomelids were discovered long before the mechanism for

producing them. Schmitt and Traue hypothesized that the sounds produced by

the chrysomelids were similar to “disturbance sounds” of other insects because

they could not detect species-specific differences in sounds nor sexual dimorphism

of the stridulatory organs. They used oscillograms, frequency spectra and sona-

grams for their analyses. The files of the chrysomelids were located on “the last

perceptible abdominal tergite, the so-called pygidium, and adjoined the rostral

margin of the pygidium.” The plectra (scrapers) “were situated on the underside

of the elytra in the hind sutural angles.” Sounds were produced during contraction

of the abdomen.

Kingsolver (1970) observed that A. eustrophoides has a unique structure for

bmchids: a fusiform node with transverse striations on the metepistemum. He

hypothesized that this stmcture on A. eustrophoides “was apparently a stridulatory

mechanism” when mbbed against a spine on the ventral margin of the metafemur.

Thus, the structure on the metepistemum may be a file and the spine on the

metafemur a scraper (plectmm). Because three species of bmchids are now known

to possess what appear to be files and scrapers, we will begin a study shortly on

A. stridulator, the species whose hosts, and thus living specimens, are most ac¬

cessible.

Acknowledgment

We are grateful for partial support for this study from USDA Grants 12-14-

100-9187 (33), 12-14-100-9970 (33) and NSF Grant BSR88-05861 to CDJ.

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Literature Cited

Blackwelder, R. E. 1946. Checklist of the coleopterous insects of Mexico, Central America, the West

Indies, and South America. Vol. 4. Bull. U.S. Natl. Mus., 185: 551-763.

Bottimer, L. J. 1968. Notes on Bruchidae of America north of Mexico with a list of world genera.

Can. Entomol., 100: 1009-1049.

Johnson, C. D. 1968. Bruchidae type specimens deposited in United States museums, with lectotype

designations (Coleoptera). Ann. Entomol. Soc. Am., 61: 1266-1272.

Johnson, C. D. & J. M. Kingsolver. 1981. Checklist of the Bruchidae (Coleoptera) of Canada, United

States, Mexico, Central America and the West Indies. Coleopts. Bull., 35: 409-422.

Kingsolver, J. M. 1970. A synopsis of the subfamily Amblycerinae Bridwell in the West Indies, with

descriptions of new species (Coleoptera: Bruchidae). Trans. Am. Entomol. Soc., 96: 469-497.

Kingsolver, J. M. 1976. A new species of Amblycerus from Panama. Jour. Wash. Acad. Sci., 66:

150-151.

Kingsolver, J. M. 1980. Eighteen new species of Bruchidae, principally from Costa Rica, with host

records and distributional notes (Insecta: Coleoptera). Proc. Biol. Soc. Wash., 93: 229-283.

Kingsolver, J. M. 1990. New World Bruchidae past, present, future, pp. 121-129. In Fujii, K., A.

M. R. Gatehouse, C. D. Johnson, R. Mitchell & T. Yoshida (eds.). Bruchids and legumes:

economics, ecology and coevolution. Proceedings of the Second International Symposium on

Bruchids and Legumes (ISBL-2) held at Okayama (Japan), September 6-9, 1989. Kluwer Ac¬

ademic Publishers, Dordrecht, Boston, London.

Leng, C. W. 1920. Catalogue of the Coleoptera of America, north of Mexico. Sherman, Mount

Vernon, New York.

Pic, M. 1902. Description de coleopteres nouveaux. Bruchidae de l’Amerique meridionale. Le Na-

turaliste, 24: 172.

Schaeffer, C. F. A. 1904. New genera and species of Coleoptera. Jour. New York Entomol. Soc., 12:

197-236.

Schaeffer, C. F. A. 1907. New Bruchidae with notes on known species and list of species known to

occur at Brownsville, Texas, and in the Huachuca Mountains, Arizona. Mus. Brooklyn Inst.

Arts and Sci., Sci. Bull., 1: 291-306.

Schmitt, M. & Traue, D. 1990. Morphological and bioacoustic aspects of stridulation in Criocerinae

(Coleoptera, Chrysomelidae). Zool. Anz., 225: 225-240.

Sharp, D. 1885. Bruchidae. Biol. Centrali-Americana, Coleoptera, 5: 437-504, Tab. 36.

Received 21 November 1991; accepted 1 February 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 133-140, (1993)

SYNONYMY OF TWO GENERA OF CYNIPID GALL WASPS

AND DESCRIPTION OF A NEW GENUS

(HYMENOPTERA: CYNIPIDAE)

Robert J. Lyon

2120 Bristow Drive, La Canada-Flintridge, California 91011

Abstract.— The location and reexamination of the “lost” generatype of the cynipid genus Xys-

toteras Ashmead has made it possible to demonstrate that this genus is a junior synonym of

Phylloteras Ashmead NEW SYNONYMY. Two species, Phylloteras lyratum NEW SPECIES

and P. primum NEW SPECIES are described, and a key to the species of Phylloteras is included.

Euxystoteras campanulatum NEW GENUS AND NEW SPECIES, is described and compared

to other closely related genera.

Key Words.— Insecta, Cynipidae, unisexual female, monothlamous gall

Confusion has long existed as to the identities of two Ashmead genera: Phyl¬

loteras and Xystoteras. The type-species of Phylloteras, Biorhiza rubinus Gillette,

1888, was redescribed by Ashmead (1897a) as having toothed claws and 13-

segmented antennae. The type-species of Xystoteras, Xystoteras volutellae Ash¬

mead (1897b), was described as having simple claws and 14-segmented antennae.

On the basis of these characters the genera could not be confirmed. In cynipid

taxonomy, the presence or absence of a tooth on the tarsal claw is considered to

be of fundamental importance in separating major genera of the group. Lewis

Weld (personal communication) and others believed that Ashmead, in his de¬

scription, had erred in stating that X. volutellae had simple claws because no other

species in these closely related genera had simple claws. As a result, all of the

described species in these genera were considered to have toothed claws and were

separated only by the number of antennal segments.

When the William Beutenmuller collection of Cynipidae came to the National

Museum of Natural History in 1935, the “missing” X. volutellae type was found.

Ashmead’s label, host and host locality were on the pin, but it did not have a

type label on it; I have examined this specimen and found that it agrees with the

published description. However, a slide preparation, examined under high mag¬

nification, clearly shows the tarsal claws to be toothed. The antennae have 14

segments. I have concluded that this is the holotype and it has been so labeled.

Study of a series of Phylloteras rubinum (Gillette) shows the number of antennal

segments to be variable. Most specimens have 13 segments with the terminal

segment at least 1.5 x the length of the preceding segment. Some specimens,

however, have 14 segments and the terminal segment slightly shorter than the

preceding one. Therefore there no longer seems to be a valid reason to separate

the two genera. Xystoteras (November 1897) is proposed as a junior synonym of

Phylloteras (May 1897) NEW SYNONYMY. The concept of the genus must now

be modified: wings absent or rudimentary; antennae with 13 or 14 segments; tarsal

claws toothed; notauli absent or present only as traces; head massive, at least

0.5 x as long as broad, broader than the mesosoma; gena broadened behind the

eyes; metasoma compressed, knife-like, with all tergites visible along the dorsal

margin, longer than the head and mesosoma combined. The following Xystoteras

134

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(2)

species are transferred to Phylloteras : X. nigrum (Fitch), X. poculum (Weld), and

X. volutellae (Ashmead).

Weld (1926), believing that the type of Xystoteras volutellae had been lost,

erroneously designated a series of specimens, collected at Texarkana, Arkansas,

on Quercus lyrata Walt as lectotypes (sic!). These were widely distributed to

various museums. After he located the “lost” type, he (Weld 1952) acknowledged

the error and stated that the specimens from Texarkana represented a new species

that should be described. This was never done, however, so a description of this

new species is provided here.

Phylloteras

Phylloteras lyratum Lyon NEW SPECIES

(Fig. 1)

Types. — Holotype female. Paratypes: 20 females, ARKANSAS. MILLER Co.:

Texarkana, from galls on Quercus lyrata Walt, Oct 1917 emerged from rearing

19 Feb, 20 Mar, 23 May, 6 Apr, 14 & 21 Jun 1918. Holotype and 4 paratypes

in National Museum of Natural History, Washington, D.C.; 4 paratypes in Natural

History Museum of Los Angeles County.

Description.— Unisexual female. Black, fading in older specimens; antennae, legs and ventral spine

brown. Head (Fig. 1D) massive; from above, more than 0.5 x as long as broad, broader than mesosoma;

gena broadened behind eyes, nearly as high as broad in frontal view (Fig. 1C), appearing nearly circular

in outline; interocular space broader than high; malar space without a groove, 0.33 x length of the

eye; frons coarsely rugose with large, shallow punctures. Antennae with 14 segments. Scutum slightly

longer than broad, smooth, shining, punctate anteriorly but without notauli; wing rudimentary but

reaching nearly to end of scutellum (Fig. ID). Scutellum rounded behind, pubescent, with deep rough¬

ened area across base; disk punctate, raised, appearing “humped” in side view, 0.5 x length of me-

soscutum. Metasoma (Fig. 1 A) smooth, polished, all terga visible along dorsal curvature; compressed

laterally, appearing knife-like beyond second tergum. Ventral spine long, slender, sparsely pubescent.

Tarsal claw (Fig. IB) with short tooth. Length 1.5-2.2 mm (3c = 1.8 mm; n = 12).

Gall.— (Fig. IE) Tiny, 3.5 mm high, monothalamous gall, attached to undersides of leaf blades.

Developing galls covered with white bloom during growth, but lost at maturity. Larval cell occupies

gall base.

Diagnosis.— See Key

Host. — Quercus lyrata Walt.

Etymology. — This species is named after its host oak, Quercus lyrata.

Material Examined. —Type series.

Phylloteras prinum Lyon NEW SPECIES

(Fig. 2)

Types. — Holotype female. Paratypes: 4 females, VIRGINIA. FAIRFAX Co.:

East Falls Church, 17 Oct 1946, emerged from rearing cages 22 Jan 1948. Holotype

and 1 paratype female in the U.S. National Museum of Natural History, Wash¬

ington, D.C. Three paratypes in the Weld collection, which is in R. J. Lyon’s

possession.

Description. —Unisexual female. Ant-like, deep chocolate brown; head (Fig. 2D), massive, more

than 0.5 x as long as broad, wider than mesosoma; gena (Fig. 2C) slightly broadened behind eyes;

interocular space broader than high and coriaceous; frons punctate; malar space slightly less than 0.5 x

length of eye, without groove; antennae with 13 or 14 segments; scutum as broad as long, smooth,

1993

LYON: CYNIPID GENERA

135

Figure 1. Phylloteras lyratum NEW SPECIES. A. Metasoma, lateral view, showing shape of terga.

B. Tarsal claw with short tooth. C. Outline of head, frontal view. D. Head and mesosoma showing

wing and scutum without notauli. E. Monothalamous gall showing position of larval cell. F. Leaf of

Q. lyrata showing distribution of galls on leaf.

shining, without punctures or notauli but with indentations in position of lateral lines, posterior margin

slightly emarginate; wings rudimentary, extending almost to end of scutellum (Fig. 2D); scutellum

grooved at base, punctate, humped in side view, 0.5 x length of mesoscutum. Metasoma (Fig. 2A),

laterally compressed, knife-like, longer than head and mesosoma combined, all terga visible along

dorsal curvature; tip of ovipositor hooked; ventral spine slender, bare; tarsal claws (Fig. 2B) strongly

toothed. Length 1.45-2.2 mm (3c = 2.1 mm; n = 5).

Gall. — (Figs. 2E, 2F) Monothalamous, circular, flattened disk, 4 mm diameter, with depressed center.

136 THE PAN-PACIFIC ENTOMOLOGIST Yol. 69(2)

Figure 2. Phylloteras prinum NEW SPECIES. A. Metasoma, lateral view, showing shape of terga.

B. Tarsal claw with long tooth. C. Outline of head, frontal view. D. Head and mesosoma showing

rudimentary wing and lateral depressions on the scutum. E. Monothalamous gall showing position of

larval cell. F. Leaf of Q. prinus showing distribution of galls.

Larval Development.—The insects were in the larval stage September 1946, but adults did not

emerge until 22 Jan 1948.

Diagnosis.— See Key.

Host. — Quercus prinus L.

Etymology. — This species is named after its host oak.

Material Examined. — Type series.

1993

LYON: CYNIPID GENERA

137

Key to Species of Phylloteras

1. Wings 1 extending at least to middle of scutellum. 2

Wings represented only by small pads . 5

2(1). Wings reaching to metasoma; scutum 3 x length of scutellum; scutum

anteriorly deeply and conspicuously punctate. Small (3.5 mm) cylin¬

drical galls on underside of leaf of Quercus macrocarpa Michaux (Kan¬

sas) . P. volutellae (Ashmead)

- Wings not reaching beyond scutellum; scutum less than 3 x length of

scutum; scutum punctate or smooth . 3

3(2). Tarsal claws 2 with short tooth (Fig. IB); scutum smooth, without traces

of notauli or lateral grooves. Small (3.5 mm) cylindrical galls on un¬

dersides of leaves of Quercus lyrata (Arkansas) . P. lyratum Lyon

- Tarsal claws with long tooth (Fig. 2B); scutum with traces of notauli

and/or with lateral grooves . 4

4(3). Scutum punctate anteriorly, faint notauli visible near center; scutellum

punctate. Small (3.5 mm) depressed, spherical galls on underside of

leaves of Quercus alba L. (Virginia) . P. nigrum (Fitch)

Scutum and scutellum smooth, impunctate; no trace of notauli, but

grooved laterally (Fig. 2D). Small (4.5 mm) circular spangles on the

underside of leaves of Quercus prinus L. (Virginia) ... .P. prinum Lyon

5(1). Tarsal claw with long tooth; scutellum narrow in front, angled on sides

and wider behind, with 2 small foveae at base. Depressed, spherical

galls (2-3 mm) on underside of leaves of Quercus alba (Illinois, Mis¬

souri, New York and Virginia). P. rubinum Gillette

Tarsal claw with short tooth; scutellum not as above . 6

6(5). Mesonotum as long as broad, from above, circular in outline; scutellum

equal in length to scutum; scutum smooth, without traces of notauli.

Small (2.6 mm) cup spangles on underside of leaves of Quercus ari-

zonica, Q. grisea and Q. undulata (Arizona and New Mexico) .

. P. cupella Weld

- Mesonotum longer than broad, not circular in outline; scutellum less

than 0.5 x length of scutum . 7

7(6). Scutum 3x length of scutellum; scutum and scutellum smooth, im¬

punctate; head outline triangular in frontal view. Sigmoid-shaped galls

on underside of leaves of Quercus alba L. (Maryland, New York,

Virginia and District of Columbia. P. sigma Weld

- Scutum 2.5 x length of scutellum; scutum and scutellum punctate; head

oval in frontal view. Button-shaped spangles on underside of leaves

of Q. alba, Q. prinus and Q. prinoides (Connecticut, Indiana, Kansas,

Maryland, Missouri, New York, Virginia and District of Columbia)

. P. poculum (Osten Sacken)

1 Presence of rudimentary wings may be difficult to see because the wings are usually stuck to the

body or encased in membrane.

2 Tarsal claw traits should be determined with a compound microscope at 350-450 x.

138

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Figure 3. Euxystoteras campanulatum NEW SPECIES. A. Metasoma, lateral view, showing shape

of terga. B. Simple (edentate) tarsal claw. C. Head, frontal view. D. Head and mesosoma showing

punctate scutum and distinctive scutellar shape. E. Monothalamous gall, showing position of larval

cell. F. Leaf of Q. pungens showing distribution of galls.

E UXYSTO TERAS NEW GENU S

Type-Species. —Euxystoteras campanulatum Lyon NEW SPECIES

Description.— Generally similar to Phylloteras and Zopheroterus Ashmead 1897(b), except: tarsal

claws simple; lacking knob-like scutellar process; distinct malar groove absent.

Diagnosis. —Euxystoteras is separable from Phylloteras by its simple tarsal claws.

It is separable from Zopheroterus by its lack of a knobbed scutellum and a distinct

malar groove.

Material Examined.—Set Euxystoteras campanulatum NEW SPECIES.

1993

LYON: CYNIPID GENERA

139

Euxystotera campanulatum Lyon NEW SPECIES

Types. — Holotype female. Paratypes: 19 females, TEXAS. EL PASO Co.:

Franklin Mountains, El Paso, emerged from galls 21 Oct 1972. Holotype and 4

paratypes in the collection of the U.S. National Museum of Natural History,

Washington, D.C. Four paratypes each in collections of the California Academy

of Sciences and the Natural History Museum of Los Angeles County.

Description.— Unisexual female (Fig. 3). Wingless, ant-like, black, except dark brown legs; head

massive (Fig. 3D), more than 0.5 x as long as broad, broader than mesosoma; gena broadened behind

eyes (Fig. 3C); interocular area 2 x as wide as high and coriaceous; face sculptured, with numerous

white bristles; two short convergent ridges extending from antennal sockets toward clypeus; malar

space 0.5 x length of eye, striate and with traces of furrow; antennae with 13 or 14 segments; scutum

flattened (Fig. 3D), wider than long, with scattered bristles; notauli represented by several punctures;

scutellum arrow-head shaped, separated from scutum by 2 comma-like curving pits extending toward

median; bluntly pointed apex with sculptured ridges. Metasoma (Fig. 3A) higher than long, longer

than head and mesosoma combined, all terga visible along dorsal curvature. Ventral spine slender,

bare. Tarsal claws simple (Fig. 3B). Length 1.1-1.8 mm (5c = 1.55 mm; n = 20).

Gall. —(Figs. 3E, 3F) Small, campanulate cup, 5 mm diameter, 3 mm high; on lateral veins of upper

and lower leaf surfaces. Monothalamous, larval cell occupying base. Appear in late summer as tiny,

purple spangles that grow rapidly to reach maturity in October; mature galls red-brown; adults emerged

21 October.

Diagnosis.— This is the only species in the genus.

Host. — Quercus pungens Liebmann, an unusual little shrub oak that grows at

elevations of 3500-6000 ft on limestone cliffs of mountains at scattered locations

in Arizona, New Mexico and Texas. No cynipids or galls have previously been

described from this oak. Lewis Weld, in his field notes, made frequent reference

to it as a host oak; however, in later years, he (Weld 1960) indicated that he

misidentified the oak and that his “ Quercus pungens ” was actually Q. turbinella

Greene. A number of years ago, John Tucker, of the University of California at

Davis, located specimens of this oak in the Franklin Mountains at El Paso, Texas,

and indicated that an excellent opportunity to study the cynipid fauna existed. I

have made periodic visits to these montains since 1964 and have found that the

oaks were abundantly “galled” with both described and undescribed species.

