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BRITISH MUSEUM (NATURAL HISTORY)
INSECTS OF SAMOA
AND OTHER SAMOAN TERRESTRIAL
ARTHROPODA
PART VI OTHER ORDERS OF INSECTS
FASC. 2. Pp. 45-76
PLECFOPTERA
By R. 3 TILLYARD, Sc.D. (Cantab.), F.R.S., and J. A. LESTAGE
hea SIPHONAPTERA
hone assy, 3 By: PA. - BUXTON, M.A:
“a THYSANOPTERA
vy oN ere By: RICHARD, S. BAGNALL, -E-RS.E., F.LS.
ark coe : WITH KIGHT TEXT-FIGURES
| pEPARTMENT x
Sy OF ov
TomeLoe”
LONDON :
PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM
: SOLD AT
Tan Brrmsh Musnum (Naruran History), CROMWELL Roap, 8.W.7
AND BY
B. -QuaritcH, Ltp.; Dunav & Co., Lrp.; THE Oxrorp UNIVERSITY PRESS; AND
WHELDON & RS Me Lrp., Lonpon; abso By OntIveR & Boyp, EpInscurGH
1928
Issued 23rd June, 1928.] 4 [Price Two Shillings and Sixpence.
INSECTS OF SAMOA
AND OTHER SAMOAN TERRESTRIAL
ARTHROPODA °
Although a monograph, or series of papers, dealing comprehensively with
the land arthropod fauna of any group of islands in the South Pacific may be
expected to yield valuable results, in connection with distribution, modification
due to isolation, and other problems, no such work is at present im existence.
In order in some measure to remedy this deficiency, and in view of benefits
directly accruing to the National Collections, the Trustees of the British
Museum have undertaken the publication of an account of the Insects and other
Terrestrial Arthropoda collected in the Samoan Islands, in 1924-1925, by
Messrs. P. A. Buxton and G. H. E. Hopkins, during the Expedition of the
London School of Hygiene and Tropical Medicine to the South Pacific.
Advantage has been taken of the opportunity thus afforded, to make the studies
as complete as possible by including in them.all Samoan material of the groups
concerned in both the British Museum (Natural History) and (by courtesy of
the authorities of that institution) the Bishop Museum, Honolulu.
It is not intended that contributors to the text shall be confined to the
Museum Staff or to any one nation, but, so far as possible, the assistance of the
leading authorities on all groups to be dealt with has been obtained.
The ork will be divided into eight “Parts ’’ (see p. 3 of wrapper), which
will be subdivided into “Fascicles.”” Each of the latter, which will appear as —
ready in any order, will consist of one or more contributions. On the
completion of the work it is intended to issue a general survey, summarising
the whole and drawing from it such conclusions as may be warranted.
A list of Fascicles already issued will be found on the back of this wrapper.
E. E. AUSTEN, —
Keeper of Entomology.
British Museum (Naturat History),
CromweLt Roap, 5.W.7.
INSECTS OF SAMOA
PART \VesWAses 2
PLECTOPTERA (MAYFLIES)
By R. J. Tittyarp, Sc.D. (Cantas.), F.R.S., Chief Entomologist, Common-
wealth Council for Scientific and Industrial Research
(With 2 Text-figures.)
THE material collected in this Order consists only of three specimens belonging
to a single species of Cloeon, viz. a male imago, a female imago and a male sub-
imago. These are all dried specimens, pinned, and with the wings considerably
damaged. Such material is not very satisfactory for description in this Order,
especially in the case of small, delicate insects like the Baétidae, which need to
be preserved carefully in alcohol. The right forewing of the female imago is the
only wing sufficiently well preserved to give the complete venation; this is
shown in Text-fig. 1. In order to describe the genitalia, the dry and rather
shrivelled end-segments of the abdomens of both male and female imagines
were cut off and macerated in 10 per cent. caustic potash ; the very brittle cerci
were already badly damaged.
The colours in the living insects of this genus are often very different from
those of the dried specimens. No notes were taken of the colours in life, so that
it is only possible to state the colouring after death.
BAETIDAE.
1. Cloéon samoénse, sp. n. (Text-figs. 1, 2).
36 Imago :-—
Forewing 4:5 mm.
General body colouring dark chocolate brown ; cerci pale semi-transparent
brownish ; wings hyaline with blackish veins.
Yams 23 45 1
46 INSECTS OF SAMOA.
Head with enormous divided eyes, black, the turban-eyes (collapsed) on
broad bases; antennae with very short, broad scape, slender pedicel, and
slender, delicate, indistinctly segmented flagellum.
Thorax dark brown without any definite pattern ; legs brownish, but with
the fore femora paler, mostly straw-coloured, the same colour being most
TEext-FIG. 1.—Cloéon samoénse, sp. n., allotype 9, forewing. Length 5-7 mm. New Nota-
tion, the prefix I indicating interpolated veins; MA anterior or convex portion of media ;
M posterior or concave portion of same.
prominent around the under side of the knee-joint and extending along the basal
portion of the tibia also; claws of the fore tarsus very strongly dissimilar, the
outer narrow, sharply pointed, the inner broad, subtriangular, with its exterior
edge straight, its interior edge long, sub-crenulate, extending to below the middle
of the outer claw.
Wings.—¥orewing (somewhat crumpled) hyaline with blackish venation
except only C, Sc and R,, which are more brownish. Venation much as in the
female (Text-fig. 1), but pterostigmatic region broader, with only two cross-
veins between C and Sc and a single one between Sc and R,;. Hind wings absent.
Abdomen dark brown, the basal and distal margins of the segments ringed
with black. Tenth tergite well-developed, overlapping base of appendix
dorsalis. Forceps-basis short, rather broad; forceps (style) two-segmented,
the basal segment fully as long as the ninth abdominal segment, somewhat
swollen basally and clubbed distally; the distal segment a minute, ovoid
PLECTOPTERA. 47
appendage attached to the club of the basal segment; penis very short, its
lobes upcurved and slightly angulated in lateral view. (Text-fig. 2.) Cerci
(broken in case of type) evidently
very slender, with all but a few
basal segments elongate.
3g subvmago.—Difters from the
imago in having the wings lightly
infuscated and the legs straw-
coloured, as well as in the usual
differences of the less developed
eyes, cerci and forceps.
- 2 vmago.—Considerably larger
than 3; forewing 5-7 mm. General
TEXtT-FIG. 2.—Cloeén samoénse, sp. n., holotype
colour yellowish brown, with eyes 3, lateral view of genitalia. 9, 10, seg-
blackish - antennae with distal ments ; fb, forceps basis; f1, fo, the two seg-
f ‘ ments of the forceps; p, penis. (Appendix
end of pedicel and whole of dorsalis and cerci broken off.)
flagellum blackish ; legs with tarsi
blackish. Forewing (Text-fig. 1) hyaline, with strong brownish coloration of
the whole of the costal and subcostal areas; pterostigmatic area with three
cross-veins between C and Sc, and three between Sc and R,. Abdomen with
ninth sternite forming a well-developed ventral plate, apparently shghtly
angulated at each side and with a projecting median portion, evenly rounded
off (cerci damaged in case of type).
The venational notation used in Text-fig. 1 is the New Notation as given in
my Insects of Australia and New Zealand, p. 59 (Table), 1926.
Types and Localities :—
3 mago, holotype, Upolu, Vailima, 25.x.1924.
2 mago, allotype, Upolu, Apia, 13.x.1925.
3 subumago, paratype, Upolu, Malololelei, 2,000 ft., xi1.1925.
LIST OF TEXT-FIGURES.
Text-fig. 1. Cloéon samoénse, sp. n., allotype 9, forewing. Length 5-7 mm. New Notation,
the prefix I indicating interpolated veins; MA, anterior or convex portion of
media ; M, posterior or concave portion of same.