Material Examined —Type series.

Acknowledgments

I thank John M. Tucker (University of California, Davis, California) for his

help in locating and identifying specimens of the oak Quercus pungens ; Arnold

Menke of the U.S. National Museum of Natural History, Washington, D.C. for

providing the type of Xystoteras volutellae and for helpful assistance with the

taxonomy; Roy Snelling, Los Angeles County Museum of Natural History) for

constructive comments during the writing of this paper.

Literature Cited

Ashmead, W. H. 1897a. Description of some new genera in the family Cynipidae. Psyche, 8:

67-69.

Ashmead, W. H. 1897b. Descriptions of five genera in the family Cynipidae. Canadian Entomol.,

29: 260-263.

Fitch, A. 1859. Fifth report on noxious insects of New York. Transactions, New York Agr. Soc.,

290: 781-784.

Gillette, C. P. 1888. Twenty-seventh annual report, State of Michigan Board of Agriculture.

140

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Weld, L. H. 1922. Notes on cynipid wasps with descriptions of new North American species. Proc.

U.S. National Museum, 61: 1-291.

Weld, L. H. 1926. Field notes on gall-inhabiting cynipid wasps with descriptions of new species.

Proc. U.S. National Museum, 68: 1-131.

Weld, L. H. 1944. New American cynipids from galls. Proc. U.S. National Museum, 95: 1-24.

Weld, L. H. 1952. Cynipoidea (Hym.) 1905-1950. Privately published by L. H. Weld.

Weld, L. H. 1959. Cynipid Galls of the Eastern United States. Privately published by L. H. Weld.

Weld, L. H. 1960. Cynipid Galls of the Southwest. Privately published by L. H. Weld.

Received 21 January 1992; accepted 3 March 1993.

PAN-PACIFIC ENTOMOLOGIST

69(2): 141-148, (1993)

EFFECTS OF INCORPORATING CHEMICAL LIGHT

SOURCES IN CDC TRAPS: DIFFERENCES IN THE CAPTURE

RATES OF NEOTROPICAL CULEX, ANOPHELES

AND URANOTAENIA (DIPTERA: CULICIDAE ) 1

Edward Rogers, 2 L. Lance Sholdt, 3 and Roberto Falcon 4

2 Villa Grande, California 95486-0114

3 Department of Preventive Medicine and Biometrics,

Uniformed Services University of the Health Sciences,

Bethesda, Maryland 20814-4799

department of Entomology, Naval Medical Research Institute,

Detachment Lima Peru, APO Miami, Florida 34031-0008

Abstract.— Differential attraction of mosquitoes to chemical and incandescent light sources was

compared using battery operated suction traps placed in a tropical lowland forest. Females of

Culex adamesi Sirivanakam, Cx. amazonensis (Lutz), Cx. corniger Theobald, Cx. declarator

Dyar & Knab, Anopheles mattogrossensis Lutz & Neiva, Aediomyia squamipennis (Lynch),

Mansonia amazonensis (Theobald), TJranotaenia apicalis Theobald, and Ur. geometrica Theo¬

bald were significantly attracted to chemically produced light. Light sources influenced the num¬

ber of species attracted, the time (trap-nights) necessary to detect them, and the numbers of

specimens collected per species.

Key Words.— Insecta, Aediomyia, light traps, mosquitoes, Mansonia, phototaxis

Data from light traps are subject to several systematic errors, or biases, which

can complicate the interpretation of mosquito surveys. An important source of

bias is the unequal phototactic responses of mosquitoes to different wavelengths

and intensities of light. Because species do not respond alike, light trap collections

may not approximate true species’ abundances proportional to one another in

nature, let alone their relative attraction to man (Huffaker & Back 1943). This

can undermine the purpose of mosquito collections and affect survey time and

labor costs.

Although phototactic responses present pitfalls in data interpretation, they do

offer valuable opportunities to improve sampling regimes. Whether the intent is

to capture many species of a fauna or many individuals of one species, judicious

selection of an attractant can increase capture rates and shorten survey time.

The present study reintroduces a neglected method for quantifying losses and

gains in efficiency produced by light trap attractants (Gaufin et al. 1956). In the

process, some useful but seldom employed analysis techniques are examined for

their value in pilot studies. Chemical light sticks are used as attractants, because

a variety of them have recently become available commercially, and their portabil¬

ity may soon bring them into popular entomological use.

1 The opinions and assertions contained herein are the private ones of the authors and are not to

be construed as official or as reflecting the views of the U.S. Department of the Navy or of the naval

service at large.

142

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Methods and Materials

Testing Response to Light. — Data for testing responses were collected in a Latin

square design of CDC light traps. Trap sites were located 20-50 m apart along

the forest perimeter of the grounds of the Naval Hospital in Iquitos, Loreto

Department, Peru. Treatments were five chemical light sticks (yellow, green, blue,

white, and red; Cyalume®, American Cyanamid Company, One Cyanamid Plaza,

Wayne, New Jersey 07470), an incandescent bulb (type CM49), and a control (a

trap operating without light).

Treatments were assigned randomly to traps. Sticks (one per trap) were secured

over the intake vents of CDC-style battery operated downdraft light traps (Model

CDC-4; Hausherr’s Machine Works, Old Freehold Road, Toms River, New Jersey

08753) from which the light bulbs were removed. Traps remained in place at

sites, and sticks were switched each night, until the fauna of each site had been

sampled once with each treatment.

The manufacturer’s estimates of light duration were 12 hours (yellow, green,

and red sticks) and 8 hours (white and blue). Traps were set at 1730 h and emptied

at 0900; they ceased emitting blue and white light at 0130, but continued to emit

red, green, and yellow until 0530, and incandescent light until 0900. Traps were

operated on seven consecutive rainless nights in March 1989.

Female mosquitoes from light collections were identified to species and counted.

Counts of common (n > 40) species were examined in separate Friedman tests,

one test per species. Test hypotheses were, H 0 : Treatments attracted equal numbers

of females; H x : At least one treatment attracted more females than at least one

other. The Friedman test statistic, T2, was computed according to formulae cited

by Conover (1980) to approximate the F distribution. This statistic was then used

to calculate the minimum rank sum difference for multiple a posteriori compar¬

isons among treatments, as detailed in Conover (1980).

Sampling Efficiency. — The March experiment on light response was replicated

in several different sites in the same forest during June, October, and January,

using only red, blue, green and yellow as treatments. Efficiency estimates were

then derived by analyzing these replicates jointly with data from the March col¬

lection (25 sampling nights total). Analysis was based only on species that were

present in all four months and had shown significant phototaxis in March testing.

Sampling efficiency was defined as the average rapidity with which species were

discovered in the traps. This was inspected graphically by plotting changes in a

statistic termed P k by Gaufin et al. (1956). P k measured the average probability

of collecting a species not collected previously, by each treatment on each suc¬

cessive night. To compute P h each treatment was tabulated to reflect a distribution

of the number of nights that resulted in capture of each mosquito species (nights/

species/treatment). Coefficients a uk were determined, representing the probability

of a species occurring on the k -th night but none previously, given that it occurred

in k nights out of i = 1 to n = 25 nights. These coefficients were multiplied by

the probability of the species being found in only k nights out of n; the result was

summed across all remaining k. Formally,

a, k =

i-C

n—k+ 1 ,i

(n - k+ 1 )-C„/

1993

ROGERS ET AL.: CDC LIGHT TRAPS

143

and

n—k+ 1

P k = 2 a.yiS/S),

i= 1

where £,• = the number of different species appearing in i out of n samples, and

S = the number of species in n. Program source code for these computations is

available from the senior author. Computation and rationale has been discussed

in detail by Gaufin et al. (1956), who provide a worked example based on a survey

of aquatic benthos.

Results

A total of 5749 females was captured by traps during the seven nights of

collection in March. More than 36 species were represented, of which 11 were

common enough to include in Friedman tests: Anopheles mattogrossensis Lutz &

Neiva (n = 198), Aediomyia squamipennis (Lynch) ( n = 195), Culex adamesi

Sirivanakam ( n = 1497), Cx. amazonensis (Lutz) ( n = 271), Cx. corniger Theobald

( n = 93), Cx. declarator Dyar & Knab ( n = 1137), Mansonia amazonensis (Theo¬

bald) (n = 47), Ma. indubitans Dyar & Shannon ( n = 68), Coquillettidia vene-

zuelensis (Theobald) (n = 43), Uranotaenia apicalis Theobald ( n = 54), and Ur.

geometrica Theobald (n = 72).

Tests on Ma. indubitans and Cq. venezuelensis revealed no significant differences

between control traps and traps incorporating any of the light sources. Captures

of the remaining nine species were significantly (P < 0.05) higher in lighted traps,

with important differences depending on the light employed (Fig. 1).

Red, green, and yellow sticks were not equally attractive to most species. Anoph¬

eles mattogrossensis and Ur. apicalis were more attracted to yellow than to green

(P < 0.05). Red was unattractive (i.e., indistinguishable from controls) to several

species that were attracted ( P < 0.05) by both yellow and green, including: Cx.

adamesi, Cx. amazonensis, Cx. corniger, Cx. declarator, An. mattogrossensis, Ad.

squamipennis, and Ma. amazonensis. Uranotaenia apicalis and Ur. geometrica

were attracted to yellow, but not to green or red. These capture differences cannot

be ascribed to duration of light emission, inasmuch as red, green, and yellow

sticks each emitted light for 12 hours per night.

Similarly, blue and white sticks each emitted light for eight h, but Cx. adamesi

was more attracted by white than by blue.

Incandescent light was the most attractive source for Ur. apicalis and Ur. geo¬

metrica (P < 0.05). Cx. amazonensis could perceive incandescent light ( P < 0.05),

but was more attracted by chemical light sticks (P < 0.05).

Six of the species tested in March (Cx. adamesi, Cx. amazonensis, Cx. corniger,

Cx. declarator, Ad. squamipennis and Ma. amazonensis) were also present in

June, October, and January, although in much reduced numbers. The sampling

efficiency of light sticks was compared with respect to these six species. In 25

nights of sampling divided among the four months, all six species were detected

by yellow sticks in an average of 11 days, by green in 13 days, by blue in 15 days,

and by red in 25 days.

Sampling reward (the number of newly detected species) was greatest during

the first two nights of trapping with light, indicated by increased slope near the

144

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Aediomyia

squamipennis

1 3

Red

1 5.5

Control

White

Blue

Incan.

Green

38.5

Ye 11 ow

Anopheles

mattogrossensis

12 Control

22 Red

23.5 White

25.5 Green

33 Blue

37 Incan.

43 Yellow

Culex

adamesi

8.5

Control

1 9

Red

25.5

Blue

30.5

White

37.5

Yellow

37.5

Green

37.5

Incan.

Culex

amazonensis

12.5

Control

18.5

Red

Incan.

32.5

Blue

32.5

Green

33.5

Ye 11 ow

39.5

White

Culex

corniger

1 1.5

Control

Blue

Red

Yellow

White

29.5

Green

Incan.

Culex

declarator

Control

Red

White

Blue

36.5

Yellow

38.5

Green

Incan.

Mansonia

amazonensis

Uranotaenia

apicalis

Uranotaenia

geometrica

17.5

Control

19.5

Red

25.5

White

26.5

Green

33.5

Incan.

35.5

Blue

Yellow

18.5

Control

20.5

White

22.5

Green

25.5

Red

28.5

Blue

33.5

Ye 11 ow

Incan.

22.5

26.5

29.5

44.5

Control

White

Green

Red

Blue

Yellow

Incan.

Figure 1. Relative attraction of female mosquitoes to chemical and incandescent light sources,

ordered by rank sums of the Friedman test. Order is from least (top) to greatest (bottom) attraction.

Sums not subtended by the same vertical line differ at P < 0.05.

origin of P k curves (Fig. 2). For example, yellow detected four species in the first

two nights of sampling, but took nine additional nights to detect all six species.

Blue detected three species in the first two nights, and the remaining three species

13 nights later.

Discussion

A Latin square arrangement is useful in removing two extraneous sources of

variation from a desired comparison of treatments (Damon & Harvey 1987). This

ability can be particularly effective in controlling the effects of time and place in

a pilot study. Both effects are very real in mosquito surveys, due to the habitat

preferences of mosquito species, and their fluctuating population sizes over time

(Jones et al. 1991, Williams 1951). Actually, three unwanted sources of variation

(location, time, and trap effects) commonly occur in mosquito surveys, but lo¬

cation and trap effects are pooled if traps are not moved while sampling. By

leaving traps in the same collection stations during our experiments, trap variation

1993

ROGERS ET AL.: CDC LIGHT TRAPS

145

Nights

Figure 2. Average time required to detect six mosquito species at light sticks in CDC traps placed

near Iquitos, Peru. The curve for green light sticks (not shown) lies very close to yellow.

(motor speed, bag resistance to air flow, etc.) was collapsed onto the location

effects (shrubbery, wind, and so forth), and blocked.

An additional use of the Latin square is to subject data to a powerful non-

parametric test of significance used for complete block designs, the Friedman test

(Friedman 1940). This relatively old test is particularly suited to non-normal

sampling distributions such as counts of insects in traps. The recent development

of a posteriori error rates for it enhances its usefulness. Although the test is

commonly used by ecologists, it is rarely employed in insect surveys. Entomol¬

ogists have instead favored incompletely blocked designs (Belton & Pucat 1967,

Holbrook & Bobian 1989, Rowley & Jorgensen 1967, Service & Highton 1980,

Service et al. 1983, Slaff et al. 1983, Vavra et al. 1974), or transformed data and

analyses based on assumed normality and homoscedasticity (Kline et al. 1991,

Williams 1951, Williams et al. 1955). An exception is Anderson & Linhares (1989)

in which the Friedman test was used to demonstrate the attractiveness of combined

C0 2 and ultraviolet lures for Culicoides variipennis (Coquillett).

Friedman a posteriori contrasts (Fig. 1) indicate how to survey particular species

in the Iquitos study site. For example, Cx. declarator and the Uranotaenia species

should be sampled with an incandescent bulb instead of light sticks. Cx. adamesi

is attracted to white, yellow, and green sticks, and to incandescent light, but should

not be sampled with blue sticks. Cx. amazonensis should not be sampled with

incandescent bulbs. An. mattogrossensis should not be sampled with green or

white sticks. Red should not be used for any of the 11 species tested.

The strong performance of incandescent light in most tests may owe to the fact

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THE PAN-PACIFIC ENTOMOLOGIST

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that incandescent bulbs emit light longer than light sticks. Long duration of light

emission is an advantageous quality that extends specimen collection from evening

well into the following morning, thereby increasing trap exposure to crepuscular

species. Nevertheless, the decision to use incandescent light depends on which

species are of interest. For example, incandescent light lasting 15.5 h was definitely

less productive in collecting Cx. amazonensis than were white sticks that last

eight h (Fig. 1).

Because the Friedman test checks the equality of treatments, it is sensitive to

the effects of mosquito repellency as well as attraction (positive and negative

phototaxis). However, a control can be used to distinguish the two effects. Thus,

there was no evidence of mosquito repellency by red or other treatments in the

March survey, because the experimental control was never significantly (P < 0.05)

more productive than any treatment in a posteriori comparisons. For the same

reason, we cannot conclude that Ma. indubitans and Cq. venezuelensis were either

repelled or attracted by light of any kind.

The generally poor performance of red sticks is noteworthy, as is the failure to

capture Ma. indubitans and Cq. venezuelensis at light. Both observations are

important from the practical standpoint of sampling this local fauna. However,

we stress that these results should not be generalized to faunas composed of other

species, nor to surveys of the same species in other localities. Pilot studies should

always be conducted in the locale of interest, before conclusions are drawn.

Sampling efficiency is broadly defined as the cost necessary to obtain an estimate

of a desired precision (Freese 1962). The cost can be stated in various currencies

to serve specific purposes (Castleberry et al. 1989, Wilkinson & Gregson 1985,

Zimmerman & Garris 1985). For mosquito surveys, which incur costs related to

the nightly labor of servicing traps, it is intuitively meaningful to express efficiency

as the number of trap nights needed to detect a given number of species. Viewed

in these terms, the most efficient attractant is that which captures more species

in less time than other attractants. It represents the best compromise for sampling

a local fauna.

We, therefore, compared the average rapidity with which certain important

species were recovered in traps, by a method that translated mosquito capture

rates into time cost. It estimated the proportion of the species captured in a large

number of nights that would have been detected, on the average, in a smaller

number of nights. Under conditions prevailing in the study site during March,

June, October, and January, yellow sticks were more efficient than red, blue or

green in surveying a fauna composed of Cx. corniger, Cx. adamesi, Cx. declarator,

Cx. amazonensis, Ad. squamipennis, and Ma. amazonensis. The amount of survey

time saved by use of yellow to detect all six species ranged from two days (com¬

pared to green) to 14 days (compared to red).

Some practical generalizations deserve emphasis in conclusion. First, the ad¬

vantage in choosing an efficient mosquito attractant is realized in a few initial

evenings of use. Most of the species that can be detected are caught rather quickly,

in about two nights. Second, chemical light sticks can be more productive than

incandescent bulbs in collecting certain species. Finally, the amount of time needed

to detect a given number of mosquito species depends upon which light stick is

employed.

1993

ROGERS ET AL.: CDC LIGHT TRAPS

147

Acknowledgment

The authors are indebted to Bruce Harrison, Richard Wilkerson and Edward

Peyton for identification of the mosquito species captured in this survey. We

likewise thank Alfredo Barboza, Adriana Silva and Faustino Carbajal, for prep¬

aration of the illustrations. Early versions of the manuscript were improved by

comments from Joel Escamilla, Donald Roberts and Stephen Wignall. Field as¬

sistance was provided by Ernesto Colan, Roberto Fernandez and Javier Macedo.

We credit Marvin Lawson and Jack Peterson for useful discussions. Preparation

of the typescript was supervised by Lucy Rubio.

Literature Cited

Anderson, J. R. & A. X. Linhares. 1989. Comparison of several different trapping methods for

Culicoides variipennis (Diptera: Ceratopogonidae). J. Am. Mosq. Control Assoc., 5: 325-334.

Belton, P. & A. Pucat. 1967. A comparison of different lights in traps for Culicoides (Diptera:

Ceratopogonidae). Can. Entomol., 99: 267-272.

Castleberry, D. T., J. J. Cech Jr. & A. B. Kristensen. 1989. Evaluation of the effect of varying

mosquito emergence on the efficiency of emergence traps over enclosed environments. J. Am.

Mosq. Control Assoc., 5: 104-105.

Conover, W. J. 1980. Practical nonparametric statistics (2nd ed.). John Wiley & Sons, New York,

New York.

Damon, R. A. & W. R. Harvey. 1987. Experimental design, ANOVA, and regression. Harper &

Row, New York.

Freese, F. 1962. Elementary forest sampling. U.S. Dep. Agric. Handb.

Friedman, M. 1940. A comparison of alternative tests of significance for the problem of m rankings.

Ann. Math. Statist., 11: 86-92.

Gaufin, A. R., E. K. Harris & H. J. Walter. 1956. A statistical evaluation of stream bottom sampling

data obtained from three standard samplers. Ecology, 37: 643-648.

Holbrook, F. R. & R. J. Bobian. 1989. Comparisons of light traps for monitoring adult Culicoides

variipennis (Diptera: Ceratopogonidae). J. Am. Mosq. Control Assoc., 5: 558-562.

Huffaker, C. B. & R. C. Back. 1943. A study of methods of sampling mosquito populations. J. Econ.

Entomol., 36: 561-569.

Jones, R. E., P. Barker-Hudson & B. H. Kay. 1991. Comparison of dry ice baited light traps with

human bait collections for surveillance of mosquitoes in Northern Queensland, Australia. J.

Am. Mosq. Control Assoc., 7: 387-394.

Kline, D. L., D. A. Dame & M. V. Meisch. 1991. Evaluation of l-octen-3-ol and carbon dioxide as

attractants for mosquitoes associated with irrigated rice fields in Arkansas. J. Am. Mosq. Control

Assoc., 7: 165-169.

Rowley, W. A. & N. M. Jorgensen. 1967. Relative effectiveness of three types of light traps in

collecting adult Culicoides. J. Econ. Entomol., 60: 1478-1479.

Service, M. W. & R. B. Highton. 1980. A chemical light trap for mosquitoes and other biting insects.

J. Med. Entomol., 17: 183-185.

Service, M. W., S. Sulaiman & R. Esena. 1983. A chemical aquatic light trap for mosquito larvae

(Diptera: Culicidae). J. Med. Entomol., 20: 659-663.

Slaff, M., W. J. Crans & L. J. McCuiston. 1983. A comparison of three mosquito sampling techniques

in northwestern New Jersey. Mosq. News, 43: 287-290.

Vavra, R. W., R. R. Carestia, R. L. Frommer & E. J. Gerberg. 1974. Field evaluation of alternative

light sources as mosquito attractants in the Panama Canal Zone. Mosq. News, 34: 382-384.

Wilkinson, P. R. & J. D. Gregson. 1985. Comparisons of sampling methods for recording the numbers

of Rocky Mountain wood ticks ( Dermacentor andersoni ) on cattle and range vegetation during

control experiments. Acarologia, 26: 131-139.

Williams, C. B. 1951. Comparing the efficiency of insect traps. Bull. Entomol. Res., 42: 513-517.

Williams, C. B., R. A. French & M. M. Hosni. 1955. A second experiment on testing the relative

efficiency of insect traps. Bull. Entomol. Res., 46: 193-204.

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Zimmerman, R. H. & G. I. Garris. 1985. Sampling efficiency of three dragging techniques for the

collection of nonparasitic Boophilus microplus (Acari: Ixodidae) larvae in Puerto Rico. J. Econ.

Entomol., 78: 627-631.

Received 3 February 1992; accepted 18 March 1993.

PAN-PACIFIC ENTOMOLOGIST

69(2): 149-154, (1993)

RECORDS OF CERAMBYCIDS FROM THE MARIANA

ISLANDS, MICRONESIA, WITH DESCRIPTION OF A

NEW SPECIES OF THE GENUS SYBRA

(COLEOPTERA: CERAMBYCIDAE: LAMIINAE)

Ryutaro Iwata

Department of Forestry, College of Agriculture and Veterinary Medicine,

Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252, Japan

Abstract .—Eight cerambycid species (Lamiinae) collected at four islands (Saipan, Tinian, Rota

and Guam) of the Mariana Islands in December, 1989-1991, are recorded. Sybra guamensis

NEW SPECIES is described from Guam, and Sciades ( Micronesiella ) boharti (Gressitt) is newly

recorded from Saipan and Rota.

Key Words.— Insecta, Coleoptera, Cerambycidae, Lamiinae, Micronesia, Mariana Islands

Although many reports have been published on the cerambycid fauna of the

Bonin Islands, Japan, including biogeographical revisions by Fujita (1976) and

Makihara (1987), very few records have been published from the Mariana Islands,

which are situated directly south of the Bonin Islands, since Gressitt’s (1956)

revision of the cerambycid fauna of Micronesia. The fauna of the Mariana Islands

is of great interest to Japanese biogeographers because the two island groups form

a chain.

I had opportunities to visit and collect cerambycid beetles on four of the Mariana

Islands: Guam and Rota, in 1989 December, Saipan and Tinian, in 1990 Decem¬

ber, and again Guam in 1991 December.

This paper records the data obtained, as well as the description of a new species

belonging to the genus Sybra and a note on Sciades ( Micronesiella ) spp. All

specimens were collected by me, and are included in my collection in Nihon

University, except for the holotype and one paratype of the new species, which

are deposited in the National Science Museum (Natural History), Tokyo, Japan.

The generic and subgeneric status of Sciades spp. follows the most recent treatment

by Breuning (1977).

Prosoplus bankii (Fabr.)

Japanese Name. — Murayama-munekobu-sabi-kamikiri.

Records.—GUAM. Turnon Beach, 23 Dec 1989, 1 female; same locality, 22 Dec 1991, 2 males, 3

females. NORTHERN MARIANA ISLANDS. TINIAN: Tinian Shrine, 22 Dec 1990, 1 male. ROTA:

Tatuga Beach, 21 Dec 1989, 4 males, 2 females.

Sybra (s. str.) alternans (Wiedemann)

Figs. 1, 2, 5, 6, 7

Japanese Name. — Kuro-chibi-kamikiri.

Records.— GUAM. Talofofo Falls, 22 Dec 1989, 1 female; Turnon Beach, 23 Dec 1989, 5 males,

2 females; Fujita Guam Tumon Beach Hotel, Turnon Beach, 23 Dec 1989, 1 female; Turnon Beach,

21 Dec 1991, 2 males, 2 females; same locality, 22 Dec 1991, 15 males, 13 females (Figs. 1, 2).

150

THE PAN-PACIFIC ENTOMOLOGIST Vol. 69(2)

Figures 1-2. Sybra (s. str.) alternans (Wiedemann) (scale: 10 mm). Figure 1. Male. Figure 2.

Female. Figures 3-4. Sybra (s. str.) guamensis Iwata (scale: 10 mm). Figure 3. Male (holotype). Figure

4. Female (paratype).

1993

IWATA: CERAMBYCIDAE OF THE MARIANA ISLANDS

151

Figures 5-7. Male genital organs of Sybra alternans (scale: approximately 1 mm). Figure 5. Median

lobe in lateral view. Figure 6. Median lobe in dorsal view. Figure 7. Lateral lobes.

NORTHERN MARIANA ISLANDS. SAIPAN: Navy Hill near Garapan, 20 Dec 1990, 1 male;

Lourdes Shrine, 21 Dec 1990, 1 male, 3 females.

Sybra (s. str.) guamensis Iwata, NEW SPECIES

Figs. 3, 4, 8, 9, 10

Types. — Holotype: male (Fig. 3), deposited in National Science Museum (Nat¬

ural History), Tokyo, Japan, data: GUAM. Turnon Beach, 22 Dec 1991, R. Iwata.

Paratypes: 1 female, same locality as holotype, 23 Dec 1989; 2 males, 2 females

(Fig. 4), same data as holotype.

Description. —Male. Length: 10.6-10.8 mm. Color: head dark brown, densely clothed with fine long

red-brown hairs; pronotum dark brown, median area very sparsely clothed with red-brown hairs,

sublateral areas with white pubescence, other parts with dense fine red-brown pubescence; scutellum

posteriorly clothed with bright red-brown hairs; elytra dark brown, with fine red-brown and white

pubescence arranged in alternate longitudinal rows of variable width; sterna pitchy brown, very finely

and densely clothed with tawny pubescence; antennae brown to dark brown, with very fine tawny

pubescence, apices of segments 4-11 much darker and lacking pubescence; legs brown, with dense

long red-brown and white hairs. Head: almost as broad as anterior edge of pronotum; frons not

punctate, broader than long; vertex punctate; genae approximately 0.7-0.8 x as deep as inferior eye-

lobes. Antennae: approximately 1.3-1.4 x as long as body, segments 2-8 inferiorly with suberect setae;

scape subfusiform; third segment slightly but distinctly shorter than fourth. Prothorax: as broad as or

slightly broader than long, distinctly punctate, convex at center. Elytra: approximately 2.5 x as long

as wide, approximately 2.2 x as long as head plus prothorax, bearing rather regularly arranged punctures

in 9 rows; lateral margins subparallel along anterior two-thirds; apices rotundate-truncate. Scutellum

linguiform, broader than long. Legs: robust; femora markedly swollen; mid- and hind-tibiae apically

with row of strong setae. Genitalia: with a simple median lobe (Figs. 8, 9), lateral lobes stout, parallel¬

sided medially (Fig. 10).

Female. Length: 8.8-12.0 mm. Antennae approximately 1.1 x as long as body. Pronotum slightly

broader than long. Elytra with denser pubescence and alternate rows more distinct.

Diagnosis. — This new species is closely related to, and resembles, S. (s. str.)

alternans, but is distinguishable from it in having: (1) thicker antennae, (2) a non-

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Vol. 69(2)

Figures 8-10. Male genital organs of Sybra guamensis (scale: approximately 1 mm). Figure 8.

Median lobe in lateral view. Figure 9. Median lobe in dorsal view. Figure 10. Lateral lobes.

punctate frons, (3) elytra lacking white elongate patches and having blunter apices,

and (4) the male genital organ with a blunter apex of median lobe (Figs. 5, 6, 8,

9), as well as with stouter lateral lobes rather parallel-sided medially (Figs. 7, 10).

This species seems also to resemble another species endemic to Guam, Sybra

(s. str.) schurmanni Breuning, but is distinguishable from it, according to its

description by Breuning (1983), in having: (1) longer antennae, (2) antenna seg¬

ment 3 shorter than 4, (3) elytra lacking light-yellow patches, and (4) the apical

halves of tibiae lacking dark-brown hairs.

New Japanese Name. — Guamu-chibi-kamikiri.

Distribution.—G uam (USA).

Biological Remarks. — All of the types were captured in a tree grove and bush

Figures 11-12. Sciades (Micronesiella ) spp. (scale: 5 mm). Figure 11. Sciades (M.) marianus (Gres-

sitt), female. Figure 12. Sciades (M.) boharti (Gressitt), female.

1993

I WAT A: CERAMBY CIDAE OF THE MARIANA ISLANDS

153

that are very near a swimming beach and resort hotels, and it is possible that it

is an introduced species. They were captured, together with S. alternans, by beating

dead branches of broad-leaved trees with dead leaves still attached. It appears

that the capture location will be destroyed in the near future, due to the construc¬

tion of new hotels.

Etymology.— An adjective (female, nominative) from the name of the type

locality, Guam.

Material Examined.—See types.

Ropica squamulosa Breuning

New Japanese Name. — Uroko-chibi-sabi-kamikiri.

Records. — GUAM. Tumon Beach, 21 Dec 1991, 1 male; same locality, 22 Dec 1991, 1 male.

NORTHERN MARIANA ISLANDS. SAIPAN: Navy Hill near Garapan, 20 Dec 1990, 1 male, 6

females; Lourdes Shrine, 21 Dec 1990, 2 males, 5 females. TINIAN: Carolinas Heights, 22 Dec 1990,

1 male, 1 female. ROTA: Tatuga Beach, 21 Dec 1989, 1 male, 1 female; Teteto Beach, 21 Dec 1989,

1 female.

Pterolophia (s. str.) bigibbera (Newman)

Japanese Name.— Sujidaka-sabi-kamikiri.

Records.— GUAM. Tumon Beach, 23 Dec 1989, 4 males, 3 females; same locality, 22 Dec 1991,

2 males, 1 female. NORTHERN MARIANA ISLANDS. SAIPAN: Navy Hill near Garapan, 20 Dec

1990, 3 males; Lourdes Shrine, 21 Dec 1990, 1 male. TINIAN: Mt. Lasso, 22 Dec 1990, 1 female;

Carolinas Heights, 22 Dec 1990, 3 males, 1 female; Tinian Shrine, 22 Dec 1990, 1 female. ROTA:

Tatuga Beach, 21 Dec 1989, 2 males, 1 female; Teteto Beach, 21 Dec 1989, 1 male.

SCIADES ( MlCRONESIELLA ) MARIANUS (GRESSITT)

Fig. 11

New Japanese Name. — Mariana-keshi-kamikiri.

Records.—GUAM.. Talofofo, 22 Dec 1989, 1 male, 1 female. NORTHERN MARIANA ISLANDS.

SAIPAN: Navy Hill near Garapan, 20 Dec 1990, 3 males, 2 females; Lourdes Shrine, 21 Dec 1990,

1 female. ROTA: Tatuga Beach, 21 Dec 1989, 6 males, 1 female.

SCIADES (. MlCRONESIELLA ) BOHARTI (GRESSITT)

Fig. 12

New Japanese Name. — Bohato-keshi-kamikiri.

Remarks.— These are new records from both of the islands. This species, as

originally described from Agrihan Island in the Marianas, can be distinguished

from S. (M.) marianus by its shorter antennae and a wider pronotum (Gressitt

1956). However, its status in relation to S. marianus is still tentative and it may

prove to be a synonym of that species, which is quite variable.

Records. — NORTHERN MARIANA ISLANDS. SAIPAN: Navy Hill near Garapan, 20 Dec 1990,

2 females. ROTA: Teteto Beach, 21 Dec 1989, 1 female.

SCIADES ( MlAENIA ) MERIDIANUS (K. OHBAYASHl)

New Japanese Name. — Minami-futatsume-keshi-kamikiri.

Records. — NORTHERN MARIANA ISLANDS. SAIPAN: Lourdes Shrine, 21 Dec 1990, 1 male

(without distinct elytral markings).

154

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Vol. 69(2)

Literature Cited

Breuning, S. 1977. Revision de la tribu des Acanthocinini de la region asiato-australienne (Coleoptera:

Cerambycidae). Mitt. Zool. Mus. Berlin, 53: 199-276, Taf.I-IV.

Breuning, S. 1983. Nouvelles formes de Lamiinae de l’Ouest du Pacifique, recoltes par le Dr. Peter

Schumann. Bull. Soc. Entomol. Mulhouse, 1983(Avr.-Juin): 31.

Fujita, H. 1976. [Longicom-beetle fauna of the Bonin Islands.] Gekkan-Mushi (Monthly J. Entomol.),

Tokyo, 68: 27-31 (in Japanese).

Gressitt, J. L. 1956. Insects of Micronesia, Coleoptera: Cerambycidae. Ins. Micronesia, Bern. P.

Bishop Mus., Honolulu, 17: 61-183.

Makihara, H. 1987. [Cerambycid fauna of Bonin Islands.] Ogasawara Kenkyu Nenpo (Annu. Rep.

Bonin Isis. Res.), Tokyo, 11: 17-31 (in Japanese).

Received 19 February 1992; accepted 1 July 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 155-170, (1993)

BIOLOGICAL STUDIES OF

HEMICOELUS GIBB1COLLIS (LECONTE)

(COLEOPTERA: ANOBIIDAE), A SERIOUS STRUCTURAL

PEST ALONG THE PACIFIC COAST:

ADULT AND EGG STAGES

Daniel A. Suomi and Roger D. Akre

Department of Entomology, Washington State University,

Pullman, Washington 99164

Abstract.— The anobiid beetle, Hemicoelus gibbicollis (LeConte), is among the most serious

structure-infesting insect pests along coastal areas of western North America. Adult beetles are

difficult to find due to their small size, cryptic coloration, and sedentary behavior. They readily

oviposit in crevices of building timbers that eventually may be damaged sufficiently to require

replacement. Females can lay in excess of 100 eggs and egg hatch ranges between 85 and 89%.

Pheromones play a key role in mate location. These beetles are primarily found in damp crawl

spaces and unheated outbuildings.

Key Words. — Insecta, Hemicoelus gibbicollis, structure-infesting, adult, egg, pheromone

Structural damage caused by anobiid beetles in the northwestern United States

has only recently come to the attention of concerned individuals. Prior to 1970,

structural pest inspections were seldom conducted before home sales (T. Whit¬

worth, personal communication), so many infestations went undetected. During

the 1980s home prices dramatically increased and inspections became common.

Additionally, energy audits conducted by public utilities prior to home insulation

programs revealed many serious infestations. As a result of these inspections the

extent of beetle damage became much more apparent.

Hemicoelus gibbicollis (LeConte) is the most widespread and damaging anobiid

in coastal areas of Washington, Oregon, California, and British Columbia (Suomi

1992). Despite the damage caused by this insect, its biology has remained unre¬

corded (Fumiss & Carolin 1977). A project was begun in 1987 to document the

biology and management options of the most damaging anobiids in Washington

and adjacent areas. This, and a subsequent paper (Suomi & Akre in press), will

describe the life stages, biology, and behavior of H. gibbicollis.

Anobiids are difficult to study, and the biologies of only a few species have

been documented. The furniture beetle, Anobium punctatum (De Geer), is prob¬

ably the best known wood-infesting anobiid. This insect is the most serious wood-

destroying pest throughout England and much of northern Europe, far surpassing

termites or any other group of insects (Hickin 1975). Studies conducted by various

researchers (Becker 1940; Spiller 1948; Bletchly 1952; Hickin 1953, 1960, 1981;

Fisher 1958; Berry 1976) reported most of our knowledge regarding this species.