,, 2. Cloéon samoénse, sp. n., holotype g, lateral view of genitalia. 9, 10, segments ;
fb, forceps basis; f;, fo, the two segments of the forceps; p, penis. (Appendix
dorsalis and cerci broken off.)
48 INSECTS OF SAMOA.
REMARQUES SUR LE CLOBON SAMOENSE TILL. ET SES AFFINITES AVEC
LES AUTRES ESPECES DE LA REGION INDO-MALAISE ET
AUSTRALIENNE.
Par J. A. Lesrace, Directeur de l’Aquarium et du Musée de Pisciculture
(Bruxelles)
L’HONORABLE Mr. P. A. Buxton, a la demande de mon excellent ami Tillyard,
m’ a prié de donner mon avis sur la nouvelle espéce cloéonienne qu 1l a découverte
dans Vile Upolu.
La présence des Cloeon dans ces parages n’a rien qui puisse nous étonner,
au contraire. Sil est un genre ubiquiste, c’est bien celui-la, et je note, pour
rappel, qu'un de ses représentants, C. dipterum, a essaimé jusque dans la zone
néarctique.
Cloeon posséde une larve qui s’accommode de toutes les eaux ; on la ren-
contre méme souvent, et elle y vit fort bien, dans les cuves et les tonneaux
destinés & recevoir l’eau servant a Varrosage des jardins ; un milieu méme salin
ou saprophyte nentrave en rien son cycle évolutif. Une telle facilité d’accom-
modation a permis aux Cloeon d’avoir une géonémie particuliérement étendue,
de pouvoir prospérer et se perpétuer, beaucoup mieux que d'autres genres, la
ou ils existaient aux temps ot des continents dressaient leur masse, et ou,
aujourd’hui, des tiles en sont les seuls témoins.
Sil est relativement facile de suivre, pour certains groupes, leur évolution
dans la Notogée, c’est chose beaucoup plus ardue de le vouloir tenter quand il
s agit de formes dépendantes du domaine potamique et, surtout, de celles dont
les premiers stades se passent dans un milieu tout différent de celui du stade
parfait. Si Pon admet la classification actuelle de la Notogée—régions papou-
asienne, australienne, polynésienne, néo-zélandaise, hawaienne—on peut se
demander a quelle souche se rattachent les Cloeon de Samoa.
Ce groupe de Plectoptéres offre, en effet, une uniformité telle, que, en
principe, le critére chromatique est le seul qui soit mis en valeur. Ailleurs, la
morphologie de Pandroméere offre d’excellents caractéres par son polymorphisme ;
ici, elle est on ne peut plus simple, et les genitalia ne montrent méme que rare-
ment un rudiment de pénis.
La taille ne saurait fournir un argument pour la théorie de linsularisme,
puisque des Clocon continentaux sont aussi petits, et méme davantage, que celui
dUpolu. La coloration? On ne peut en tirer partie que comme caractére
PLECTOPTERA. 49
secondaire. Les ailes? Ce sont des organes généralisés, et rien, dans la ner-
vation, ne peut nous aider.
Il est vrai que ce que nous connaissons de la faune des Ephéméropteres en
général, et, a fortiori, de celle du Royaume Pacifique, est si peu de chose que
ce serait fatuité de ma part d’élucider définitivement le probléme de l’origine de
la faune plectoptérienne de cette région.
Si nous examinons la géonémie des quelques espéces signalées dans la région
indo-malaise, la plus voisine de celle de Samoa, nous voyons que :
(a) Cloecon bimaculatum Etn. existe en Chine, au Tonkin, au Bengale, a
Java, a Sumatra, a Ceylan.
(6) Cloeon fluviatile Ulm. est, jusqu’a présent, une forme endémique de la
Nouvelle Guinée.
(c) Cloeon marginale Hag. se trouve au Tonkin, au Bengale, a Formose, a
Java, a Sumatra, a Simalur, a Ceylan, aux Philippines.
(d) Cloeon pulchellum Bks. est confiné au Bengale (Chapra).
(e) Cloeon exiguum Nav. et C. rubellum Nav. wexisteraient qu’aux
Philippines.
(f) Cloeon variegatum Chopra a été décrit des Indes anglaises (Barkuda).
(g) Cloeon virens Klp. a été trouvé a Java et a Sumatra, puis en Australie
(Kimberley).
Les données fournies par ce tableau de la répartition des Cloeon semblen
assez suggestives. Si certaines espéces sont confinées dans une seule sous-région
de la province orientale de lArctogée, d’autres, en revanche, habitent toutes
les sous-régions de la dite province et méme une partie de la région notogéenne
australienne.
Ceci prouve que l’endémisme de certaines espéces pourrait bien n’étre que
provisoire,—on connait tant de cas déja!—n’ayant d’autre base que notre
méconnaissance du groupe en question, et sa défaveur chez les explorateurs
incompétents ou trop pressés. Le peuplement sest certainement fait de l'Ouest
a PHst, si l'on se rappelle que le semis des iles malaises faisait encore partie a
une date relativement récente—la fin du Pliocéne, du Continent Indo-chinois.
La présence d'une espéce simultanément indo-malaise et australienne (Cloeon
virens Klp.) prouve, une fois de plus, les connexions de la province indo-malaise
avec |’ Australie, régions séparées actuellement par la ligne de Weber qui isole,
dune part, les Philippines, Bornéo, Célébes, les iles de la Sonde jusqw’ a Timor
50 INSECTS OF SAMOA.
(facies faunique indien prédominant) et, d’autre part, les Moluques, Kei, Aru,
Tenimber, la Nouvelle Guinée (facies faunique australien).
I] est & remarquer que, chez les formes cloéoniennes indo-malaises, et aussi
chez C. samoense, il y a, plus souvent, coloration des ailes dans les champs costal
et sous-costal ; cependant, ce n’est la qu’un caractére sexuel et, s'il est moins
accusé, on le retrouve chez les formes paléarctiques, néotropiques et éthiopiennes.
Ulmer * a remarqué que les articles des pattes des Cloeon, surtout ceux des
pattes antérieures, chez les formes indo-malaises, offraient une longueur pro-
portionnelle autre que chez les autres espéces ; les J ont, aux pattes antérieures,
les tibias doubles des fémurs, les tarses subégaux aux tibias, et, aux pattes
postérieures, les tibias 1} plus longs que les fémurs, les tarses environ les } des
tibias.T
I] serait intéressant de savoir si ce caractére est spécial aux formes de la
région indo-malaise, ou s'il existe chez des espéces connues d’ailleurs, tant
insulaires que continentales.| Comme ce caractére est généralement négligé
dans les diagnoses, on ne peut pas y attacher une valeur intrinséque, mais il est
bon de rappeler l’observation d’Ulmer pour les recherches futures.
Tillyard n’en parlant pas dans sa description du C. samoense, j'ai examiné
les exemplaires originaux que Mr. Buxton m’a soumis avec l’autorisation de
Pauteur.
La longueur proportionnelle des articles des pattes du ¢ est précisément
celle qui a été signalée pour le bloc cloéonien indo-malais: pattes I a fémurs
environ moitié plus courts que les tibias, & tibias subégaux aux tarses; ces
derniers ont la formule 2.3.4.5.1; 1 est minuscule ; 2, plus long que 3 mais plus
court que 3+4; 4, plus long que 5; pattes III a fémurs } plus courts que les
tibias, a tarses environ 4 de la longueur des tibias.
La formule tarsale 3 apparente C. samoense & C. marginale, et les deux
femelles ont un systéme de coloration identique aux ailes. Le Cloéon samoanien
g a, cependant, un caractére trés spécial ; alors que tous les autres ont l’abdomen
plus ou moins transparent, il offre une tonalité absolument uniforme, telle
que nous la montrent les femelles et, sous ce rapport, il constitue un type
particulier.
* Ulmer, Treubia, vi, p. 65, 1924.