The deathwatch beetle, Xestobium rufovillosum (De Geer), caused damage to

several wooden landmarks in England and the United States that led Fisher (1937,

1938, 1940, 1941) to document its habits. Moore (1968, 1970), Williams (1977,

1983), and Williams & Mauldin (1974, 1981) studied another structure-infesting

anobiid, Euvrilletta peltata (Harris), and reported on life cycle, wood species

156

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

infested, and management options. Little information on other wood-infesting

anobiids exists because of; 1) long life cycles, often in excess of 5 years, 2) difficulty

in rearing, and 3) small size and sedentary behavior of the adults.

Materials and Methods

Wood Collection and Storage. —Subflooring and support timbers, primarily

Douglas-fir, Pseudotsuga menziesii (Mirbel), infested with H. gibbicollis larvae

were collected from western Washington and Oregon homes and outbuildings

during June, July, and August, 1987 to 1991. This wood was transported to the

laboratory at Washington State University in sealed containers to maintain mois¬

ture content at the higher levels found in coastal areas. A concrete blockhouse (4

m by 1 m by 1 m and covered with 6 mil black polyethylene) was constructed in

a shaded location to retain infested timbers until they could be cut into smaller

pieces, approximately 30 cm long. These pieces were kept in covered, darkened

boxes measuring 38 cm by 28 cm by 15 cm with 1 cm plaster of Paris/charcoal

as a substrate to maintain wood moisture between 14 and 17%. Ventilation was

provided through two screen-covered holes (35 mm diameter) in the top cover.

Wood moisture readings were taken with a Delmhorst Model RC-1C Moisture

Meter (Delmhorst Instrument Company, Boonton, New Jersey). An environ¬

mental growth chamber was used to maintain conditions at 65 ± 3% RH and 18

± 1° C. These conditions are commonly found in crawl spaces under buildings

in western Washington. Daily observations were made, and upon emergence adult

beetles were collected, measured, sexed, and individually stored in gauze-covered

glass vials until tested.

Oviposition Chambers.— Bottoms of clear, polystyrene insect diet cups (4 cm

tall by 4 cm diameter) were removed and replaced with plastic mesh glued in

place. One layer of muslin cloth was attached to a 9 cm by 9 cm by 2 cm wood

block top surface to permit oviposition. A male and female beetle were released

in each cup which was then inverted and positioned in the center of the block.

Test blocks were kept in separate enclosures, and egg counts were made after 30

days. Relative humidity was recorded with a thermohygrometer (Model 8564,

Hanna Instrument Company, Chicago, Illinois) and maintained at two levels with

saturated salt solutions (Winston & Bates 1960); 75 ± 1% with sodium chloride

and 85 ± 1% with potassium chloride (Sigma Chemical Company, St. Louis,

Missouri). Relative humidities below 50% and at 65 ± 3% were maintained in

laboratory incubators.

Pheromone Tests. — A modified 9 cm plastic petri dish served as the test arena

(Suomi et al. 1986). Ovipositors were dissected from ten newly-emerged H. gib¬

bicollis, ground in 3 ml methylene chloride, and the extract filtered. Filter paper,

0.5 cm 2 , was immersed in this solution and allowed to air dry. Control filter paper

squares were immersed in methylene chloride alone. In the arena a filter paper

square was placed at each 90 degree interval with test and control squares alter¬

nating, for a total of 4 squares. Stegobiol (Fuji Flavor Co., Ltd., Tokyo, Japan),

a commercially available attractant for the drugstore beetle, Stegobium paniceum

(L.), was tested in a similar manner. Pheromone packets were placed at opposing

locations within the arena; empty packets served as controls. Three male H.

gibbicollis were released in the arena center and their movements monitored under

red-filtered light. Five replicates were conducted for each material.

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SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

157

Figure 1. Lateral view, male H. gibbicollis (x 30).

Scanning Electron Microscopy. — The external morphology of male and female

H. gibbicollis was examined with a scanning electron microscope (SEM; Hitachi

S570) at 20 kV. Dried specimens were placed on cardboard points, then mounted

on stubs and coated with 30 nm of gold using a Technics Hummer Sputter Coater

V. Antennae were removed from 11 beetles (6 males and 5 females), mounted,

and individually gold-coated for increased clarity.

Results and Discussion

Adults. —Hemicoelus gibbicollis adults are small beetles. Males range in size

from 2.5-5.1 mm, (n = 165, x = 3.4 mm), and females range from 3.5-6.0 mm

(n = 95, x = 4.9 mm). They are light to chocolate brown, occasionally red or dark

brown. The eyes of the male tend to be larger than those of the female (Figs. 1,

2). A more reliable character for differentiating between sexes is a semicircular

depression in the last abdominal sternum, clearly present in males (Figs. 3, 4).

Hemicoelus gibbicollis can be separated from most anobiid species in the Pacific

Northwest by a pointed, thoracic dorsum (Figs. 1, 2). LeConte’s (1859) original

description is from a specimen collected at Point Reyes, near San Francisco,

California.

Emergence. — Adults emerge any time during the day or night. Both sexes chew

a circular exit hole approximately 1.5 mm in diameter. Small amounts of frass

are evident during this procedure. Eight adult emergences were witnessed, the

shortest was 25 min, the longest 18 h. Upon emergence both males and females

moved rapidly on the wood surface. If overturned, the beetles used their wings

to right themselves, but despite being probed with objects, were not driven to

flight. Several authors (Linsley 1943, Mampe 1982) reported that anobiid adults

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Figure 2. Lateral view, female H. gibbicollis (x45).

Figure 3. Terminal abdominal sternum, male H. gibbicollis (x 150).

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SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

159

Figure 4. Terminal abdominal sternum, female H. gibbicollis (x 60).

were attracted to lighted windows and when found in spider webs, one could

assess the amount of beetle activity in the structure. During this research only a

single male was observed flying toward a florescent light in the laboratory. Keen

(1895) stated that H. gibbicollis could be captured in flight, but that it was a rare

occurrence.

Kelsey et al. (1945) noted a “swarming” phenomenon where 167 male and 3

female A. punctatum were found at the same site on a timber. We observed similar

behavior on three separate occasions but with smaller numbers of insects (< 20,

both sexes). Following this event the wood from which these insects emerged

produced very few adult beetles the following year. Pheromones may mediate

this coordinated emergence.

In general, anobiid beetles are rarely collected in good numbers (White 1969).

Although a building can be seriously infested, H. gibbicollis adults are difficult to

locate. Both males and females remained motionless on the surface unless engaged

in reproductive behavior. Females had a greater tendency to withdraw into emer¬

gence holes. When disturbed, males and females feigned death by drawing the

appendages close to the body and remained motionless for several minutes. In

the laboratory, beetle activity increased between 18:00 and 03:00 h, but adults

were seen copulating or ovipositing at various times during the day. After these

activities ceased, both males and females returned to a sheltered location, usually

an old emergence hole, where they eventually died. Seven male and eight female

beetles were closely observed to document longevity (Table 1).

Each year more males than females were collected during laboratory emergences

(Table 2). Searching behavior by males may result in increased exposure and

greater numbers recorded. Males attempted to copulate immediately upon emer-

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Vol. 69(2)

Table 1. Longevity of male and female H. gibbicollis adults.

Female No.

No. days surviving

Male No.

No. days surviving

X = 24.13 ± 2.59 a

X = 20.71 ± 3.55 a

a Means ± SEM followed by the same letter do not differ significantly (P = 0.05) based on /-tests

(SAS Institute 1985).

gence, but female beetles required 24-36 h before successful copulation occurred.

Upon emergence, females located a crack or depression where they remained prior

to mating. Generally, males did not attempt to mate with females found in these

locations.

Chemical Communication. — Female H. gibbicollis exhibited a calling behavior

similar to that observed in other anobiids (Cymorek 1960). The abdomen was

raised 45 degrees to the substrate, and the ovipositor tip then everted. A female

remained in this position for approximately 15 sec, then returned to a horizontal

position for about 30 sec. This behavior was repeated six to eight times, or until

a male appeared. A male within 20 cm of the female immediately responded and

approached, antennated her head area for 3-4 sec, circled, and mounted from

behind. The male then rotated 180 degrees and both beetles remained motionless.

Nine observed matings took place under either fluorescent or red-filtered light.

Duration of the copulatory period averaged 65.4 min (range = 44-133 min).

In petri dish arenas (n = 5 replicates), male H. gibbicollis were immediately

attracted to filter paper treated with female ovipositor extract. Males antennated

the paper 3-4 sec, then remained motionless adjacent to the paper. After 10-15

min, the males moved to the periphery of the arena and ceased movement. On

one occasion a male that contacted treated filter paper was pursued by another

in an attempt at copulation. This continued for several minutes until the pursuing

male lost interest. Beetles did not respond to filter paper controls.

Table 2. Number of male and female H. gibbicollis adults emerged from samples during 1987—

1991, eastern Washington.

Year

No. males

No. females

1987

1988

1989

132

1990

186

108

1991

x — 106.40 ± 23.88 a

X = 79.20 ± 9.62 a

a Means ± SEM followed by the same letter do not differ significantly (P = 0.05) based on /-tests

(SAS Institute 1985).

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SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

161

Figure 5. Hemicoelus gibbicollis antennal segments 5 and 6 (x 1000).

Observations were made of six male and five female H. gibbicollis adult antennae

to determine if sensory structures were present for sex pheromone reception.

Unlike most species that use attractant pheromones (Payne 1974), there is no

marked sexual dimorphism of antennal size or shape in this species. All antennal

segments of males and females (Fig. 5) are covered with hairs which may be

sensory in nature, but these are not thought to be pheromone receptors (Chapman

1982). In species using chemicals as sex attractants, one type of sensory device,

the sensilla trichodea, is responsible for sex pheromone perception. These sense

receptors were found in greater numbers on male antennae. A presumed olfactory

sensillum (Figs. 6, 7) is present which is similar to those seen in the bedbug,

Cimex lectularius L. (Levinson et al. 1974). Male beetles had, on average, twice

as many of these structures on antennal segments 9-11 than did females. Numbers

of sensillae were relatively low (approximately 12 in males) which may indicate

that large amounts of pheromone are released by the female.

In studies conducted on insects relying on chemoreceptors to detect sex pher¬

omones, openings or pores in the integument were often found in large numbers

(Steinbrecht 1987). These pores are thought to allow passage of odor molecules

while preventing water loss (Fig. 8). Male H. gibbicollis beetles had approximately

50% more of these pores on antennal segments 9-11 than were present on female

antennae.

A sex pheromone, stegobiol, has been isolated from S. paniceum and is available

for use in pheromone traps (Fuji Traps, Tama Trading Co., Ltd., Tokyo, Japan).

This compound was discovered (White & Birch 1987) to be structurally identical

to the mating pheromone produced by female A. punctatum. In laboratory arenas

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Vol. 69(2)

Figure 6. Male H. gibbicollis antennal segment 10; note presumed sensilla (x 1000).

Figure 7. Presumed olfactory sensillum of H. gibbicollis (x 7000).

1993

SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

163

Figure 8. Presumed integumentary pheromone receptor pore; H. gibbicollis male antennal segment

11 (x 4000).

and field trials stegobiol was ineffective as an attractant for H. gibbicollis males.

The authors stated that stegobiol isomerizes over time and becomes inhibitory

to S. paniceum. Within laboratory arenas, male H. gibbicollis rapidly moved away

from the material when placed near it, possibly due to isomerization of the com¬

pound.

Oviposition. —After mating, females located sheltered sites, such as cracks in

wood or old exit holes, and remained motionless for 18-36 h. On four separate

occasions males mated with three different females. Females were, on three oc¬

casions, observed to mate after they had initially oviposited. Few eggs were pro¬

duced after these second matings (range = 3-8, x = 6). Females laid eggs singly

or in clusters of >100 in cracks or the end grain of the wood. Rarely were eggs

laid in old exit holes. Kelsey (1946) and Bletchly (1952) used muslin to encourage

oviposition of A. punctatum with good results. Thus, on smooth wood surfaces

in laboratory tests, muslin cloth was used to stimulate oviposition. In 1990 and

again in 1991,14 females were permitted to oviposit on this surface. Eggs produced

per female ranged from 0 to 202, x = 33.9 per female. These numbers are similar

to those reported by Spiller (1964) for A. punctatum (range = 0-123, x = 54.8

per female). In several instances no eggs were produced which may have resulted

from female beetles ovipositing prior to capture (Bletchly 1952). Other oviposition

studies conducted in 1989 and 1990 resulted in a smaller number of eggs produced

per female (Table 3).

A female extruded her ovipositor for 3-4 sec before an egg became visible. Five

to 10 sec elapsed for each egg to be laid. While moving through the oviduct

anobiid eggs are coated with symbiotic yeasts which supply the larvae with nu-

164

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Vol. 69(2)

Figure 9. Adult H. gibbicollis emergence; e. Washington, 1987.

■d

trients and amino acids (Jurzitza 1979). An adhesive material is produced by the

colleterial glands of the female which adheres eggs to the substrate.

Eggs.—Hemicoelus gibbicollis eggs are approximately 0.5 mm long, creamy

white, and tapered. A micropyle is evident at one end of the egg. Eggs are typically

laid in cracks and crevices and are often distorted when forced into these restricted

sites. Larval morphology did not become apparent until a few days before eclosion.

Between 85 and 89% of eggs hatch under laboratory conditions which simulated

the crawl space environment found in western Washington homes (Table 3). These

conditions support a wood moisture regime between 13 and 19% that creates an

environment conducive to anobiid larval development. Eggs required between 2-

4 weeks to produce first instars (Suomi 1992). No eggs hatched when the RH was

<50% (uncommon in western Washington), and fungal development prevented

larval emergence if the RH exceeded 85%. Eggs developed normally between these

Table 3. Eggs produced, 3 percent hatch, and number of days to emergence; field collected H.

gibbicollis.

Year

Total no.

females

Mean no. eggs/

female (range) b

Mean no. days

to hatch (range)

% hatch

1989

18.7 ± 3.9 a

22.1 ± 0.5 a

88.6

(3-32)

(11-33)

1990

17.4 ± 6.5 a

16.9 ± 0.3 b

84.9

(1-50)

(10-31)

3 Adults and eggs were maintained in observation boxes at 65 ± 3% RH and 18 ± 1° C.

b Means ± SEM followed by the same letter do not differ significantly (P = 0.05) based on (-tests

(SAS Institute 1985).

No. Emerged s= No. Emerged

1993

SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

165

Jan Mar May Jul Aug Sep Nov

Adult H. gibbicollis emergence; e. Washington, 1988.

Jan Mar May Jul Aug Sep Nov

Figure 11. Adult H. gibbicollis emergence; e. Washington, 1989.

No. Emerged pj No. Emerged

166 THE PAN-PACIFIC ENTOMOLOGIST Vol. 69(2)

Adult H. gibbicollis emergence; e. Washington, 1990.

Jan Mar May Jul Aug

Figure 13. Adult H. gibbicollis emergence; e. Washington, 1991.

Sep

Nov

1993

SUOMI & AKRE: H. GIBBICOLLIS ADULTS AND EGGS

167

British

■SpLUHFiiA

w *SHm

c ANADA

gton

°R£gon

Ca LIFq Rnia

Figure 14. Distribution of the structure-infesting anobiid, H. gibbicollis, western United States.

extremes. The moisture content of recently milled, air-dried lumber found in

lumberyards is probably too high for most H. gibbicollis eggs to survive.

Adult Activity Period. — Adult beetles are active primarily during summer months

in the Pacific Northwest. Laboratory emergence records during 1987-1991 showed

that H. gibbicollis began emerging in early June and continued until late August.

In warmer parts of the range (southern California), emergence may start earlier

and continue later in the year. Records acquired from museums and collections

along the Pacific Coast (Suomi 1992) showed that most adults were captured

during these months. The earliest laboratory collections were on 9 Apr and the

Table 4. Temperature extremes (°C) in emergence containers, eastern Washington.

Year

Maximum

Minimum

1987

35.0

-19.0

1988

34.5

-20.5

1989

39.5

-27.0

1990

36.0

-18.0

168

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(2)

latest on 18 Dec (Suomi 1992: appendix 4). These emergences were unusual and

probably represent a response to laboratory conditions. The earliest field collec¬

tions of H. gibbicollis were made in Marin County, California on 1 Apr and the

latest from 22 Oct in Lincoln County, Oregon. Label data did not always state

whether the beetles were alive or dead when collected. Still, only 17 of 183 field

collections were made before June or after August (Suomi 1992: appendix 2).

Adult beetle emergence in the laboratory during 1987-1991 closely followed this

trend, as 869 of 928 collections were made during June, July, and August (Figs.

9-13).

Hemicoelus gibbicollis occurs, for the most part, along the Pacific Coast of

western North America where milder climatic conditions prevail (Fig. 14). Higher

relative humidity, resulting in greater wood moisture, creates conditions condu¬

cive to their survival (Suomi 1992). Temperature extremes do not favor, but will

not prevent, emergence of H. gibbicollis adults. Infested wood collected in western

Washington and stored out-of-doors in eastern Washington produced adult beetles

every summer. Temperatures ranged from —27.0° C to 39.5° C within the concrete

enclosure (Table 4). Fewer beetles emerged from out-of-door storage than those

retained within the laboratory, so these extremes may have had a deleterious

effect. Wood moisture is the limiting factor related to larval anobiid survival and

although this remained within the optimal range (13-19%), other conditions were

quite different from those found along coastal areas. Low relative humidity and

low wood moisture found within most inland area buildings may be the major

reason for limiting the distribution of H. gibbicollis.

Acknowledgment

We greatly appreciate the assistance of the many structural pest control operators

in Washington and Oregon who located anobiid-infested structures for this re¬

search. Additionally, we would like to thank Chris Davitt at the Washington State

University Electron Microscopy Center for assistance with the SEM.

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punctatum de Geer (’Totenuhr’). Z. Pflanzenkr. Pflanzenschutz, 50: 159-172.

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Chapman, R. F. 1982. The insects, structure and function (3rd ed). Harvard, Cambridge.

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IV. The effect of type and extent of fungal decay in timber upon the rate of development of

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Fumiss, R. L. & V. M. Carolin. 1977. Western forest insects. USDA For. Serv. Misc. Publ. 1339.

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obiidae). Entomologist, 86: 216-219.

Hickin, N. E. 1960. The problem of wood damage by Anobium punctatum de Geer in the United

Kingdom, with some notes on the current commercial practice of control. Proc. Xlth Int. Cong.

Entomol., 2: 321-326.

Hickin, N. E. 1975. The insect factor in wood decay. Associated Business Programmes, London.

Hickin, N. E. 1981. The woodworm problem (3rd ed). Hutchinson, London.

Jurzitza, G. 1979. The fungi symbiotic with anobiid beetles, pp. 65-76. In L. R. Batra (ed.). Insect-

fungus symbiosis. Allanheld-Osmun, Montclair.

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beetles. Pests, 11: 11-14.

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constant temperatures and humidities. Ann. Entomol. Soc. Am., 63: 617-618.

Payne, T. L. 1974. Pheromone perception, pp. 35-61. In M. C. Birch (ed.). Pheromones. American

Elsevier, New York.

SAS Institute. 1985. SAS user’s guide: statistics, version 5 ed. Cary, North Carolina.

Spiller, D. 1948. Toxicity of boric acid to the common house borer Anobium punctatum DeGeer.

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Spiller, D. 1964. Numbers of eggs laid by Anobium punctatum Deg. Bull. Entomol. Res., 55: 305-

311.

Steinbrecht, R. A. 1987. Functional morphology of pheromone-sensitive sensilla. pp. 353-384. In

G. D. Prestwich and G. J. Blomquist (eds.). Pheromone biochemistry. Academic, Orlando.

Suomi, D. A. 1992. Biology and management of the structure-infesting beetle, Hemicoelus gibbicollis

(LeConte) (Coleoptera: Anobiidae). Ph.D. Dissertation, Washington State University, Pullman.

Suomi, D. A. & R. D. Akre. (in press). Biological studies of Hemicoelus gibbicollis (LeConte) (Co¬

leoptera: Anobiidae), a serious structural pest along the Pacific coast: larval and pupal stages.

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Williams, L. H. 1983. Wood moisture levels affect Xyletinuspeltatus infestations. Environ. Entomol.,

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Received 15 April 1992; accepted 19 March 1993.

PAN-PACIFIC ENTOMOLOGIST

69(2): 171-175, (1993)

DICHAETOCORIS CALOCEDRUS, A NEW SPECIES OF

PLANT BUG ASSOCIATED WITH INCENSE CEDAR

(CUPRESSACEAE), FROM WESTERN NORTH AMERICA

(HETEROPTERA: MIRIDAE: ORTHOTYLINI)

Adam Asquith 1 and John D. Lattin 2

department of Entomology, University of Hawaii, Kauai Research Station,

Kapaa, Hawaii 96746

2 Systematic Entomology Laboratory, Department of Entomology,

Oregon State University, Corvallis, Oregon 97331

Abstract. —Dichaetocoris calocedrus NEW SPECIES, is described. This species is associated with

Calocedrus decurrens (Torrey) Florin (Cupressaceae) in west-central Oregon. Characters defining

the genus Dichaetocoris Knight are discussed and two new combinations are proposed: Orthotylus

ovatus Van Duzee = Dichaetocoris ovatus (Van Duzee) NEW COMBINATION; Orthotylus

vanduzeei Carvalho = Dichaetocoris vanduzeei (Carvalho) NEW COMBINATION.

Key Words. — Insecta, Miridae, Dichaetocoris, Calocedrus

The genus Dichaetocoris was erected by Knight (1968) for species of western

North American orthotylines that differed from Orthotylus by the presence of

both simple and sericeous, decumbent setae on the dorsum. Polhemus (1985)

suggested that Dichaetocoris has two types of simple, unmodified setae. He further

diagnosed Dichaetocoris as lacking sexual dimorphism in hemelytral length, and

being restricted to coniferous host plants. Stonedahl & Schwartz (1986) showed

that Dichaetocoris has, in addition to simple setae, modified, narrowly lanceolate,

sericeous setae, with converging ridges. They also noted that this setal type was

also found in Oaxacacoris Schwartz & Stonedahl and Presidiomiris Stonedahl &

Schwartz, but that these genera are also sister groups to Pseudopsallus Van Duzee,

and not closely related to Dichaetocoris.

Clearly, an extensive analysis of character distributions among western North

American orthotylines is required to better delimit genera and determine generic

relations. Nevertheless, we suggest that the following characters presently define

the genus Dichaetocoris, although all characters may not be unique synapomor-

phies: (1) dorsal vestiture with erect to inclined simple setae, and recumbent,

lanceolate, apically acuminate sericeous setae, with short, converging ridges; (2)

lack of alar sexual dimorphism; (3) weakly convex pronotum, with rounded, lateral

pronotal margins; (4) weakly sclerotized, flattened, or at least basally splayed out

vesical spiculae; and (5) coniferous host plants. Using these criteria, we here

describe a newly discovered species of Dichaetocoris, and transfer to Dichaetocoris,

two other species currently placed in different genera.

The 15 species presently assigned to the genus Dichaetocoris are now known

to occur on at least five genera of conifers: Sequoia Endlicher (Taxodiaceae);

Calocedrus Kurz, Cupressus L., and Juniperus L. (Cupressaceae); and Pinus L.

(Pinaceae). The pines from which Dichaetocoris is known are both pinyon pines,

Pinus edulis Engelmann and P. monophylla Torrey & Fremont.

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Vol. 69(2)

Figure 1. Dichaetocoris calocedrus, dorsal habitus male.

Dichaetocoris calocedrus Asquith & Lattin, NEW SPECIES

Types. — Holotype male. Data: OREGON. DESCHUTES Co.: SE base of Black

Butte, 14 Jun 1990, A. Asquith & J.D. Lattin, ex. Calocedrus decurrens (Torrey)

Florin. Holotype deposited in the collection of the California Academy of Sciences

(CAS), San Francisco. Paratypes. Data: OREGON. DESCHUTES Co.: 9 males,

1993

ASQUITH & LATTIN: A NEW DICHAETOCORIS

173

Figure 2. Dichaetocoris calocedrus, sericeous setae on hemelytra.

10 females, same data as holotype; deposited in Systematic Entomology Labo¬

ratory, Oregon State University (OSU-SEL) and the California Academy of Sci¬

ences (CAS), San Francisco.

Description. —Male (Fig. 1). Length 5.16-5.59 mm; general coloration green fuscous, with hemelytral

margins and cuneus pale; dorsal vestiture with erect or inclined, short setae, dark on fuscous areas

and pale on light colored areas, and recumbent, narrowly lanceolate, sericeous setae, with short,

converging ridges, giving fluted appearance (Fig. 2). Head: Width across eyes 0.82-0.83 mm; width

of vertex 0.39-0.41 mm; yellow-brown; antennae yellow, tinged with brown, segment I 0.41-0.43

mm; segment II 1.52-1.59 mm; segment III 0.93-0.96 mm; segment IV 0.43-0.48 mm; labium reaching

to or beyond apices of metacoxae. Pronotum: Posterior width 1.30-1.35 mm; yellow anterior of calli;

calli and disk yellow green; mesoscutum yellow-green to fuscous medially, yellow laterally; scutellum

yellow fuscous, apex usually pale. Hemelytra: Green fuscous; embolium, corium bordering embolium,

and cuneus pale; membrane grey fuscous, veins dark. Legs: Yellow; tibiae weakly tinged with green;

tarsi, particularly distal segments, variably fuscous. Genitalia: Posteroventral surface of genital capsule

with short, peg-like setae; apex of right paramere squared and strongly serrate (Fig. 3), basal arm with

apex dentate. Left paramere hammer-shaped (Fig. 4); apicodorsal process broad and serrate; apicoven-

tral process narrowly elongate, curved mesally; narrow basal arm present, with two or three small

teeth. Apex of theca acuminate, heavily sclerotized, but entire and slightly convoluted; vesica with 2

large, weakly sclerotized, apically acuminate, trough-shaped spiculae (Fig. 5); ventral spicula one-half

the length of dorsal spicula.

Female.— Length 4.73-5.12 mm; width across eyes 0.81-0.83 mm; width of vertex 0.43-0.44 mm;

antennal segment I 0.41-0.43 mm; segment II 1.46-1.59 mm; segment III 0.83-0.87 mm; segment

IV 0.43-0.44 mm; posterior width of pronotum 1.29-1.36 mm.

Diagnosis. —Dichaetocoris calocedrus NEW SPECIES is most similar to D. van-

duzeei (Carvalho) (see below) in its large size, dark colored scutellum and infus-

cated hemelytral membrane. Dichaetocoris calocedrus is differentiated by its larger

size (total length >4.5 mm), elongate hemelytra, the narrowly hammer-shaped

structure of the left paramere (Fig. 4), and by its fuscous dorsal coloration with

contrasting pale lateral margins and cuneus (Fig. 1).

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Figures 3-5. Dichaetocoris calocedrus, male genitalia. Figure 3. Right paramere, medial view.

Figure 4. Left paramere, medial view. Figure 5. Vesical spiculae. DS = Dorsal spicula, VS = Ventral

spicula.

Etymology. — Named for the plant genus from which this species was collected.

The genus Calocedrus Kurz is sometimes included as a segregate of the genus

Libocedrus Endlicher; however, most recent references consider Calocedrus to be

a distinct genus, containing only those species in the Northern Hemisphere.

Distribution. —Known only from the eastern slopes of the Cascade Mountains

in west-central Oregon.

Discussion. —Dichaetocoris calocedrus is unusual in its broad, trough-shaped

spiculae. Other genera of western Orthotylini with modified setae have a variable

number of narrowed, sclerotized, usually serrate spiculae (Asquith 1991, Stone-

dahl & Schwartz 1986). Some species of Pseudopsallus approach the condition in

D. calocedrus in having broadly trough-shaped spiculae, particularly near their

bases. We examined the spiculae of two other species of Dichaetocoris, both

undescribed, associated with Juniperus L. in western Oregon. Both of these species

have moderately broad spiculae, with weakly recurved lateral margins, but unlike

that of D. calocedrus. In addition, the spiculae of both Juniperus species are serrate

distally.

Material Examined. —Type series.

Dichaetocoris vanduzeei (Carvalho), NEW COMBINATION

Orthotylus cupressi Van Duzee 1925:399.

Orthotylus vanduzeei : Carvalho 1955:225. Replacement name.

Originally described as Orthotylus cupressi by Van Duzee (1925), this name

was preoccupied and the species was given its replacement name by Carvalho

(1955). We examined paratypes of this species in the California Academy of

1993

ASQUITH & LATTIN: A NEW DICHAETOCORIS

175

Sciences and consider it to be a Dichaetocoris, based on the characters described

above. Of all species that we have examined, D. vanduzeei most closely resembles

the new species, D. calocedrus, in its large size, color pattern and general shape

of the left paramere. This species is known only from Cupressus sargenti Jepson

in Marin Co., California.

Dichaetocoris ovatus (Van Duzee), NEW COMBINATION

Orthotylus ovatus Van Duzee 1916:105.

Orthotylus (Melanotrichus) ovatus : Carvalho 1958:117.

Melanotrichus ovatus : Henry & Wheeler 1988:429.

When first described, Van Duzee (1916) allied ovatus with an eastern North

American species, Orthotylus catulus Van Duzee, which is now recognized as

a species of Melanotrichus. Based on our examination of paratypes in the Cal¬

ifornia Academy of Sciences, we found that ovatus clearly belongs to the genus

Dichaetocoris. This species is associated with Juniperus, and is thus far known

only from the original collection near Lake Tahoe, in El Dorado Co., California.

Acknowledgment

We thank Paul H. Amaud, Jr. (California Acadamy of Sciences) for specimens;

Michael D. Schwartz (Canada Agriculture) for manuscript review; Bonnie B. Hall

for her habitus drawing; and Alfred Soeldner for the SEM photographs. This paper

is no. 3764 of the Hawaii Institute of Tropical Agriculture and Human Resources

Journal Series.

Literature Cited

Asquith, A. 1991. A revision of the genus Lopidea Uhler for America North of Mexico (Heteroptera:

Miridae). Koeltz Scientific Books, Koenigstein, Germany.

Carvalho, J. C. M. 1955. Analecta miridologica: miscellaneous observations in some American

museums and bibliography (Hemiptera). Rev. de Chilena Entomologia, 4: 221-227.

Carvalho, J. C. M. 1958. Catalogue of the Miridae of the World. Part III. Orthotylinae. Aequivos

de Museu Nacional. Rio de Janeiro, 47: 1-161.

Henry, T. J. & A. G. Wheeler Jr. 1988. Family Miridae Hahn, 1833 (= Capsidae Burmeister, 1835).

The plant bugs, pp. 251-507. In: Henry, T. J. & R. C. Froeschner (eds.). Catalog of the

Heteroptera, or true bugs, of Canada and the continental United States. E. J. Brill, Leiden, The

Netherlands.

Polhemus, D. A. 1985. A review of Dichaetocoris Knight (Heteroptera: Miridae): new species, new

combinations, and additional distribution records. Pan-Pacif. Entomol., 61: 146-151.

Knight, H. H. 1968. Taxonomic review: Miridae of the Nevada Test Site and the western United

States. Brigham Young Univ. Sci. Bull., 9: 1-282.

Schwartz, M. D. & G. M. Stonedahl. 1987. Oaxacacoris, a new plant bug genus and three new species

of Orthotylini from Mexico (Heteroptera: Miridae). Proc. Entomol. Soc. Wash., 89: 15-23.

Stonedahl, G. M. & M. D. Schwartz. 1986. Revision of the plant bug genus Pseudopsallus Van Duzee

(Heteroptera: Miridae). Am. Mus. Nov., 2842.

Stonedahl, G. M. & M. D. Schwartz. 1988. New species of Oaxacacoris Schwartz and Stonedahl

and Pseudopsallus Van Duzee, and a new genus, Presidiomiris, from Texas (Heteroptera: Miri¬

dae: Orthotylini). Am. Mus. Nov., 2928.

Van Duzee, E. P. 1916. Monograph of the North American species of Orthotylus (Hemiptera). Proc.

Cal. Acad. Sci., 6: 87-128.

Van Duzee, E. P. 1925. New Hemiptera from western North America. Proc. Cal. Acad. Sci., 14:

391—425.

Received 24 April 1992; accepted 1 July 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 176-179, (1993)

FIRST RECORDS OF DICHOCERA (DIPTERA: TACHINIDAE)

REARED FROM CEUTHOPHILUS

(ORTHOPTERA: RHAPHIDOPHORIDAE)

HOSTS IN NEVADA AND NEW YORK

Jett S. Chinn 1 and Paul H. Arnaud, Jr. 2

department of Biology, San Francisco State University,

San Francisco, California 94132

California Academy of Sciences, Golden Gate Park,

San Francisco, California 94118

Abstract.— Dichocera sp. was reared from the camel cricket Ceuthophilus utahensis Thomas

collected in 1990 in Nevada; its puparium is described. La Rivers’ speculation on the likelihood

of C. utahensis occurring in Nevada is substantiated. In 1968, a Dichocera sp. probably lyrata

Williston was reared from Ceuthophilus guttulosus guttulosus Walker in New York.

Key Words. — Insecta, Tachinidae, Dichocera, Rhaphidophoridae, Ceuthophilus, parasitoid, pu¬

parium

We present two rearings of the tachinid genus Dichocera from the rhaphido-

phorid genus Ceuthophilus made over 20 years apart and from opposite sides of

the North American continent. Nevada is newly included in the range of Ceu¬

thophilus utahensis Thomas.

Current records of tachinids reared from the Rhaphidophoridae in North Amer¬

ica include: Meigenielloides cinereus Townsend from Gammarotettix bilobatus

(Thomas) in California (Arnaud 1973: 82), Dichocera orientalis (Coquillett) from

cave crickets (Wood 1987: 1198), and Anisia flaveola (Coquillett) from Ceutho¬

philus latibuli Scudder in Florida. The A. flaveola was cited as Oedematocera

flaveola (Coquillett) (Hubbell 1936: 507, Arnaud 1978: 607); Wood (1985: 20)

synonymized Oedematocera with Anisia. We confirm that Dichocera and Ceu¬

thophilus are sympatric.

Rearing in Nevada

This rearing involves an adult male gracilifemoral “ utahensis ” phase (not ro-

bustifemoral “ uniformis ” phase) of C. utahensis (Hubbell 1936: 68-80) collected

by Graeme Lowe (see material examined), and given to JSC for identification and

observation. Several days later, JSC transferred the camel cricket to a covered

plastic container provided with water, rolled oats, and rabbit feed pellets. At 1430

h (PDT) on 27 Aug 1990, the camel cricket was observed to be grossly debilitated

with a large opening on the left side of its thorax, its left middle and hind legs

severed at the coxae, and its abdomen hollowed. On the floor of the container

was a white dipterous larva. The larva completed pupariation within three hours,

gradually changing from white to red-brown.

Figures 1-5. Puparium of Dichocera sp. Figure 1. Lateral view. Figures 2, 3. Posterior views.

Figure 4. Left posterior spiracular plate. Figure 5. Superior spiracular slit on left posterior spiracle.

1993 CHINN & ARNAUD: CEUTHOPHILUS IN NEVADA AND NEW YORK 177

178

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

The puparium was placed about 1 cm from a small piece of moistened tissue

inside a clean covered plastic container. In this artificial environment, an adult

female fly emerged at approximately 1000 h (PDT) on 29 Sep 1990. It remained

teneral for three days, with its wings not fully expanded when killed. PHA sub¬

sequently identified it as Dichocera sp. Description of the puparium is as follows:

length 8.5 mm, diameter 3.0 mm, smooth, subshining, red-brown; 10 segments

subtly delineated but distinctly discemable (Fig. 1); faint depression on caudal

segment around spiracular plate (Figs. 2, 3); posterior spiracles protuberant (height

approximately 0.2 mm), conical, shiny black (Fig. 1), and approximately 0.36

mm apart at base (Figs. 2, 3); three crescent-shaped slits on each spiracle (Figs.

4, 5).

Material Examined. — Ceuthophilus utahensis, NEVADA. LINCOLN CO.: Rainbow Canyon near

Elgin, 18 Aug 1990, G. Lowe.

Rearing in New York

Correspondence in 1968 and 1969, between Robert E. Silberglied and PHA,

concerning several tachinid rearings included a specimen of Dichocera. At that

time PHA was preparing a manuscript on the hosts of North American Tachinidae,

and Silberglied generously gave him permission to include the rearings in the host

catalog. Because unpublished rearings could not be included in the catalog, we

present this Dichocera record here.

In 1967, at Ithaca, Tompkins County, New York, Silberglied reared Dichocera

probably lyrata Williston, determined by Curtis W. Sabrosky, from a nymphal

Ceuthophilus guttulosus guttulosus Walker.