+ La longueur des articles des tarses peut étre également variable. Je laisse de cété
ces caracteres secondaires.
ft De Paveu d’Ulmer, ce caractére se retrouve chez Cloéon africanum Uln.
PLECTOPTERA. BI
Les 2 des C. samoense et C. marginale sont a ce pot semblables qu’un
examen minutieux est nécessaire, surtout chez les exemplaires conservés in sicco.
Les dessins qui caractérisent les segments abdominaux du 3 de C. marginale
s’estompent souvent chez la 2 au point de disparaitre sous la coloration fonciére
qui passe au brun foncé (jaune d’ocre pale chez les 2 conservées en alcool) ;
cependant, a y bien regarder, on apergoit toujours des traces de Pornementation
originale des tergites visible sous une tonalité plus rougedtre que le fond; ce
nest pas le cas chez la 2 de C. samoense, dont les segments abdominaux sont de
loin aussi foncés que ceux de la 2 de C. marginale. On ne saurait, non plus,
confondre les 2 de C. samoense et de C. virens ; la coloration alaire est trés
différente.
Il y a lieu, encore, de mentionner les variantes que présente la nervation
secondaire des ailes du 3, variantes plus importantes que celles signalées dans
la diagnose originale.
Si on se reporte a Vaile de la 2 (Fig. 1 de Tillyard), il y a lieu de remarquer
que: deux nervules seulement existent dans le PT; wne seule entre SC et R,
située plus distalement que la derniére du PT ; quatre entre R, et R, : la premiére
un peu plus basale que celle formant le commencement de la corde transversale
sous-jacente,* les 2'° et 3™° comme chez la 9, la 4° dans l’espace compris
entre la 3° et ’apex ; la nervule de la 9 entre Ry et IR» n’existe pas chez le
6; iln’y a quune seule nervule entre Rsb et IR3b; une nervule existe entre
M, .» et IM et wne autre entre IM et M;..,, toutes les deux naissant a la naissance
de IM+; wne nervule relie M,.. a CU, apres leur naissance.
Evidemment, on ne saurait déclarer que cette aile et sa nervation sont car-
actéristiques pour le g; il faudrait un matériel plus riche pour décider de
Puniformité ou du polymorphisme de la nervation, méme aux deux ailes d’un
méme individu, car on sait que ce n’est pas un cas exceptionnel.
* Kile existe aussi chez la 9 comme je viens de le constater.
+ Elles sont présentes aussi chez la 9.
vay
SIPHONAPTERA
By P. A. Buxton, M.A., London School of Hygiene and Tropical Medicine.
THE fleas obtained by us were collected from man, domestic animals and rats.
None were taken on the rather numerous land birds which we collected, but it
is possible that interesting fleas might be found if search were made in the nests
of sea-birds (Sula, Phaeton, etc.). Of the three species collected, two at least
have recently been introduced.
The following species were met with, at Apia, in 1924 and 1925.
1. Pulex irritans Linn.
On one occasion great numbers were brought to us from a house which had
been shut for some months; but in general this insect was not common. P.
writans was also taken by Hopkins at Nukualofa, Tonga, in 1925, and by myself
on Tanna, New Hebrides, in September, 1925. It is almost certain that human
fleas were brought into the Pacific Islands by European shipping. Gull (Jottings
from the Pacific, 1885) states definitely that they were absent from the islands of
the Cook Group, and the atolls which lie to the north, until about 1820.
2. Xenopsylla cheopis Roths.
This insect was recorded by Doane in 1913 as occurring in Samoa. There
is no doubt at all that it has recently been introduced by European shipping.
We took specimens on Mus rattus, M. decumanus, and M. exulans ; the number
of fleas per rat was always low. Mus exulans is a small rat, found in practically
all parts of Polynesia and Melanesia; it is believed that it was carried from
island to island by canoes. We believe that it has no flea peculiar to it ; in the
Hawaiian islands, and in the New Hebrides, specimens of this rat have been
searched and no fleas found upon them. (See Buxton and Hopkins, Researches
in Polynesia and Melanesia, No. 1, Memoir Series, Lond. School Hyg. and Trop.
Med., 1927.)
53
54 INSECTS OF SAMOA.
3. Ctenocephalus felis Bouché.
This insect was not uncommon on dogs and cats in Apia; it was also
taken in Tonga and in the New Hebrides in 1925. It may be a recent intro-
duction, but it is quite possible that it was brought to the islands many centuries
ago; it is known that the Samoans, and most other Polynesians, kept domestic
dogs before the arrival of Europeans.
THYSANOPTERA
ON SOME SAMOAN AND TONGAN THYSANOPTERA, WITH SPECIAL REFER-
ENCE TO FICUS GALL-CAUSERS AND THEIR INQUILINES.
By Ricuarp 8. Baenatt, F.R.S.E., F.L.S.
(With 6 Text-figures.)
I. INTRODUCTION.
THE material described hereafter was collected and submitted to me by Messrs.
P. A. Buxton and G. H. E. Hopkins, to whom I am indebted for the oppor-
tunity of examining a collection of more than usual interest. ;
It will be noticed that with one exception the species are either leaf-gall-
causers on Ficus or inquilines thereof, and that the gall is a typical rolled leat
such as is caused by known Ficus-thrips. The exception is Rhaebothrips major,
sp. n., the second described species of a genus represented by R. latiwentris
Karny, of Formosa and Australia.
In regard to the others, none are referable to the species already known
from leaf galls on Ficus. Seven species are described, referable to three genera,
one of which is new, whilst the Ficus-Gynaikothrips, as restricted herein, would
appear to be generically distinct from other members of the genus.
Il. Ficus GALL-THRIPS OF SAMOA AND TONGA, AND THEIR ALLIES.
The genus Gynaikothrips of Zimmermann is represented by two species,
one found in Samoa, the other in Tonga. These species are the gall-causers
proper and the others undoubtedly inquilines. The recently described Adza-
phorothrips ficus Faure, of South Africa, is referred to the same genus.
All cause leaf-rolling or leaf-curling in the leaves of various species of
Ficus.
The new genus Dimorphothrips is represented by two species, inquilines in
Ficus-galls, both found in Tonga, whilst Karny’s Chelaeothrips idoliceps recently
described from a Ficus leaf-roll gall from Fiji is referred to the genus.
55
56 INSECTS OF SAMOA.
Three species, one found in Samoa and two in Tonga, belong to the genus
Huoplothrips and are without doubt inquilines. The genus was erected by
Hood in 1918 for #. bagnalli Hood, a North Queensland species represented by
a single example collected by Mr. A. A. Girault by sweeping ; later van Leeuwen
and Karny recorded it as a gall inhabitant from leaf galls on Randa chartacea
and Snulax australis in New South Wales.
It is possible that more than one species is represented in these Australian
records, and therefore—until more material is forthcoming—I have only
attempted to diagnose the three species herein described, which in themselves
present a difficult. problem.
IUl. Oruer Ficus GALL-THRIPS.
In the following notes I do not pretend to cover all that is known of Ficus
gall-thrips and their inquilines.
In his * Beitrige zur Kenntnis der Gallen von Java” (Zettschr. fiir wissen-
schaftliche Insektenbiologie, 1914-1916) Karny and van Leeuwen-Reijnvaan
enumerate the following Thysanoptera, all of which belong to the Tubulifera,
from Ficus leaf-galls :
1. Haplothrips (inquilinus Pr. 1921). 6. Gynarkothrips longicornis K.
2. Androthrips melastomae (Zimm.). 7 5 enquilinus K.
3. Mesothrips jordan Zimm. 8. 53 mutans K.
4, ‘. parous K. 9. Gigantothrips elegans Zimm.