Discussion

La Rivers’ (1948: 708) conjecture that C. utahensis would likely occur in Nevada

is confirmed by Lowe’s collection of the host and by the collection of a series of

six additional specimens (five females, one male) of the gracilifemoral “ utahensis ”

phase made concurrently at the same locality by Stanley C. Williams, Lowe, and

JSC. The male and two females of this series were parasitized by mites. The

collection site was a habitat of thickets at the base of Rainbow Canyon near

Meadow Valley Wash, along Route 317 (el. 1100-1200 m). This habitat, range,

and spotty distribution are consistent with those mentioned by Hubbell (1936:

68-80) and La Rivers (1948: 708).

Acknowledgment

We thank Robert C. Bechtel (Nevada Department of Agriculture, Reno) for

field guidance as well as supplying research material; Vincent F. Lee (California

Academy of Sciences, San Francisco) for editorial advice; Graeme Lowe (Monell

Chemical Senses Center, Philadelphia) for providing the host specimen; Curtis

W. Sabrosky (Systematic Entomology Laboratory, SEA, U.S. Department of Ag¬

riculture, Washington, D.C.) for identifying the Dichocera from New York; Robert

E. Silberglied posthumously for his Dichocera rearing record; Darrell Ubick (CAS)

for assistance with the illustrations; and Stanley C. Williams (San Francisco State

University) for research guidance and assistance in the field.

1993 CHINN & ARNAUD: CEUTHOPHILUS IN NEVADA AND NEW YORK 179

Literature Cited

Araaud, P. H., Jr. 1973. Meigenielloides cinereus (Diptera: Tachinidae) reared from Gammarotettix

bilobatus (Orthoptera: Gryllacrididae). Pan-Pacif. Entomol., 49: 82-83.

Amaud, P. H., Jr. 1978. A host-parasite catalog of North American Tachinidae (Diptera). U.S.

Dept. Agric., Misc. Pub., 1319.

Hubbell, T. H. 1936. A monographic revision of the genus Ceuthophilus (Orthoptera, Gryllacrididae,

Rhaphidophorinae). Univ. Florida Pub. Biol. Sci. Ser., 2.

La Rivers, I. 1948. Synopsis of Nevada Orthoptera. Amer. Midi. Nat., 39: 652-720.

Wood, D. M. 1985. Tachinidae. A taxonomic conspectus of the Blondeliini of North and Central

America and the West Indies (Diptera: Tachinidae). Mem. Entomol. Soc. Canada, 132.

Wood, D. M. 1987. Tachinidae. pp. 1193-1269. In McAlpine, J. F. (ed.), B. V. Peterson, G. E.

Shewell, H. J. Teskey, J. R. Vockeroth & D. M. Wood (coordinated by). Manual of Nearctic

Diptera. vol. 2. Agriculture Canada Monograph 28: i-vi, 675-1332.

Received 4 May 1992; accepted 1 February 1993.

PAN-PACIFIC ENTOMOLOGIST

69(2): 180-182, (1993)

AN EPIGEAN TYRANNOCHTHONIUS FROM HAWAII

(PSEUDOSCORPIONIDA: CHTHONIIDAE)

William B. Muchmore

Department of Biology, University of Rochester,

Rochester, New York 14627

Abstract. — Tyrannochthonius swiftae NEW SPECIES was found in Ohia litter on the island of

Kauai. It is similar to T. pupukeanus Muchmore from the island of Oahu, but is not at all cave-

adapted.

Key Words. — Arachnida, Pseudoscorpionida, Chthoniidae, Tyrannochthonius swiftae NEW SPE¬

CIES, epigean

Through the efforts of F. G. Howarth and his colleagues, representatives of

three troglobitic species of Tyrannochthonius have been found in the Hawaiian

islands, T. howarthi Muchmore (1979) from Ainahou Petroglyph Cave on Hawaii

Island, T. pupukeanus Muchmore (1983) from Pupukea Lava Tube on Oahu

Island, and T. stonei Muchmore (1989) from Kalu Au Au Dripping Cave on Maui

Island. These species are all definitely cave-adapted, being pallid, with reduced

eyes and attenuated appendages. It must be agreed that they originated from one

or more epigean ancestors, but, until recently, no such “normal” Tyrannochthon¬

ius was known from any of the Hawaiian islands. Urged on by my repeated pleas

to search for litter-dwelling pseudoscorpions by Berlese separation, Sabina Swift

of the Bishop Museum has finally collected a single male of a typical, epigean

species of the genus on Kauai Island; it is new and is described here.

Tyrannochthonius swiftae Muchmore, NEW SPECIES

(Figs. 1, 2)

Type Data. —Holotype male. HAWAII: KAUAI: Hono O Na Pali NAR, 1305

m, Ohia soil and litter, 19 Nov 1990, collected by Sabina F. Swift. Type in the

Bishop Museum, Honolulu (BPBM 15046).

Description. —Male. All parts straw colored. Carapace about square in dorsal view; surface smooth;

epistome small, triangular, with 2 flanking setae; 4 comeate eyes; setae long and prominent; chaetotaxy

d4d-4-4-2-2, the dwarf setae (d) lying anterior to eyes. Abdomen typical; tergal chaetotaxy 4:4:4:4:4:

5:5:5:5:4:T2T:0; sternal chaetotaxy 10:[4-4]:(3)5-5/16(3):(4)6(4): 10:9:9:9:9:8:0:2. Chelicera 0.75 x as

long as carapace; hand with 5 setae; flagellum of ca. 8 pinnate setae; fixed finger with ca. 8 teeth, distal

one largest; movable finger with ca. 10 small teeth; galea represented by a very low elevation; serrula

exterior of 19 or 20 blades. Palp rather long and slender (Fig. 1); femur 1.2x and chela 1.8 x as long

as carapace. Trochanter 1.65 x , femur 4.4 x , tibia 1.75 x and chela 5.25 x as long as broad; hand 1.7 x

as long as deep; movable finger 1.95 x as long as hand. Surfaces smooth; setae slender; 1 prominent

long, heavy seta on medial side of chelal hand at base of fixed finger. Trichobothria as shown in Fig.

2; sb slightly nearer to st than to b. Fixed finger with 27 spaced teeth, tall and sharp distally, low and

rounded proximally, and with 1 or 2 intercalated microdenticles distally; movable finger with 15

pointed teeth and 8 low rounded denticles proximally, and no microdenticles. Legs generally typical,

but rather robust; apex of coxa I with a prominent rounded projection; coxal chaetotaxy 2-2-l:3-0:2-

2(l)-CS:2-3:2-3; setae on apex of palpal coxa long, subequal; each coxa II with 7 or 8 terminally

incised coxal spines (CS). Leg IV with entire femur 2.45 and tibia 4.1 x as long as deep; tactile setae

on tibia and both tarsi. Measurements. Body length 1.45 mm. Carapace length 0.435 mm. Chelicera

length 0.33 mm. Palpal trochanter 0.18/0.11 mm; femur 0.53/0.12 mm; tibia 0.22/0.125 mm; chela

1993

MUCHMORE: A NEW HAWAIIAN TYRANNOCHTHONIUS

181

Figures 1, 2. Tyrannochthonius swiftae NEW SPECIES. Figure 1. Dorsal view of right palp. Figure

2. Lateral view of left chela.

0.79/0.15 mm; hand 0.265/0.155 mm; movable finger 0.52 mm long. Leg IV: entire femur 0.495/

0.205 mm; tibia 0.33/0.08 mm.

Female. — Unknown.

Diagnosis.— A small species in the Hawaiian fauna, about the same size as T.

pupukeanus, from which it differs in having four definitely comeate eyes and more

robust appendages (palpal femur L/B = 4.4, compared with 4.8-5.15 for T. pu¬

pukeanus).

Etymology. — The species is named for S. Swift, who collected the type specimen.

Distribution. —Known only from the type locality.

Remarks. — The discovery of the specimen described above confirms the pres¬

ence of epigean Tyrannochthonius in Hawaii. Continued search of the litter fauna

will undoubtedly turn up representatives of the genus on all of the major islands.

Epigean species of Tyrannochthonius are known from various islands in the

Pacific Ocean west of Hawaii, the nearest being Japan, Guam, New Guinea,

Solomon Islands, New Caledonia, and Kermadec. Tyrannochthonius swiftae is

larger than most of those species, but about the same size as T. japonicus (El-

lingsen), from which it differs in having a distinct epistome and more slender

appendages.

It is interesting that no Tyrannochthonius species is yet known from Pacific

islands directly south or east of Hawaii until the Galapagos Islands, and none has

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

been reported from the eastern shore of the Pacific as far south as Colombia. This

is probably due in large part to lack of collecting and study.

Material Examined.—See types.

Acknowledgment

Many thanks are given to Doris Kist for her expert help with the word pro¬

cessing.

Literature Cited

Muchmore, W. B. 1979. The cavemicolous fauna of Hawaiian lava tubes. 11. A troglobitic pseu¬

doscorpion (Pseudoscorpionida: Chthoniidae). Pacif. Insects, 20: 187-190.

Muchmore, W. B. 1983. The cavemicolous fauna of Hawaiian lava tubes. 14. A second troglobitic

Tyrannochthonius (Pseudoscorpionida: Chthoniidae). Int. J. Entomol., 25: 84-86.

Muchmore, W. B. 1989. A third cavemicolous Tyrannochthonius from Hawaii (Pseudoscorpionida:

Chthoniidae). Pan-Pacif. Entomol., 65: 440-442.

Received 28 May 1992; accepted 1 September 1992.

PAN-PACIFIC ENTOMOLOGIST

69(2): 183-189, (1993)

NEW SPECIES OF PERDITA ( PYGOPERDITA ) TIMBERLAKE

OF THE P. CALIFORNICA SPECIES GROUP

(HYMENOPTERA: ANDRENIDAE)

Terry Griswold

USDA, ARS, Bee Biology & Systematics Laboratory,

Utah State University, Logan, Utah 84322-5310

Abstract. —Three new species of Perdita (Pygoperdita ) of the P. californica group are described

from the southwestern United States. Perdita meconis NEW SPECIES, from the Mojave Desert,

is associated with two genera of Papaveraceae, Argemone and the endangered dwarf bearclaw

poppy, Arctomecon humilis Coville. Perdita ute NEW SPECIES, from the San Rafael Desert of

central Utah, is also associated with Argemone. The floral association of P. angellata NEW

SPECIES, from the Colorado Plateau of northern Arizona, is unclear. A key to males is presented.

Key Words. — Insecta, Andrenidae, Perdita, Papaveraceae, Argemone, Arctomecon

Recent collections of pollinators that were made in connection with studies on

the pollination of the endangered dwarf bearclaw poppy, Arctomecon humilus

Coville, yielded a new species of Perdita (.Pygoperdita ) Timberlake. It is described

here to make the name available for those studies. Two additional closely related

species, one needed for a study in progress on the fauna of the San Rafael Desert,

Utah, are also described.

Males of the three species described here, together with P. argemones Timber-

lake, form a subgroup of the P. californica species group of P. {Pygoperdita) that

can be distinguished from all other members of the P. californica group by the

structure of tergum 7 (T7). In these species, the apical lobes of T7 are wide (nearly

horizontal), the lateral preapical angles are acute, and there is no transverse preap-

ical carina separating the base of the segment from the apical lobes.

Characterization of the females is difficult. There is currently no way to distin¬

guish between females of the P. interrupta Cresson and P. californica species groups

(Timberlake 1956). So it should not be surprising that no unique combination of

characters could be found to distinguish females of this subgroup from other

species of the P. californica group. Females of all four species can be separated

from most other P. (.Pygoperdita ) by the combination of obscure facial fovea,

sparse scutal punctation, distinctly maculated metasoma, and a complete basitibial

plate on the hind leg. However, P. cowaniae Timberlake, P. duplonotata Tim¬

berlake, P. fallugiae Timberlake, P. distropica Timberlake, P. mohavensis Tim¬

berlake, and P. robustula Timberlake also possess these traits. Therefore, no key

to the females is presented here; rather the position of each species in Timberlake’s

1956 key is given.

Key to Males

1. Facial marks yellow; galea lightly shagreened . 2

- Facial marks white; galea polished. 3

2(1). Frons, scutum shagreened anteriorly; metasoma dark with yellow markings;

apical lobes of T7 thickened apically. meconis NEW SPECIES

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Frons, scutum polished anteriorly; metasoma uniformly with a red hue,

except for small dark marks; apical lobes of T7 not thickened apically ...

. argemones Timberlake

3(1). Facial fovea dull; scutum uniformly green; light maculations of metasoma

broad, on T2-3 encircling oval lateral spots; apical lobes of T7 not thickened

apically . ute NEW SPECIES

- Facial fovea shiny; scutum centrally black with purple reflections; macu¬

lations of metasoma narrow, on T2-3 not encircling oval lateral spots; apical

lobes of T7 thickened apically. angellata NEW SPECIES

Perdita meconis, NEW SPECIES

(Figs. 7-9, 12)

Types. —Holotype male. UTAH. WASHINGTON Co.: Warner Ridge, Beehive

Dome, 19 May 1988, 8:30-9:00 AM, Arctomecon humilis Coville, B. Snow. Ho¬

lotype deposited in USDA Bee Biology and Systematics Collection, Logan, Utah.

Paratypes: CALIFORNIA. SAN BERNARDINO Co.: Cottonwood Wash, 768 m

(2520 ft), T9N RUE Sec. 3, 10 May 1982, Argemone, T. Griswold, 5 males, 1

female; same except 2 Jun 1980, no floral record, 1 female; Kelso Dunes, 664 m,

(2180 ft), T10N R13E Sec. 7, 15 May 1980, mating pair, T. Griswold, 1 male, 1

female; same except Argemone, 14 males; Kelso Dunes, 655 m (2150 ft), T10N

R13E, 2 May 1980, Argemone, T. Griswold, 4 males; Winston Wash, 588 m

(1930 ft), T10N RUE Sec. 3, 15 Apr 1980, Argemone, T. Griswold, 5 males.

UTAH. WASHINGTON Co.: Same data as holotype, 1 male, 2 females; same

except 20 May 1988, 2 males, 3 females; same except 20 May 1988, 8:00-8:30

AM, 1 male, 1 female; same except 20 May 1988, 9:00-9:30 AM, 1 male, 1

female; same except mating pair, 18 Apr 1989, 8-10 AM, 1 male, 1 female; same

except 24 Apr 1989, 11:30-11:40 AM, 1 female; same except 24 Apr 1989, 10:

25-10:30 AM, 1 male. Paratypes deposited in USDA Bee Biology and Systematics

Collection, Logan, Utah, and University of Kansas, Lawrence.

Male. Length 5 mm. Forewing length 4 mm. Head and mesosoma dark green except: propodeum

blue-green; pale yellow on mandible, labrum, face below level of antenna, ventral triangular area on

gena, submedial transverse line on pronotal collar, pronotal lobe. Antenna yellow below, brown above.

Legs black except: pale yellow on femora apically, anterior stripe on fore- and midtibia, fore- and

midtarsi; hindtarsi dark brown. Wings hyaline, veins milky white except subcosta brown. Metasoma

with T1 dark green turning brown on posterior margin; T2 with basal yellow stripe narrowly broken

medially, pair of lateral very dark brown oval spots joined medially by narrow brown stripe, posterior

third of segment amber; T3 similar but oval spots less well defined, brown stripe evanescent; T4 amber

except for ill-defined, lighter brown oval spots; T5-7 amber. SI black; S2-6 amber. Frons strongly

shagreened, moderately covered with fine punctures. Mesosoma lightly shagreened except shiny medial

portion of scutum and scutellum; scutal punctures fine, sparse especially medially. Head broader than

long, inner orbits parallel. Facial fovea dull, obscure. Galea lightly shagreened, as long as eye length,

pointed apically. T7 as in Fig. 7, apical lobes oblique, almost vertical, in posterior view, apically

thickened. S8 as in Fig. 9. Genitalia as in Fig. 8.

Female.— Length 6.5-7 mm. Forewing length 4.5-5 mm. Color as in male except pale yellow

markings of head and mesosoma restricted to mandible, apical spot on labrum, clypeus except for

pair irregular, often interrupted, vertical lines, pair very narrow supraclypeal lines, triangular paraocular

area. Legs dark brown except for pale yellow on apex of fore- and midfemora and anterior stripe on

foretibia. Metasomal terga dark brown except with green caste on Tl, T2 with basal stripe narrowly

interrupted medially, T3-4 similar but with progressively wider marks; T5 mostly yellow except for

basolateral spot and subapical area (Fig. 12). Sterna amber-yellow except SI brown, S2-4 with diffuse

lateral brown spots. Punctation and sculpture as in male. Head distinctly wider than long. Clypeus

1993

GRISWOLD: NEW PERDITA SPECIES

185

Figures 1-9. Male metasomal structures. Figure 1 .Perdita ute, T7 in dorsal view. Figure 2. Perdita

ute, genitalia in dorsal view. Figure 3. Perdita ute, S8 in ventral view. Figure 4. Perdita angellata, T7

in dorsal view. Figure 5. Perdita angellata, genitalia in dorsal view. Figure 6. Perdita angellata, S8 in

ventral view. Figure 7. Perdita meconis, T7 in dorsal view. Figure 8. Perdita meconis, genitalia in

dorsal view. Figure 9. Perdita meconis, S8 in ventral view.

dentate adjacent to labrum. Facial fovea linear, extending from level of lower margin of antennal

socket to approximately half distance between antennal socket and median ocellus. Pygidial plate

rather abruptly narrowed apically, strongly curved ventrally in lateral view.

Diagnosis.— See key.

Variation.— Males range in size from 4.5-5.5 mm long. Extent of maculations

varies in males. Some individuals have the paraocular mark reduced adjacent to

the subantennal suture. General metasomal coloration is darker in some individ¬

uals.

186

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Figures 10-13. Female metasoma, dorsal view showing markings. Figure 10. Perdita angellata.

Figure 11. Perdita argemones. Figure 12. Perdita meconis. Figure 13. Perdita ute.

1993

GRISWOLD: NEW PERDITA SPECIES

187

Etymology. — From the Latin “mecon,” meaning poppy, because this bee is

apparently limited in pollen collection to Papaveraceae.

Distribution. —Known only from the eastern Mojave Desert, where it is asso¬

ciated with Arctomecon and Argemone (Papaveraceae).

Discussion. — In the key to P. (Pygoperdita ) (Timberlake 1956), males of P.

meconis key to couplet 73, where they do not agree well with either part of that

couplet. The female keys to couplet 23, where it may be distinguished from the

subspecies of P. wyomingensis Cockerell (as P. sculleni Timberlake subspecies;

see Timberlake 1968) by the following: longer mouthparts, scutum lightly sha-

greened anteriorly, scutal punctation more dense, T4 mostly and T5 entirely

yellow.

Material Examined.—See types.

Perdita ute, NEW SPECIES

(Figs. 1-3, 13)

Types. — Holotype male. UTAH. EMERY Co.: 5.1 air km (3.2 mi) NE Little

Gilson Butte, 1524 m (5000 ft), 3 Jun 1981, F. D. Parker. Holotype deposited in

USDA Bee Biology and Systematics Collection, Logan, Utah. Paratypes all: UTAH.

EMERY Co.: same data as holotype, 3 males, 14 females; same except, 3 Jun

1991, Argemone corymbosa Greene, T. Griswold, 2 males; same except 30 May

1991, 1 male; near Little Gilson Butte, 1554 m (5100 ft), 3 Jun 1991, Argemone

corymbosa, T. Griswold, 4 males; same except, 13 Jun 1991, 1 female; E edge

San Rafael Reef, 3.2 km (2 mi) S Interstate Hwy-70, 1347 m (4420 ft), 3 Jun

1991, T. Griswold, 1 female. Paratypes in USDA Bee Biology and Systematics

Collection, Logan, Utah, and University of Kansas, Lawrence.

Male. — Length 4.5 mm. Forewing length 4 mm. Head and mesosoma dark blue-green except: cream-

colored markings on mandible, labrum, clypeus except for pair small dark dots, subantennal area,

pair spots on supraclypeal area, elongate triangular ventral area on gena, small spot on pronotal lobe.

Antenna pale yellow below, dark brown above. Legs dark brown except: pale yellow on femora apically,

fore- and midtibia except posterior longitudinal stripe, narrow ventral stripe on posterior tibia, fore-

and midtarsi; hindtarsi light brown. Wings hyaline, veins off-white except subcosta dark brown.

Metasoma dark brown (except T1 almost entirely dark blue-green), with pale yellow marks as follows:

T1 on extreme apicolateral margin, T2 wide basal stripe very narrowly interrupted medially, narrow

subapical line medially, small subapical patch laterally; T3 like T2 but light areas coalescing to form

triangular medial and oval lateral dark spots; T4 as in T3 but dark lateral spot not margined posteriorly

by thin yellow line; T5 with wide V-shaped medial mark and lateral spot, T6 subapical margin; T7

amber. SI-6 with subapical light bands. Frons strongly shagreened, moderately covered with fine

punctures. Mesosoma lightly shagreened except scutellum shiny medially; scutal punctures fine, sparse

especially medially. Head broader than long, inner orbits parallel. Facial fovea dull, obscure. Galea

polished, nearly as long as eye length, apically pointed. T7 as in Fig. 1, apical lobes oblique, almost

vertical in posterior view, apically not thickened. S8 as in Fig. 3. Genitalia as in Fig. 2.

Female.— Length 5.5 mm. Forewing length 4.5 mm. Color as in male except quadrangular area

posteriorly on scutum, scutellum black; cream markings restricted to mandible, labrum laterally,

clypeus except pair vertical stripes, triangular paraocular area. Legs dark brown except pale yellow on

apices of femora, anterior portion of fore- and midtibia. T1 dark blue-green except for 2 pair pale

yellow spots apically; T2-5 pale yellow except: white medially on T4, light brown basally and apically,

dark brown oval spots apicolaterally on T2-4 and subapical area medially on T2-3 (Fig. 13). Sterna

amber except for diffuse pale yellow transverse stripes on S3-4. Punctation and sculpture as in male.

Head distinctly wider than long. Clypeus dentate adjacent to labrum. Facial fovea linear, extending

from level of middle of antennal socket to approximately half distance between antennal socket and

median ocellus. Pygidial plate evenly narrowed apically, slightly curved ventrally in lateral view.

188

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

Diagnosis. — See key.

Variation. — Light metasomal markings of one male more extensive than those

of holotype. Females vary slightly in extent of metasomal maculations.

Etymology. —Named for the Ute Indians, who inhabited the San Rafael Desert.

Distribution. — Known only from the sand dune areas of the San Rafael Desert,

Colorado Plateau.

Discussion. — Males key to couplet 73 in the key to Perdita (.Pygoperdita ) (Tim-

berlake 1956) where they do not agree well with either option. The female keys

to couplet 22 (if you assume the black on the scutum to be limited, as in P.

duplonotata Timberlake) where it differs from both P. nitens Timberlake and P.

duplonotata by the continuous, or at most very narrowly interrupted, light meta¬

somal bands. The abdominal markings of P. ute are quite similar to those of P.

argemones (Fig. 11), but the background color of the first few terga is black, not

dark brown, and the light markings of T2-4 are larger, with the transverse basal

marks usually joining the posterolateral ones.

Material Examined.— See types.

Perdita angellata, NEW SPECIES

(Figs. 4-6, 10)

Types.— Holotype male. ARIZONA. COCONINO Co.: 32.2 km (20 mi) N

Cameron, 3 May 1972, Sphaeralcea, F. Parker, P. Torchio, G. Bohart. Paratypes,

same data as holotype, 2 males, 1 female. Holotype and paratypes in USDA Bee

Biology and Systematics Collection, Logan.

Male. —Length 5.5 mm. Forewing length 4.5 mm. Head with frons and vertex olive green; gena,

except ventrally, dark green; paraocular area above white mark dark blue; mandible except apically,

labrum, clypeus except for pair dark dots, emarginate supraclypeal mark, subantennal area, quadran¬

gular mark on paraocular area with short narrow extension along eye, small triangular mark on lower

gena white. Antenna yellow below, brown above. Mesosoma dark green except for quadrangular

purplish area posteriorly on scutum, darker bronze scutellum. Wings hyaline, veins light brown except

subcosta dark brown. Legs brown, except yellow apically on femora, and anteriorly on fore- and

midtibia, fore- and midtarsi yellow-brown. Terga dark brown except T1 with greenish reflections, pale

yellow markings on lateral comers of T1-5 and linear, medially interrupted, transverse basal bands

on T2^L SI dark brown, S2-6 yellow-brown. Frons strongly shagreened, moderately covered with

fine punctures. Mesosoma lightly shagreened except shiny medial portion of scutum and scutellum;

scutal punctures fine, sparse especially medially. Head broader than long, inner orbits slightly con¬

verging above. Facial fovea shiny, distinct. Galea polished, as long as eye length, pointed apically. T7

as in Fig. 4, apical lobes oblique in posterior view, thickened apically. S8 as in Fig. 6. Genitalia as in

Fig. 5.

Female .—Length 6.5 mm. Forewing length 4.5 mm. Color as in male except paraocular area less

strongly blue, white markings of head and mesosoma restricted to mandible basally, lateral quadrate

mark on clypeus, triangular paraocular mark. Legs dark brown except for pale yellow on apex of fore-

and midfemora and anterior stripe on foretibia. Terga brown except: T2 with irregular, narrow basal

stripe widely interrupted medially, small apicolateral spot; T3 similar but with wider regular basal

mark joining apicolateral spot; T4 as in T2 except basal stripe not as narrow, not irregular; T5 with

small apicolateral spot. Sterna brown. Punctation and sculpture as in male. Head distinctly wider than

long. Clypeus dentate adjacent to labrum. Facial fovea linear, extending from level of lower margin

of antennal socket to midpoint between antennal socket and median ocellus. Pygidial plate evenly

narrowed apically, slightly curved ventrally in lateral view.

Diagnosis.— See key.

Variation. — Extent of facial maculations is reduced in one paratype. The basal

maculations of the metasomal terga are also reduced in the paratype males.

1993

GRISWOLD: NEW PERDITA SPECIES

189

Etymology.— From the Latin “angellus,” small angle, for the distinctive small

lateral angles of male T7 which distinguish this subgroup from other P. (Pygo-

perdita).

Distribution. — Known only from the southern portion of the Colorado Plateau

in northern Arizona.

Discussion. — Males of Perdita angellata key to couplet 73 in Timberlake’s 1956

key to the species of Perdita (Pygoperdita ), where they do not agree well with

either option. The female keys to couplet 22 (if the first half of couplet 11 is

chosen), where it differs from both P. nitens Timberlake and P. duplonotata

Timberlake by the completely black medial portion of the clypeus, the reduced

markings of T4 and the absence of light markings on T5. If the second half of

couplet 11 is chosen, it keys to P. mohavensis Timberlake in couplet 35, where

it differs by its shorter tongue.

Material Examined. —See types.

Acknowledgments

Thanks to Bryan Danforth and Roy Snelling for reviewing the manuscript.

Bonnie Snow and Susan Geer, under the supervision of Vincent Tepedino, con¬

ducted the field work which netted the type series of Perdita meconis. I also thank

Ralph Gierisch, retired BLM botanist, for bringing the Arctomecon humilis site

to their attention. Work was funded by the USD A-APHIS Grasshopper IPM

project. Marianne Cha Filbert produced the illustrations.

This is a contribution from Utah Agricultural Experiment Station, Utah State

University, Logan, UT 84322-5310, Journal Paper No. 3952, and USDA, Ag¬

ricultural Research Service, Bee Biology & Systematics Laboratory, Utah State

University, Logan, UT 84322-5310.

Literature Cited

Timberlake, P. H. 1956. A revisional study of the bees of the genus Perdita F. Smith, with special

reference to the fauna of the Pacific Coast. Part II. Univ. Calif. Publ. Entomol., 11: 247-350.

Timberlake, P. H. 1968. A revisional study of the bees of the genus Perdita F. Smith, with special

reference to the fauna of the Pacific Coast. Part VII. Univ. Calif. Publ. Entomol., 49: 1-196.

Received 17 July 1992; accepted 1 March 1993.

PAN-PACIFIC ENTOMOLOGIST

69(2): 190, (1993)

Scientific Note

MIMOSESTES NUBIGENS (MOTSCHULSKY)

ESTABLISHED IN CALIFORNIA

(COLEOPTERA: BRUCHIDAE)

Mimosestes nubigens (Motschulsky) was recently sent to us for determination;

these were reared from the seeds of Acacia farnesiana (L.) Willdenow from Bor¬

rego, San Diego County, California. This is the first record of this bruchid being

collected well into California. Although M. nubigens was reported from Calexico,

California (Kingsolver, J. M. & C. D. Johnson. 1978. USDA Tech. Bull., 1590),

it was not considered to be well established in California because Calexico is on

the border with Mexico. Because A. farnesiana is a popular ornamental plant that

is used widely in California, the bruchid should be expected to attack its seeds in

other areas of the state.

An area of a freeway median (1-40) from 8-12.8 km (5-8 mi) SE of Needles,

San Bernardino County, California has been planted with A. farnesiana, appar¬

ently as an ornamental plant and to prevent erosion. Since December, 1974, and

most recently on 11 Mar 1991, the seeds of these plants were sampled several

times for the presence of bruchids, but no M. nubigens have been reared from

them. On the contrary, Mimosestes amicus (Horn) was reared from its seeds

collected in December, 1974 (Kingsolver & Johnson 1978). Mimosestes amicus

only occasionally feeds in the seeds of this acacia, and its presence in that locale

can be accounted for by the nearby palo verde ( Cercidium floridum Bentham), its

more favored host. Seeds collected on 11 Mar 1991 have eggs glued to them,

which we believe to be Stator limbatus (Horn), also a bruchid predator of seeds

of C. floridum. No adults emerged from them, presumably because seeds of A.

farnesiana have toxins or other inhibitors that prevent S. limbatus from feeding,

even in the laboratory (Johnson, C. D. 1981. Environ. Entomol., 10: 857-863).

Mimosestes nubigens is also established in Hawaii, Arizona, Texas, Florida,

and has a distribution to Brazil (Kingsolver & Johnson 1978).

Material Examined. —Mimosestes nubigens : CALIFORNIA. SAN DIEGO Co.: Borrego (1325 Bor¬

rego Valley Rd), 23 Jan 1991, ex seeds Acacia farnesiana.

Acknowledgment. — We thank Margaret Johnson for assistance in the field and

Richard M. Persky for sending the specimens to us.

Clarence Dan Johnson 1 and Terry N. Seeno, 2 1 Department of Biological Sci¬

ences, Northern Arizona University, Flagstaff, Arizona 86011-9989; 2 Insect Tax¬

onomy Laboratory, Department of Food and Agriculture, 1220 N Street, Sacra¬

mento, California 95814.

Received 30 April 1991; accepted 16 July 19912

1 This manuscript was misplaced during handling by the editor—Ed.

PAN-PACIFIC ENTOMOLOGIST

69(2): 191-192, (1993)

Book Review

Hanski, Ilkka & Yves Cambefort (Eds.). 1991. Dung Beetle Ecology. Princeton

University Press, Princeton, New Jersey, xiii, 481 p., illus. (ISBN 0-691-08739-

3) $60.00.

This book, with its brief title and dust jacket illustration of a world globe covered

with dung beetles, is a surprisingly complete review of a vast subject. The spe¬

cialized subject of the book is carefully placed in the context of general ecological

principles, and the evolution and systematics of scarab beetles.

The editors have done an excellent job of organizing and structuring the book.

There are three parts: (1) Introduction, (2) Regional Dung Beetle Assemblages,

and (3) Synthesis. In twenty chapters, with a total of fifteen contributors, these

topics are covered with a satisfying thoroughness. For example, the regional cov¬

erage does not leave out any major geographic area or faunal region. There is a

smoothness from chapter to chapter that presents a unified whole belying the

multiple authorship.

The seemingly unpleasant subject of animal excrement and the organisms that

feed on it, or live in it, is actually made interesting in this book. A non-specialist

with a general interest in ecology will find it readable and informative. The in¬

troduction discusses the ephemeral and patchy nature of the dung habitat and the

problems presented to organisms that exploit it. After discussing the general fauna

of dung, the authors justify focusing on only one component: the scarab dung

beetles. According to the authors, dung beetles are the dominant fauna in dung

and “comprise a distinct guild of their own and exhibit the strongest interspecific

interactions among themselves.” Given the rich variety and abundance of mam¬

malian dung, the next issue is the reason for the dominance of only a few sub¬

families of one family of beetles. Here, the authors discuss the preadaptation of

humus feeding scarabs that evolved prior to the dominance of mammals (but

what fed on dinosaur dung?). As large, herbivorous and omnivorous mammals

evolved, the scarabs were ready to move into the new resource and were able to

outcompete other insects.

The book is well illustrated with tables, graphs and diagrams. The many methods

of resource exploitation by dung feeding scarabs are thoroughly explored. A unique

index is particularly noteworthy. Every genus of dung beetle is listed with the

number of species known, tribe, and pages referred to in this book. Absence of a

page reference to a genus is an indicator of a lack of published information on

the genus.

A systematist may get picky about the lack of indication of authorities for

identification, or place of deposit of voucher specimens. However, a review work

of this nature should not be expected to contain such detailed information that

would unnecessarily expand its size and cost. Tables of genera and species in the

appendices do have author citations. The classification of the Scarabaeoidea adopted

is one favored by European workers, in which sixteen families of dung beetles are

recognized. Most American workers recognize only one family (Scarabaeidae).

192

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 69(2)

Holm and Marais in their recent work on the Fruit Chafers of Southern Africa

argue strongly against the splitting of Scarabaeidae into multiple families.

Dung Beetle Ecology is a significant contribution to the literature of ecology

and evolution. Its price is not out of line with current trends. It could be suc¬

cessfully utilized as a supplementary text in college courses.

Kirby W. Brown, San Joaquin County Agricultural Commissioner's Office, P.O.

Box 1809, Stockton, California 95201.

PAN-PACIFIC ENTOMOLOGIST

69(2): 192, (1993)

Book Review

Evenhuis, Neal L. (Ed.). 1989. Catalog of the Diptera of the Australasian and

Oceanean Regions. Bishop Museum Press and E. J. Brill, Honolulu, Hawaii,

1155 p. Price $85 (ISBN-0-930897-37-4).

This work is an important milestone toward the complete cataloging of all the

species of Diptera in the world. The only zoogeographical regions yet to be finished

are the Palaearctic and Neotropical.

This catalog covers Australia, Tasmania, New Guinea, New Zealand and the

Pacific islands of Hawaii, Guam, eastern Indonesian Archipelago to French Pol¬

ynesia and Easter Island. In Appendix I, it lists taxa from Antarctica and the

surrounding subantarctic islands. Fossil Diptera of Australasia and Oceania are

covered in Appendix II.

Each taxon is classified under family, genus and species, with other supergeneric

names given where appropriate. In many cases synonymies are listed for genera

and species. The large Literature Cited section is a source of additional infor¬

mation. An adequate index gives valid species names, synonyms and higher

categories.

The author provides a very helpful section describing and mapping the many

far-flung islands covered in this catalog, giving the most up-to-date name for each.

Much credit is due Neal Evenhuis, for seeing the need for this work, for his

assigning the various dipterous families to fifty-three taxonomists throughout the

world, and for his superb job of coordinating all of the accumulated information

into a very usable catalog. The contributing taxonomists are from Australia, Brazil,

Canada, Czechoslovakia, Denmark, England, France, Germany, Japan, Nether¬

lands and the United States.

This work documents our present knowledge of the named species of Diptera

of the Australasian and Oceanean Regions, and provides an excellent base to

which future taxa can be added.

F. L. Blanc, California Academy of Sciences, Department of Entomology, Golden

Gate Park, San Francisco, California 94118-4599.

PAN-PACIFIC ENTOMOLOGIST

69(2): 193, (1993)

Book Review

Armitage, Brian J. 1990. Diagnostic Atlas of North American Caddisfly Adults.

1. Philopotamidae (2nd ed.). The Caddis Press. Athens, Alabama. 72 p.

A worthwhile book with useable illustrated keys, diagnostic descriptions and

illustrations of the genitalia of the males and, when known, the female. However

in the rewrite an error crept in. In the first edition, Chimarra angustipennis was

noted as occurring in California, but not here. This was compounded by the

synymizing with it of C. siva with its Calif, type locality. The other problem was

the inadvertent absence of Dolophilodes andora, D. Columbia and Wormaldia

laona (Denning, D. G. 1989. “Eight new species of Trichoptera.” Pan.-Pacif.

Entomol., 75: 123-131).