5. Gynatkothrips uzelv Zimm. 10. Leptothrips constrictus Kk.
Of these, Gynaikothrips uzeli and Gigantothrips elegans are true gall-causers
of wide distribution; Gynatkothrips imitans and G. inquilinus are described
from Ficus cuspidata Reimw. and Ficus sp. respectively, whilst Mesothrips
parvus and Gynaikothrips longicornis are from F. punctata Thunb. only. The
others are found on several species of Ficus, whilst Haplothrips inquilinus,
Androthrips melastomae, Mesothrips jordani and Leptothrips constrictus are also
recorded from plants other than Ficus.
In 1923 (Journ. Stam Society, xvi, pt. 2) Karny recorded Gynaikothrips
longiceps K. from Ficus benjamina. The record rests on a solitary example,
and the author expresses some doubt as to its identification. In the same
paper Karny suggests that his Leptothrips constrictus may prove to be a micro-
merous form of Mesothrips jordani, and that so-called Androthrips melastomae
THYSANOPTERA. 57
from different host-plants may each prove to be different species, as is very likely
to be the case.
In 1925 Karny (Bull. Ent. Res., vol. xvi, p. 125) described a new sub-species
of Gynatkothrips uzeli together with a single example of Liothrips postocularis,
sp. n.; specimens were found in the curled margins of leaves of Ficus, sp. from
Hast Africa. He also described his Fijian Chelaeothrips «doliceps referred to
above, and here assigned to the new genus Dimorphothrips.
In the same year Faure described his Adiaphorothrips ficus, of South Africa,
which belongs to the genus Gynatkothrips, whilst Watson (Synopsis and Catalog
of the Thysanoptera of North America, 1923) described Sedulothrips hubbella from
Ficus, sp.
From these remarks it will be seen that the material from Samoa and
Tonga, in so largely adding to our knowledge of the subject, is of considerable
interest and importance.
IV. GEOGRAPHICAL DISTRIBUTION.
The following list of the known species of the four genera represented in
this collection, with their distribution, is informative.
Genus Gynaikothrips Zimm.
Species causing leaf-galls on Ficus, spp.
G. hystrix Bagn. ‘Tonga.
G. hopkinst Bagn. Samoa.
G. australis Bagn. Australia (N.S.W.).
G. ficus (Faure). South Africa.
G. uzelt Zimm. Indo-Malaya, N. America, Mediterranean,
Canaries, etc.
Note——The last-named species requires study, as do also G. longicornis,
G. inqulinus and G. imitans, which probably fall into this genus as here
restricted.
Genus Dimorphothrips Bagn.
Inhabitants of Ficus leaf-galls.
D. microchaetus Bagn. Tonga.
D. solitus Bagn. Tonga.
D. adoliceps (K.). Fiji.
58 INSECTS OF SAMOA.
Genus Rhaebothrips Karny.
R. latwentris K. f. aptera. Formosa.
ft. ‘s f. macroptera. Australia.
R. major Bagn. Samoa.
Genus Huoplothrips Hood.
Inhabitants of leaf-galls.
E. bagnalla Hood. N. Australia.
E. buxton: Bagn. Tonga.
EH. mcognitus Bagn. Tonga.
E. uncinatus Bagn. Samoa.
Thus, with the exception of Dimorphothrips, which is purely Pacific in its
distribution, all the genera are represented in Australia, but although the Indo-
Malayan fig-thrips are well known, only the genus Gynatkothrips is represented
in Indo-Malaya proper.
V. TERATOLOGY AND AN ESTABLISHED SPECIFIC CHARACTER.
In my Memoir on the Thysanoptera of the Seychelles (Ann. Mag. Nat.
Hist. (9), vil, pp. 257-293, 1921) I noted a teratological condition in the pronotal
chaetotaxy of an Idolothripid (Dicaiothrips hystrix Bagn.), wherein the outer
postero-mareginal bristle is duplicated, the inner bristle replacing the usual
micro-setae. The same condition exists in Gynaikothrips hystrix described
herein, and is actually fixed and of specific value.
VI. DESCRIPTION OF THE GALLS.
Both edges of the leaf are curled upwards and inwards in an unbroken roll
towards the midrib (accompanied by a more or less strong curvature), thus
forming two long tubes in which the insects are to be found.
VII. Descriprions oF FICUS-AFFECTING GENERA AND SPECIES.
Genus Dimorphothrips, nov.
3. Head long, more than 1-5 times as long as broad with cheeks, which
are 2-0 times as long as the eyes and evenly arcuate ; vertex conically produced,
bearing the anterior ocellus forwardly directed at the apex; posterior ocelli
well forward, but below a line drawn across the anterior margin of the eyes ;
equidistant or having the anterior ocellus slightly more apart from the posterior
THYSANOPTERA. 59
ocelli (in D. idoliceps). Post-ocular and post-ocellar setae minute. Mouth-
cone short and bluntly rounded. Antenna about 1-3 times as long as the head,
somewhat stout ; first joint large, elongate and cylindrical, intermediate joints
clavate and the last two joints broadly united.
Pronotum transverse, decidedly shorter than the head; bristle at each
posterior angle stout, prominent; the inner postero-angular pair short and
all other pronotal setae minute. Fore-legs stout, the tibia only 2-0 times as
long as broad at apex, fore-tarsus large, with a large stout tooth; hind and
intermediate legs longer and somewhat stout. Wings heavy, not constricted
near middle, fore-wings with a long series of duplicated cilia. Abdomen some-
what elongated, narrower than the pterothorax; segments, more noticeably
the intermediate ones, laterally spinose. Bristles at posterior angles of seg-
ments short and spine-like as in Gigantothrips, but with segment 9 either similarly
short and spine-like in one species or with the normal long bristles in another,
or in yet another species with long abnormally stout bristles. In the first and
the last the tube is shghtly shorter than the head, whilst in the latter—the
species with the normal long bristles on the ninth segment—it is decidedly
longer than the head. The tube provides a character that may be generic in
that, of the longer terminal hairs the one on each side of the minute central
setae is distinctly shorter than the others. ;
The genus is peculiar in the form of the head, the short broad fore-tibiae,
the chaetotaxy of the pronotum, the chaetotaxy of the abdomen, including
the spinose sides of the segments, and especially the dimorphism exhibited in
the chaetotaxy of the ninth abdominal segment which suggests the generic name.
The characteristic terminal hairs of the tube described above would also appear
to be distinctive.
From Gigantothrips the genus may be distinguished by the form of head,
the stout fore-tibiae and the heavily armed fore-tarsus, and the stout antennae.
It resembles Coryphothrips in some respects, such as in the conical production
of the head and the chaetotaxy of the hind margin of the pronotum, but in
that genus the antennae are set well below the vertex, the anterior ocellus is
situated below the conical production, the antennae are long and slender, the
fore-legs normally long, not stout, and the tarsi unarmed; the chaetotaxy of
the abdomen is normal, whilst the fore-wings are devoid of duplicated cilia.
Karny’s Chelaeothrips cdoliceps is referable to this genus.
The specimens described below are in both cases almost certainly $3; in
60 INSECTS OF SAMOA.
D. solitus there is no doubt whatever as regards the sex, but in D. microchaetus
it is impossible to examine the structure of the base of the tube. In my opinion,
however, the inner spine at each posterior angle of abdominal segment 9 repre-
sents the pair that is peculiar to the 3, whilst the specimens of D. idoliceps (K.)
that I have had the opportunity of examining also appear to be males.
Genotype Dimorphothrips microchaetus.
TABLE OF SPECIES.
1. Antennal joints 3-8 yellow ; conical production of head longer ;
tube shorter than head; bristles of 9th abdominal segment
long, abnormally stout. Hab. Fiji : ! :
Antennal coloration otherwise; conical production of head
shorter; chaetotaxy of 9th abdominal segment otherwise.
Hab. Tonga : ; : : : : : é
. Size larger, c.3-Omm. Tube longer, 1-4 times as long as the head
and having the terminal hairs 0-5 the length of the tube.