The work is a major convenience for researchers, an aid in faunal surveys and

will permit beginners ready entry to this group. It is available from author at Ohio

Biological Survey, Ohio State Univ. 1315 Kinnear Rd., Columbus, Ohio 43212-

1192

Donald J. Burdick, Dept, of Biology, California State University-Fresno, Fresno,

California 93740-0073.

PAN-PACIFIC ENTOMOLOGIST

69(2): 194-198, (1993)

THE PAN-PACIFIC ENTOMOLOGIST, FORMATS:

TAXONOMIC MANUSCRIPTS AND LOCALITY DATA

Taxonomic Format

The Pan-Pacific Entomologist requires taxonomic articles to conform to a standardized format and

paragraph sequence that promotes a uniform appearance and order within the journal. The taxonomic

format applies to any manuscripts that: (a) are taxonomic in nature, providing or discussing nomen-

clatural reassignments, synonymies, formal descriptions, or diagnoses, or (b) cite locality data for

specimens or geographic information for types. The taxonomic format and paragraph order is listed

below:

(1) Taxonomic Name heading: (Required initial heading for section. Centered heading.)

Name underlined, with taxonomic author(s), followed by a new status descriptor in capital letters

(i.e., NEW GENUS, NEW SPECIES, NEW STATUS, NEW COMBINATION), where appropriate.

When citing species names that have been previously reassigned to new genera, place only the

taxonomic authors name in parentheses but not the date, if cited, of the species description [i.e.,

Essigella califomica (Essig), 1909; not (Essig, 1909) or (Essig 1909)]; for any author citations that

include the year, list the reference in the Literature Cited section. Examples:

Ralus thermophilus Geptor, Holling & Zalick, NEW SPECIES

Ralus philpoti (Donker), 1967, NEW COMBINATION

(2) Synonymy listings. (Optional. Left hanging paragraph.)

These paragraphs end in NEW SYNONYMY, when appropriate. List all citations in the Lit¬

erature Cited section. If citing geographic data (i.e., type locality) associated with a name, use the

locality data format (below). Depository abbreviations may be used for any types for synonyms

mentioned under synonymy listings. Avoid discussions of synonyms under synonymy listings; if

they must be discussed, do so in a Synonyms or Discussion paragraph after the Diagnosis paragraph.

Synonymy examples:

Ralus thermadorus Gustof, 1955: 304-305. Type locality: CALIFORNIA. El DORADO Co.:

Placerville. Holotype deposited BM[NH1. NEW SYNONYMY

Ralus hobarti Anderson, 1923: 34-36.

Ralus querteri (Zippier), 1912. Lectotype: AUSTRALIA. NEW SOUTH WALES: Newcastle, 11

Dec 1889, deposited USNM. NEW SYNONYM

(3) Types paragraph. (Required paragraph before description if a new taxon is being originally described,

but optional if only a new form [morph, sex, etc.] is described for an existing taxon. Indented paragraph

format. The Types paragraph is designated “Type-Species” for a genus description, and then lists the

generotype.)

All type data must: (a) conform to the locality data format [see Material Examined paragraph

and locality data format below]; or (b) alternatively, for holo-, alio-, lecto- or neotypes [not para-

types], data may be quoted [within quotation marks] from the data label. Spell out the depository

for holo-, alio-, lecto- or neotypes and list the city in which it occurs; depositories for paratypes

may be indicated by abbreviations that are defined earlier in the Methods sections. List all types,

including paratypes, in the Types paragraph. Use a format for this paragraph that is reasonably

similar to the following:

Types. —Holotype, female; data: CALIFORNIA. SAN BERNARDINO Co.: 3 km S of Anytown,

2200 m el, 16 Sep 1977, A. H. Geptor, Pinus lambertiana Douglas; deposited: British Museum

(Natural History), London. Paratypes: same data as holotype, 30 females, 6 males; deposited: U.S.

National Museum of Natural History, Washington, D.C.

(4) Description paragraph(s). (Required paragraph(s) for formal description statements for any new or

existing taxon, but optional if no formal description statement is desired for an existing taxon [e.g.,

a taxonomic review]. Indented paragraph format [reduced to 8 pt type in the journal].)

1993

TAXONOMIC/LOCALITY DATA FORMATS

195

Use a single, separate paragraph for the description of each sex, morph or life stage; do not

describe various body parts in separate paragraphs. Alternatively, a general (unisex) description,

occurring as one paragraph, may be followed by separate paragraphs for males and females, noting

only their differences. Maintain the same order for morphological sequences among descriptions

of multiple taxa. Define any specialized abbreviations in the Methods section.

Description. —Description requirements: (A) Description in telegraphic style [minimum use of

words, especially connectives]. (B) Avoid “-ish” endings for colors, instead describe colors more

accurately [i.e., not “reddish brown” but “red-brown” or “brown with a light red hue,” not

“blackish” but “black” “with faint black cast”]. (C) Describe dimension comparisons or ratios

in quasi-formula format using decimals and “x” between descriptors [i.e., “wing width 3.5 x length”

rather than “wing width three and one-half times its length”]. (D) Use Arabic numerals for all

numbers, including those under ten [i.e., “3-5 setae,” “2-58 pores,” “4 mm long,” “setal number

formula 2:4:4:5:11,” “abdominal segment 4”]; alternatively, if desired, Roman numerals may be

used for body segments of components [i.e., “abdominal segment IV,” “antennal segment II”]. (E)

Fractions should be expressed as word equivalents or decimals [i.e., “0.25” or “one-quarter,” not

“1/4”], and should have “one-” inserted where it is implied [i.e., “on distal one-third” preferably

to “on distal third”]. (F) Avoid English directional descriptors, using Latin instead [i.e., “mesal”

or “medial,” not “inner”; “distal” or “lateral,” not “outer”; “dorsal” or “ventral,” not “upper”

or “lower”]. (G) Place measurement units after each measurement, do not state “all measurements

in mm” and then list only numbers [i.e., “leg lengths: femur 5.0 mm, tibia 3.0 mm”; not “leg

lengths (mm): femur 5.0, tibia 3.0”].

(5) Diagnosis paragraph: (. Required paragraph after description if a new taxon is being originally

described, but optional if only a new form [e.g., sex, morph, stage] is described for an existing taxon.

Indented paragraph format.)

Diagnosis. —The diagnosis, labeled as such, for newly described species should state, using

nontelegraphic style, only those traits necessary to distinguish the new species. For example: “ Ralus

thermophilus can be distinguished from all other Ralus by its unique combination of . . .” or

“ Ralus thermophilus very closely resembles R. strobus Alexander, but can be distinguished by its

. . .” Do not incorporate non-diagnosis discussions in the diagnosis. If a key is provided in the

manuscript, you may chose to simply state “See key” in the Diagnosis paragraph, rather than

repeat the diagnostic features there.

(6) Various miscellaneous paragraph(s): (Optional. Indented paragraph format.)

Discussion. —These optional side-headed paragraphs (e.g., [in preferred order] “ Synonyms. -,”

“ Distribution. -,” “ Hosts. -,” “ Discussion. -,” “ Etymology. -,” etc.) may be added after the Diagnosis

paragraph, to discuss and draw attention to particular information. Because purely diagnostic

statements go in the Diagnosis paragraph, mention of diagnostic traits in discussion paragraphs

may be redundant unless other qualities (e.g., apomorphy, plesiomorphy) of the traits are mentioned

or discussed there.

You may use one or more paragraphs with a “ Discussion. -” or “ Remarks. -” side-heading label

under the centered section heading for the taxonomic name. Note, however, that if the discussion

is long or wide-ranging, it may be more appropriate to create a separate Discussion section, with

a centered heading, after the taxonomic section of the manuscript. If you chose to use a separate

enlarged Discussion section later in the manuscript, it may be appropriate to use paragraph side-

headings within it, to designate information from various taxa or subjects.

Whether either discussion paragraph(s) in a taxonomic section, or a separate Discussion section

later, are used, do not list data for a particular specimen in the text. (This is because specimen

data must conform to the locality data format, which is awkward within text.) If you must refer

to a specimen using its locality, do so generally and give reference to its data citation in the Material

Examined paragraph (i.e., “. . . but the male from Redwood Creek, California [see Material Ex¬

amined] ...” It is permissible, however, to generally refer to locations in the text without evoking

the locality data format (e.g., “We collected additional specimens near Hatfield Creek, Gunnison

Co., Colorado.”).

If you comment on the etymology of the name, create a separate paragraph labeled “ Etymol¬

ogy.-” as the last in this sequence of miscellaneous paragraphs, and place it immediately before

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Yol. 69(2)

the Material Examined paragraph. Do not place gratuitous remarks in an Etymology paragraph,

put them in the Acknowledgment section at the end of the manuscript.

(7) Material Examined paragraph: ( Required terminal paragraph [reduced to 8 pt type in journal] for

section. Indented paragraph format.)

Material Examined. —(See example of Material Examined paragraph below.). This paragraph is

necessary, whether material in addition to that contained in the Types paragraph was examined

or not. If only types were examined, their data is listed under Types, and the Material Examined

paragraph should state simply “see Types.”

Other Conventions for Taxonomic Articles

Abstracts.— All new taxa or taxonomic reassignments that are mentioned in the abstract must be

followed by the appropriate new status descriptor in capital letters (i.e., NEW SPECIES, NEW GENUS,

NEW SYNONYMY, etc.)

Depository Abbreviations.— Abbreviations for specimen depositories (e.g., museums, personal col¬

lections) may be used, and are preferred for non-types. Place abbreviations for depositories (including

mention of their city) in a separate, appropriately labeled paragraph at the end of the Methods (or, in

its absence, Introduction) section. Do not incorporate depository abbreviations in the Acknowledge¬

ment section. Note that depository information (including city) must be fully written-out for holo-,

alio-, lecto-, or neotypes in the Types paragraph, but that paratype depositions noted there may use

abbreviations; mention of depositories for the types of synonyms in the synonymy listings should use

abbreviations.

Keys.— Keys are optional, but if provided, they must meet the following criteria. Keys must be

dichotomous, and have “back-tracking” notation immediately after each couplet number. Couplet

statements must be reasonably uniform, telegraphic, and comparative between opposing couplets,

where possible; statements should follow the description requirements (above). Where new taxa are

keyed out, follow their name with the appropriate new status descriptor in capital letters. Couplet

example:

2a (lb) Thorax black; wing length < 3.0 x width; labium with 4-6 sharp-tipped setae. .. R. cobblus

2b Thorax white; wing length > 3.5 x length; labium with 7-15 incrassate setae.

. R. thermophilus NEW SPECIES

Locality Data Format

All locality data associated with specimens (except types) must occur in a separate Material Examined

paragraph that ends the paragraph series for the section for a given taxonomic name; data for types

[holo-, alio-, lecto-, neo-, paratypes] must occur in the Types paragraph (see taxonomic format), but

all other material is listed in the Material Examined paragraph. In Scientific Notes involving new

records or hosts, the data paragraph, usually labeled “ Records. -,” occurs at the end of the note.

The Pan-Pacific Entomologist uses a particular, order-dependant telegraphic format for locality data

to minimize the necessary printing of geopolitical entities and information in the data block, as follows:

For all data:

(1) List country first, in all capital letters, followed by a period [.] (i.e., “USA.” or “CANADA.”).

When more than one country is listed in a given data block. List the countries in alphabetical

order in the telegraphic format, except that U.S.A. occurs first in the data block [its format is

treated differently, see (2a, 2') below]. If only U.S.A. data is present in the data block, omit

indication of the country. Mention a country only once in the telegraphic format.

For U.S.A. data (50 states only, treat non-state political associates [e.g., Guam, Virgin Islands] as

other countries):

(2a) Denote states in all capital letters, followed by a period [.] (i.e., “CALIFORNIA.”). List states

in alphabetical order, and mention a state only once in the telegraphic format.

(2b) Next denote counties (or equivalents) in all capital letters and underlined [to indicate italics],

followed by “Co.” and a colon [:] (i.e., “ SACRAMENTO Co.: ”). List counties in alphabetical

order after their state, and mention a county only once. It is the responsibility of the author to

list all counties, even if they do not occur on data labels-, consult an appropriate atlas/map. If

1993

TAXONOMIC/LOCALITY DATA FORMATS

197

the county cannot be ascertained, list the data under “ COUNTY UNKNOWN: ” at the end

of the string for the given state.

For countries other than U.S.A.:

(2') List next largest political area designation below federal level [i.e., Canadian provinces, Mexican

states, Japanese perfectures ] in all capital letters and underlined [to indicate italics], followed

by a colon [:] (i.e., “ SONORA: ” or “ ALBERTA: ”). List these geopolitical subdivisions in

alphabetical order after their country, and mention each only once. It is the responsibility of

the author to list all appropriate foreign subdivisions, even if they do not occur on data labels ;

these subdivisions can usually be found in Webster’s New Geographic Dictionary (Merriam-

Webster Publishers, Springfield, Massachusetts) or on an appropriately detailed local atlas/

map. If the subunit cannot be ascertained, list the data under “ PROVINCE [or STATE, etc.,

as appropriate] UNKNOWN: ” at the end of the string for the given country.

For all data:

(3) For that local portion of the locality data that is subordinate to the level of a U.S. county or

a major foreign gopolitical subdivision, list the local descriptor items (location, date, collector,

host, etc.) separated by commas [,], and separate information from various locations by semi¬

colons [;]. When the local data for a given county or foreign subdivision has been completed,

end in a period [.] and begin the next larger (alphabetized) division (i.e., country, state, county).

Minimize repeating redundant local locality information inasmuch as clarity can be maintained

and length can be shortened; this requires planning the data order for efficient listing. For

example, you may replace redundant descriptors with “same except,” “same loc.” or similar

notations (e.g., “. ..; 10 km S of South Lake Tahoe, hwy 50, 2 Jul 1977; same loc., 4 Aug

1983; . . .”).

(A) For the local location, use the format “5 km E of Palo Alto,” including “of,” not “5 km

E Palo Alto” [“East Palo Alto” may be a place!] All distances and elevations cited must

be in metric, even if they are not so on data label and the author must convert. If you want

to list distances in miles or elevations in feet (as “ft” not “'”), place these non-metric

measurements within parentheses immediately after their metric conversions [i.e., “5 km

(3 mi) E of Anywhere, 3050 m (10,000 ft)”]; do not include English measurements without

metrics. Omit terminating periods after abbreviations for locations or their descriptors

(e.g., hwy, mts, cyn, nr, jet); omit initial capital letters for these also, unless a direction or

proper name is involved (e.g., N, E, SW, Mt Rushmore, Haines Jet).

(B) For dates, use three Roman letter abbreviations for months, with day before month, and

entire year after month [i.e., “25 Jun 1985”].

and date. (If the host is mentioned for the first time in the article, it must have the spelled

out taxonomic author cited.) When listing an abbreviated host genus, or a person name,

retain periods after the abbreviations (e.g, P. ponderosa, F. W. Ringer).

(D) If the number of specimens, sexes or morphs, or an abbreviation of their depository is to

be included for a data label, place these last, just before the terminating semicolon (or

period) for the data.

Example of data format and Material Examined paragraph:

Material Examined. -USA. CALIFORNIA. CALAVERAS Co.: 18 km (10.8 mi) E of Arnold, 1680

m (5516 ft), 17 Sep 1977, A. H. Geptor, P. lambertiana Douglas, 1 female. SAN BERNARDINO

Co.: San Bernardino Mts, 3 km S of Jenks Lake, 2200 m, 16 Aug 1977, A. H. Geptor, P. lambertiana,

14 females; 5 km NW of Gregory, 1490 m, 17 Aug 1977, F. W. Holling, P, ponderosa Lawson, 16

females. OREGON. JACKSON Co.: 15 km S of Union Creek, hwy 62, 850 m, 5 Apr 1978, F. W.

Holling, P. lambertiana, 3 females. AUSTRALIA. AUSTRALIAN CAPITAL TERRITORY: Can¬

berra, 8 Sep 1983, D. S. Lee, 4 males. NEW SOUTH WALES: Newcastle, 8 Oct 1974, J. Cashner

(CSIRO). WESTERN AUSTRALIA: Perth, 9 Nov 1976, A. J. Rammery, 6 males; same loc., 12 Nov

1976, S. W. Rammery, 7 females. CANADA. ALBERTA: 6 km N of Edmonton, 12 Jun 1983, D.

Kinny, Picea sp. BRITISH COLUMBIA: 21 km S of 100 Mile House, hwy 97, 910 m, 13 Jul 1978,

P. contorta Douglas, J. T. Sorensen (78G125), 3 females; 40 km E of Prince George, hwy 16, 14 Jul

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 69(2)

1978, 8 females (deposited BM[NH]); 5 km N of Spuzzum, hwy 1,13 Jul 1978, P. monticola Douglas,

6 females. INDIA. MADHYA PRADESH: Mandla, 28 Jun 1988, 4 males; 3 km E of Jabalpur, 30

May 1989, P. S. Bashu; Itarsi, 2 Sep 1957, 3 females (deposited USNM). MAHARASHTRA: 2 km

S of Wardha, 6 Feb 1945, D. Waspal. ITALY. TOSCANA: Siena, 12 Jun 1966, T. Peller, 6 males, 3

females. MEXICO. CHIHUAHUA: El Carrizo, 14 Aug 1945. JALISCO: 1 km N of Tomatlan, 13

May 1979. OAXACA: Choapan, 6 Dec 1957, F. George; Tlaxiaco, 23 Sep 1966, K. Gunner. NEW

ZEALAND. CANTERBURY: Ashburton, 14 Oct 1971, D. S. Keller; 15 km W of Rangiora, 12 Dec

1956, W. W. Lessa; sameloc., 14 Jan 1978, O. P. Hue. OTAGO: Alexandra, 7 Jun 1955, F. Doncaster.

TARANAKI: Waitara, no date. PEOPLE’S REPUBLIC OF CHINA. FUJIAN: 2 km S of Nanping,

7 Oct 1956, Y.-L. Wong, 7 females, 2 males. SHANDONG: Xintai, 1 Feb 1978, W.-Y. Chu; 3 km

E of Jimo, 23 Sep 1983, W.-Y. Chu.

PAN-PACIFIC ENTOMOLOGIST

Information for Contributors

See volume 66 (1): 1-8, January 1990, for detailed general format information and the issues thereafter for examples; see below for

discussion of this journal’s specific formats for taxonomic manuscripts and locality data for specimens. Manuscripts must be in English,

but foreign language summaries are permitted. Manuscripts not meeting the format guidelines may be returned. Please maintain a copy

of the article on a word-processor because revisions are usually necessary before acceptance, pending review and copy-editing.