Bristles of 9th abdominal segment reduced as in the preceding
segments, and only about 0-12 as long as the tube . : . D. microchaetus, sp. n.
Size smaller, c. 2-4: mm. Tube shorter, 0-9 the length of the head
with the terminal hairs 0-7 the length of the tube. Bristles of
9th abdominal segment normal, the outer pair being about 0-9
the length of the tube . : : : : : : . _ D. solitus, sp. n.
D. idoliceps (Karny, 1925).
bo
bo
1. Dimorphothrips microchaetus, sp. n. (Text-fig. 1).
g. Length c. 3-0 mm.
With the characters of the genus.
Dark chestnut brown, fore tibiae and all tarsi yellow shaded with light
erey-brown ; antennal joint 1 concolorous with head, 2 brown, yellowish-brown
apically ; 7 and 8 brown with base of 7 inclined to be somewhat paler ; 3 yellow,
4 a deeper yellow with apical part (about 0-4) shaded with pale grey-brown,
5 similar, but with apical half of a deeper brown shade and 6 brownish-yellow,
with apical half darkish brown. Wings brown and cilia fumate.
Head not quite 0-6 as broad as long, and 1-6 times as long as the pronotum.
Antenna with joint 1 unusually long, joints 3-5 clavate, with the relative lengths
(and breadths) of segments approximately as follows: 54(46); 54(43); 81(41) ;
78(46) ; 78(45); 68(42); 56(32); 32(18) pw.
Pronotum about 1:7 times as broad near base as long; outer postero-
marginal (postero-angular) bristle stout, 98 « long or nearly 0-5 the median
THYSANOPTERA. 61
length of pronotum, and inner pair apparently about 0-5 the length of the outer.
Fore-coxal seta only about 40 in length. Fore-
wings with 21 duplicated cilia. Sides of abdominal
segments 3-6 very noticeably spinose; bristles on
posterior angles of abdominal segments 50 to 68 » in
length, the outer pair on segment 9 being 63 » long
and longer than the adjacent spine characteristic of
the g. Tube 1-4 times the length of the head, with
the terminal hairs 0:5 the length of the tube, except
the inmost pair, which are a little more than 0-5 as
long as the others.
Length (and breadth) of head, pronotum and
pterothorax 360(205); 210(350); and 525(472) yp
respectively ; length of femora and tibiae I, 283(156) ;
162(80) ; IL, 256(108) ; 216(75); and III, 338(128) ;
297(95) w. Length of tube 500, breadth at base 104
and at apex 47 p.
This species is sharply distinguished from the
following by its larger size, the very long tube, and Te een, rete
3 2 microchaetus, sp. n. Pos-
the absence of long bristles on the 9th abdominal terior abdominal segments
segment. and tube.
Tonga: Nukualofa, 1 3, 20.11.1925, in galls of Gynatkothrips hopkinsi on
Ficus leaves.
2. Dimorphothrips solitus, sp. n. (Text-fig. 2.)
¢. Length about 2-4 mm.
Colour and general form as in D. microchaetus.
Pronotum 1-6 times as broad as long, bristle at hind angle 108 » long, or
a little more than 0-5 the length of the pronotum, and the inner only 32 » or
about 0-3 the length of the outer. Fore-coxal seta 32 » long. Fore-wings with
21 duplicated cilia as in D. microchaetus.
Abdomen with sides of segments 3-7 most noticeably spinose, bristles at
posterior angles somewhat longer than in microchaetus c. 60-80 , and those on
segment 9 normal, the outer pair being nearly 0-9 the length of the tube, with
the inner adjacent spine (characteristic of the §) apparently slightly longer
and stouter than in D. microchaetus. Tube 0-9 the length of the head, with the
vil. 2 2
62 INSECTS OF SAMOA.
terminal bristles 0:7 its length, except the inmost pair, which are 0:5 as long
as the others.
The lengths (and breadths) of the antennal segments 3-8 are approximately
as follows : 73(35) ; 73(40) ; 70(38); 60(35); 52(30) ; 32(16) p.
Length (and breadth) of head, pronotum and pterothorax 337(190) :
202(324) and 460(418) » respectively ; length (and breadth) of femora and
Text-FiG. 2.—Dimorphothrips solitus, sp. n. A, head and thorax; B, fore-leg; C, posterior
abdominal segments and tube ; D, antenna.
tibiae, I, 270(142); 148(68); II, c. 200(74); 190(62); and III, 310(100) ;
270(68) ». Length of tube 310, breadth at base 81 and at apex 40 yp.
Tonga: Nukualofa, 1 3, 20.11.1925, in galls of Gynaikothrips hopkinsi on
Ficus leaves.
Genus Gynaikothrips Zimmermann, s. str.
Head longer than broad, and longer than the pronotum ; vertex conically
produced, bearing the anterior ocellus at apex ; constricted behind eyes, where
the cheek is inclined to be dentiform before constriction ; mouth-cone reaching
THYSANOPTERA. 63
only about 0-5 across prosternum, bluntly rounded ; antenna 8-jointed, normal.
Two pairs of postocular bristles, and a pair of bristles immediately behind the
posterior ocelli ; cheeks either entirely spinulose, or with a few scattered setae.
Pronotal bristles well-developed, outer postero-angular with a subsidiary
bristle either much smaller or (as in G. hystrix) subequal in length.
Fore-wings broad, not constricted near middle and with a series of dupli-
cated cilia. Legs normal, fore-tarsus with a small tooth in the Q and a longer,
stronger one in the 3.
Tube long, either a little shorter, or a little longer, than the head.
Species cause leaf-curling and rolling on Ficus spp.
Since Gynatkothrips uzeli is the genotype, its name must stand, and it will
be necessary to remove to another genus (or to other genera) most of the species
described by Karny.
This section of the genus is characterised by the two pairs of postocular
bristles and the spinulose cheeks. The chaetotaxy reaches its maximum in
G. hystrix, 1 which the outer postero-marginal (postero-angular) pronotal
bristle is duplicated, so that a condition that I have described as teratological
in a Seychelles insect (Decaiothrips hystrix Bagn.) is actually fixed, and of specific
importance, in Gynarkothrips hystrix.
Faure’s Adiaphorothrips ficus, of South Africa, belongs to this genus.
TABLE OF SPECIES.
The following table deals only with the species herein discussed ; the smaller G. wzeli is already
well-known, and the three fig-species, G. longicornis, G. inquilinus and G. imitans K., will almost
certainly be found to fall into the section.
1. Antenna stouter, third joint 2-0 to 2°5 times as long as broad, with
joints 3-8 pale; post-oculars long, 1:2 to 1-6 times as long as
eye; tube nearly as long as head . : 2.
Antenna more slender, 1-6 times as long as Tex chad Sasa
2°8 to 3-2 times as long as broad, with most of joint 3 and
basal halves of 4-6 pale yellow; post-oculars minute. Cheeks
and outer margins of fore-femora evenly and minutely spinulose.
Tube 0:94 of length of head, with terminal hairs about 0-5 as
long as tube. Hab. South Africa j . G. ficus (Faure).
. Cheeks with angulation at constriction Before eye weak, genal
setae many, scattered, long (up to 45 win length). Post-ocular
bristles somewhat, and post-ocellars distinctly, longer. Pro-
notal bristles longer, postero-angular bristle duplicated by
abnormal development of adjacent inner microseta, which is
subequal in length. Fore-coxal seta long, 90 to 100 w. Outer
margins of femora closely and strongly setose, longest setae in
64 INSECTS OF SAMOA.
fore-femora c. 120 w in length. Abdominal bristles and
terminal hairs longer. Hab. Tonga. . . Gi hystraz,'sp n.-
Cheeks with angulation at constriction before a rinekodly, denti-
form; almost entirely devoid of genal setae except two short
pairs (18 to 24 uw long) behind constriction. Post-ocular bristles
somewhat, and post-ocellars distinctly, shorter. Pronotal
bristles not so long, inner micro-seta adjacent to postero-angular
usually normally small, rarely developed, and at its maximum
0-7 of length of that bristle. Fore-coxal seta shorter, c. 40 wu
long. Outer margin of fore-femur with only two pairs of
prominent bristles, near middle and before apex, the former
the longer, c. 70 win length. Abdominal bristles and terminal
hairs not so long. Hab. Samoa . : 2 . “ . G. hopkinsi, sp. n.
3. Gynaikothrips hystrix, sp. n. (Text-fig. 3).
9. Length 2-9 to 3-2 mm.
Colour dark chestnut-brown, fore-tibia and tarsus yellow, shaded with
brown, intermediate and hind tarsi yellowish-brown. Antenna with joint 1
concolorous with head, 2 lighter brown and paler distally, 3 pale yellow, 4 and
5 also pale yellow, but somewhat deeper in colour distally, 6 yellow, lightly
shaded with brown in distal half, and 7 and 8 yellowish-brown.
(The above description of colour applies to a fully coloured individual, but
most of those before me have the body colour much lighter, due, I think, to
the medium in which they were collected.)
Head not quite 1-5 times as long as broad; angle at constriction of head
behind eyes not strong. Postoculars long, 190 to 220 uw, inner pair on a line
with inner margins of eyes, separated by about 81 » and on a higher plane than
the outer pair, which are separated by 190 » ; post-ocellar pair also long (120 2),
nearly reaching to the apex of the first antennal joint. Genal setae scattered,
long, the longer (near the eyes) up to 45 w in length. Antenna 1-8 times as
long as the head, with joint 1 rather long, 3 to 6 claviform, and 7 and 8 closely
united. Relative lengths (and breadths) of antennal joints approximately as
follows: 68(52); 60(46); 110(42); 100(49); 100(47); 84(42); 72(33); 46(20) »
Pronotum transverse, all bristles present and abnormally long, the one
postero-marginal (or angular) bristle duplicated by the abnormal development
of the usual inner micro-setae, so that there are 2 subequal outer bristles situated
close together in addition to an inner pair. Outer postero-marginal pairs
(c. 240 ») longer than the median length of pronotum, and than the inner pair
THYSANOPTERA. 65
(c. 200 ~); mid-laterals and outer and inner antero-marginals approximately
140 to 174 inlength. Coxal seta long (c. 90 to 100). Outer margin of femora
strongly and closely setose, the setae on the fore-femur, which are the longest,
about 120 » in length. Fore-wings with 18 to 21 duplicated cilia.
Abdomen elongate; tube 0-9 or more the length of the head, gradually
narrowing to apex, where it is a little more than 0:5 as broad as at base ; terminal
Text-FIG. 3.—Gynaikothrips hystriz, sp. n. A, head and thorax; B, fore-leg; C, posterior
abdominal segments and tube; D, antenna.
hairs as long as the tube. Abdominal bristles long, as long as or longer than
the segments bearing them, those on 9 as long as or slightly longer than the
tube.
Length (and breadth) of head, pronotum and pterothorax 352(242) ;
230(440) and 580(607) » respectively ; length (and breadth near middle) of
fore-wing 1400(122) » ; length (and breadth) of fore-femur 344(175) w ; width
of abdomen 486 ». Length of tube 324, width near base 103, and at apex 54 wu.
66 INSECTS OF SAMOA.
$ smaller and more slender than the 9, with the tube about 0-85 the length
of the head. Tube with basal emargination deep. Abdominal bristles not so
strong or long as in the 9, those on segment 9 less than the length of the tube.
The pair of spines on segment 9 characteristic of the 3 long, about 67 p.
Tonga: Nukualofa, both sexes (but ¢¢ preponderating), and larvae in
rolled margins of Ficus leaves, 20.11.1925.
4. Gynaikothrips hopkinsi, sp. n. (Text-fig. 4).
®. Length about 2-8 to 3-0 mm.
Colour as in G. hystrix, with the fore-tibiae and tarsi darker than in that
species.
This species is nearly allied to G. hystrix, from which it differs chiefly in its
chaetotaxy. The cheeks have a decidedly dentiform angulation at the con-
striction behind the eyes, and are almost entirely devoid of setae except 2 short
ones (18 to 24 » in length) behind
the constriction ; postoculars somewhat
shorter, and the post-ocellar bristles
markedly shorter than in G. hystria.
Second antennal joint with an erect
sensory seta on the inner side at apex,
markedly stouter and longer than in
G. hystrix (48 to 54 » as compared with
36 to 40 ,).
Antenna 1-75 times as long as the
head ; joints somewhat shorter and
stouter than in G. hystrix, the relative
Text-FIG. 4.—Gynarkothrips hopkinsi, sp. un. lengths (and breadths) of 3 to 8 being ap-
A, head and thorax; B, fore-leg. proximately as follows: 100(46); 93(53) ;
92(50); 76(43); 68(35) ; 52(22) p.
Pronotum with the bristles somewhat shorter than in G. hystrix ; of those
at posterior angles, the inner micro-seta is usually normally small, but more
rarely well-developed, and at its maximum about 0-7 the leneth of that bristle.
The fore-coxal seta shorter than in G. hystrix, only about 40 » as opposed to
90 to 100 », and fore-femur along the outer margin with only two pairs of
prominent setae, one, the longer (c. 70 ~), near middle, and the other before
apex, the rest being minute (c. 17»). Mlicro-setae on outer margin of inter-
THYSANOPTERA. 67
mediate and posterior femora longer and stronger. Fore-wings with 18 dupli-
cated cilia.
Abdomen with long stout bristles, though not so long as in G. hystrix ;
those on segment 9 about 0-9 the length of the tube. Tube nearly as long as
the head, with the terminal hairs 0-8 to 0-85 as long as the tube.
Length (and breadth) of head, pronotum and pterothorax, 336(236) ;
209(405) ; and 540(512) » respectively ; length (and breadth near middle) of
fore-wing 1282(120) » ; length (and breadth) of fore-femur 324(155) ». Width
of abdomen 460 ». Length of tube 324, width near base 89 and at apex 41 pn.
3g. The male differs from the 2 in the same manner as in G. hystrix, and the
pair of spines on segment 9 are about as long, say c. 60 p.
Upolu: Apia, curling the leaves of Ficus, both sexes (with 33 pre-
ponderating) and larvae, 25.v.1925.
Genus Euoplothrips Hood.
Mem. Queensland Mus., vi, p. 140, 1918.
In describing this strongly characterised genus, Hood stated that “it is
without doubt a gall-making genus.” He described the genotype, Huoplothrips
bagnallr, from a single 2 taken by Mr. A. A. Girault, on May 30, 1912, by sweeping
in jungle at Nelson, North Queensland. In 1924, W. Docters van Leeuwen and
H. H. Karny published a paper on “ Two New Thrips-galls and their inhabitants,
from New South Wales” (Proc. Linn. Soc. N.S.W., xlix, Part 3, 1924), in which
leaf-galls on Randia chartacea F. v. M., and Smilax australis R. Br. are described.
Only two examples of Euoplothrips bagnalla were found in the former gall, but
in the latter both the Malayan Cryptothrips (?) intorquens K. (previously known
from two other species of Smilax), and LE. bagnalli were present, and, in view of
the present records, it would be safer to regard members of the genus EHuoplo-
thrips as inquilines rather than as gall-causers.
In the following descriptions (of females), HZ. buxtoni, sp. n., and E. incog-
nitus, Sp. n., are curiously analogous with the male forms recorded by Karny
as macromerous and micromerous L. bagnalli of Hood, but in these forms from
Tonga, which I can only regard as species, there are other differences apart
from size and structure of the fore-legs, such as in the comparative length of
the head and in the antennal joints, sub-basal bristles of the fore-wing, etc.
I have felt it wise, therefore, to ignore Karny’s forms (since they may
68 INSECTS OF SAMOA.
require further study when the genus is better known), and to base my com-
parisons upon Hood’s description alone.
From his description it will be seen that E£. bagnalli differs from the species
here described in its small size, short antennal joints 3 and 4, and in the sub-
equal sub-basal bristles of the fore-wing, and from E. buatoni and FE. incognitus
in its shorter head.
TABLE OF SPECIES (FEMALES).
1. Size smaller (2-16 mm.) ; antennal joints 3 and 4 not more than
2-0 times as long as broad ; sub-basal bristles of eee sub-
equal in length. Hab. Queensland : : . E. bagnalli Hood.
Size larger (3-3 to 4-0 mm.); antennal joints 3 and 4 more than
2-0 times as long as broad; sub-basal bristles of wings other-
wise. Hab. Samoaand Tonga. 2.
2. Head 1-6 times as long as broad, and tube 0 8 as Tene as shéad’;
basal production of fore-femur incurved and hook-like, with
corresponding recess in fore-coxa; antenna more slender,
having joint 3 shorter as compared with 4, and joint 7 longer
and more slender, nearly 3-5 times as long as broad ; sub-basal
bristles of fore-wing unequally spaced and unequal in length.
Hab. Samoa : : ; . HH. uncinatus, sp. n.
Head longer and tube comparatively shorter ; fore-femur basally
normal; antenna stouter, joint 3 erin mee longer and 7
shorter ; sub-basal bristles of fore-wing equidistant, 1 only 0-5
(or less) the length of 2 and 3, which are sub-equal. Hab. Tonga
3. Size large (3-7 to 4-0 mm.); head 2:0 times as long as broad;
antennal joint 3 more than 2-4 times, and 7 about 2-55 times as
long as broad. Fore-legs larger and armature stronger (see
figs.) ; 15 to 20 duplicated cilia in fore-wing . . £. buxtoni, sp. n.
Size smaller (3-3 mm.) ; head 1-8 times as Tone as broad’: antennal
joint 3 only 2-2 times, and 7 about 2-9 times as iene as broad.
Fore-legs smaller and armature weaker; 10 to 12 (duplicated
cilia in fore-wing . ; : 5 ; : ° . . £. incognitus, sp. n.
eo
5. Euoplothrips buxtoni, sp. n. (Text-fig. 5).
g. Length 3-7 to 4:0 mm.
Dark chestnut brown, fore tibiae and tarsi yellow, inner margin of fore
femur shaded to brownish-yellow with the spine-like production yellow, hind
and intermediate trochanters and tarsi light brown. Antennae with joints 1
and 6 to 8 of a uniform dark brown, 5 not so dark, 3 and 4 again somewhat paler
and somewhat mottled, especially basally and marginally, with yellowish-brown ;
2 apically and towards outer margin shading to yellowish-brown. Wings
THYSANOPTERA. 69
brownish-yellow, the upper with a dark brown longitudinal line near hind
margin, having the space below paler than the rest of the wing; hind wings
with a similar, but more nearly median, dark longitudinal line. Postocular,
prothoracic and lateral abdominal bristles pale ; wing cilia, dorsal abdominal
bristles and terminal hairs of tube fumate.
B. Hopkins
TExt-F1G. 5.—Euoplothrips buxtoni, sp. n. A, antenna; B, head and thorax; C, fore-leg.
Head long, approximately twice as long (to a line across eyes) as broad
across eyes, and about 2-7 times as long as broad near base, where it is 0-7 as
broad as across eyes. Cheeks regularly setose, the setae springing from raised
bases, sharp pointed, and from 20 to 25 » in length; post-oculars somewhat
long (130 to 150 »), almost as long as an eye, which latter occupies dorsally 0-3
the length of the head ; ocelli equidistant, the anterior ocellus overhanging and
on a line with the base of the antennae; posterior pair situated close to the
inner margins of eyes on a line drawn across their distal third. Antenna about
1-6 times as long as the head, much as in the genus Mesothrips ; joint 1 stout
but constricted in the distal third, 2 long compared to its breadth, which at
apex is much less than the greatest breadth of 3; 3-4 clavate, and distinctly
70 INSECTS OF SAMOA.
broader than the following: 5 and 6 elongate and less strongly claviform,
7 elongate and inclined to be claviform more than fusiform, and 8 broad
at base.
The relative lengths (and breadths) of antennal segments 3 to 8 are
approximately as follows: 146(60); 149(60); 138(46) ; 108(38); 84(33); and
48(19) ». Mouth cone very short, broadly rounded, and shorter than its basal
breadth.
Pronotum widening towards middle, then roundly straightened and again
broadened basally, where the sides are arcuate and the posterior margin gently
curved ; 1-2 times as broad before base as medianly long. Bristle at hind angle
pointed, somewhat curved and about 0:32 the length of the pronotum. Inner
postero-marginal and mid-lateral pair not so long and apparently more slender,
the latter being about 0-7 the length of the postero-angular ; antero-marginal
pairs more minute. Dorsal plate shield-like and having a well-defined median
line.
Fore-legs with the coxa elongated, dorsally flattened and the end truncate,
the hind angle rounded and the fore angle acute ; the coxal seta situated near
the hind angle, c. 100 » long and inclined to be curved.
Fore-femur 1-25 times as long as the head, and 0-5 as broad near middle
(excluding the spine-like production) as long; posterior margin (from the
trochanter) straight, but ending in a somewhat produced and rounded angle,
though not to anything like the extent seen in L. uncinatus, sp. n. (p. 73) ;
outer margin gently rounded ; inner margin emarginate near base, whence the
spine-like prolongation is gently curved upwards and somewhat inwards, after
which the margin is straight, narrowing to tip. Tibia stout, the median pro-
longation stout at base, then broadly thumb-like and about 0-6 as long as width
of tibia at the narrowest between the armature ; apical prolongation projecting
in a sharp angular tooth 0-3 as long as the width above defined. Tarsal tooth
beak-like and long, as long as or longer than the width of the tarsus (excluding
tooth), and more than 2-0 as long as the width near base. Hind and inter-
mediate legs stout, femora appearing inflated. 7
Fore-wings fourteen times as long as broad, with 15-15 duplicated cilia
in one specimen and 19-20 in the type. Sub-basal bristles consisting of 1
short erect and 2 longer, somewhat curved and relatively more slender ones,
the short one being 70 » in length, and only 0:5 as long as the others ; they are
separated from each other by 54 » and equidistant.
THYSANOPTERA. 71
Abdomen slender, narrower than pterothorax at segment 2 where it is
broadest ; tube 0-62 the length of the head, and about 0-3 as broad at base as
long; lateral bristles long, those on segment 9 nearly as long as the tube ;
terminal hairs about 0-85 the length of the tube.
Length of head and breadth across eyes and near base, 550, 280 and 200 p
respectively ; length of post-ocular bristle 130%; total length of antenna
850 » ; length (and breadth) of pronotum, pterothorax and fore-wing 350(420),
600(520), and 1750(128) » respectively. Length (and breadth) of femora and
tibiae, I, 700(350); 350(95); IL, 470(200); 326(95), and III, 540(240) ;
420(102) » respectively. Breadth of abdomen 540; length of tube and
breadth at base and apex 350, 110 and 58 p respectively.
Apart from being nearly twice the size, and somewhat different in colour,
this species differs from H. bagnalli, as described by Hood, in its stronger legs,
the larger series of duplicated cilia in the fore-wing, and the form of the sub-
basal bristles, and more particularly in the much longer head, as compared with
breadth across eyes, and apparently the more regularly and closely spinulose
cheeks. The postocular and pronotal setae are blunt in #. bagnalli, and the
former are much shorter than in £. buxtont. In EH. bagnalli the third and fourth
antennal joints are scarcely twice as long as broad, whereas in HL. buxtona they
are practically 2-5 times as long as broad; Karny figures the fore-legs of
what he calls the macromerous and micromerous males of H. bagnalli, the
former of which closely agrees with the fore-leg in the 2 of E. buaxtone.
Tonga: Nukualofa, 2 29 in galls of Gynaikothrips hystrix Bagn., 20.11.1925.
6. Euoplothrips incognitus, sp. n. (Text-fig. 6, C).
2. Length about 3-3.
Colour much as in E. buxtoni, but fore-femora not yellowish at inner margin,
and the spine-like projection yellowish-brown. Head only 1-8 times as long
as broad across eyes, and 2-4 times as long as broad near base, where it is about
0-75 as broad as across eyes. Relative length of eye to head, and of post-oculars
to eye as in E. buatont. Antennae also 1:6 times as long as head, but segment 7
relatively much longer as compared with 6 (81 : 92) than in HZ. buxtoni (84 : 108),
and more slender, being 2-9 as long as broad, whilst 3 is stouter as compared
with its length, being only 2-2 times as long as broad (as compared with more
than 2-4 in E. buztond).
12 INSECTS OF SAMOA.
The relative lengths (and breadths) of the antennae of the various species
may be tabulated as follows :
E. bagnalli Hood =. yw 83(46) ; 89(45) ; 81(36) ; 69(27); 57(22); 40(12).
E. buxtont Bagn. . p 146(60); 149(60); 138(46); 108(38); 84(33) ;
48(19)
E. incognitus, sp.n.. jy 125(54); 127(53); 119(45); 92(40); 81(28) ;
46(15)
E. uncinatus, sp.n.. p 120(54); 180(51); 122(42); 98(34); 90(26) ;
48(15).
The duplicated cilia in the fore-wing number 12, whilst the sub-basal bristles
are equidistant ; the first is erect and about 0:45 the length of the following
bristles which are curved and subequal in length (54: 122: 122 p).
Fore-legs normal, much as described in #. bagnalli, and of the type regarded
by Karny as micromerous (see Text-figs.), differing in their smaller size, the
shorter and more erect femoral spine, and the weaker armature of the tibia, the
distal tooth of which does not form the contour of the upper margin.
Tube 0-67 as long as head, and 0-32 as broad at base as long. Bristles of
abdominal segment 9 nearly as long as the tube, and the terminal hairs about
or a little more than 0-8 as long.
Length of head and breadth across eyes and at base 445, 245, and 182 p
respectively ; length of eye and of post-ocular bristle 135 and 122 » respec-
tively; length (and breadth) of pronotum and pterothorax 305(405) and
634(555) and length of postero-angular bristle 125 4. Breadth of abdomen
460 » ; length of tube and breadth at base and at apex, 300, 94 and 50 p respec-
tively. Length and breadth of femora and tibiae approximately I, 500(180) ;
243(74), II, 350(128) ; 284(68), and TI, 445(148) ; 350(74) pu.
3 very closely resembling the 2; in one specimen one wing has only 10
duplicated cilia and the other 12. The characteristic spine of the 9th abdominal
segment is 54 in length.
Tonga: Nukualofa, 1 Q and 2 gg in galls of Gynatkothrips hystrix Bagn.,
20.11.1925.
THYSANOPTERA. 73
7. Euoplothrips uncinatus, sp. n. (Text-fig. 6, A, B, D).
. Length about 3-5 mm.
This species differs from E. buxtont in its somewhat smaller size, distinctly
shorter head, which is only 1-6 times as long as broad across eyes, and short
post-oculars. In colour the fore-femora are dark, but inclined to be lighter at
the extreme apex and near the trochanters, while the spine-like production
is also yellow; the fore-tibia is more or less yellow to yellowish-brown, with
the outer margin dark brown, while the intermediate and hind tibiae are
yellowish at the knees. The antennae are more slender, being 1-28 times as
long as the head, and are lighter in colour, only joint 1 being concolorous with
the head ; jomt 3 is pale yellowish-white in the basal half, joints 4 and 5 are
also pale in the basal two-fifths, this pale area being ringed by a brownish band,
while 6 is generally paler in the basal third, sometimes being ornamented with
a darker ring; the last two joints are much more slender, whilst 7 is longer
than in HL. buxtoni, nearly as long as 6, and 3-5 times as long as broad, as com-
pared with little more than 2-5 times as long as broad in L. buztond.
The fore-legs are very characteristic; the coxa is different in form, and
appears to be strongly curved from the trochanter, so that the upper part is
raised over the hook-lke production of the femur; the femur is much as in
EB. buxtoni, except that the spine-like production is stouter, somewhat longer
and more forwardly directed, while posteriorly the femur is inwardly recurved
and narrowed into a hook-like end (which suggests the name), the coxa being
correspondingly recessed (as described above) for ease of movement.
The fore-coxal and pronotal bristles are shorter than in FE. buatoni
and stouter distally, being distinctly blunt and darker in colour.
The fore-wings have 15-15 duplicated cilia in the type (9), but 13 in the
3; the sub-basal bristles are dilated at the tip and unequally spaced, and the
second is situated on a slightly higher plane ; 1 and 2, and 2 and 3 are 42 » and
60 » apart respectively ; 1 and 2 are practically straight, 3 is longer and curved,
the respective lengths being 68, 79 and 98 yp.
The tube is 0-8 the length of the head, and 0:3 as broad at the base as long,
while the terminal hairs are 0-8 as long as the tube; the lateral bristles on
abdominal segment 9 are scarcely more than 0-6 as long as the tube.
Length of head and breadth across eyes and near base, 420, 260 and 180
respectively ; length of post-ocular bristle 48 » ; total length of antenna 130 p,
74 INSECTS OF SAMOA.
relative lengths and breadths of joints 3 to 8 respectively 120(54) ; 130(57) ;
122(42); 98(34); 90(26); and 48(15) ». Length (and breadth) of pronotum,
pterothorax and fore-wing 390(512); 675(620) and 1620(100) » respectively.
Length and breadth of femora and tibiae, I, 600(256) ; 270(90), II, 390(162) ;
338(73), and ITI, 500(190); 432(80) » respectively. Breadth of abdomen
B Hopkins
Text-Fié. 6.—Euoplothrips uncinatus, sp. n. A, antenna; B, fore-leg; D, head and thorax:
C, Euoplothrips incognitus, sp. u., fore-leg.
500»; length of tube and breadth at base and apex, 338, 100 and 54 yu
respectively.
The ¢ is slightly smaller and more slender but closely resembles the 9 ;
the 9th abdominal segment is furnished with the usual pair of spines, which are
pomted and 48 » in length.
The length of the head, and the breadth across the eyes and near the base
are 390, 235 and 150 p respectively, while the tube is only 284 » in length, and
88 and 48 » broad at base and apex respectively.
Upolu: Apia, 1 Q and 1 g in galls of Gynaikothrips hopkinsi Bagn.,
25.v.1925.
THYSANOPTERA. (6)
VIII. Description or A NEw Species OF RAAEBOTHRIPS.
Genus Rhaebothrips Karny.
Supplementa Entomologica (Deutsch. Ent. Mus.), No. 2, p. 128, 1913.
The genotype R. latwentris was described by Karny from material from
Formosa. In 1920 (Acta Soc. Ent. Cech., xvii, p. 42) the same author recorded
the winged form from Australia, and made further remarks in 1924 (Arkiv fur
Zoologi, K. Svenska Vetenskapsakademien, 17a, pp. 29-30, pl. IV, figs. 35 and 36).
The Australian record of R. latiwentris K. is interesting in view of the
discovery in Samoa of a second species of Rhaebothrips, as described below.
8. Rhaebothrips major, sp. n.
2. Length about 3-5 mm.
Colour dark chestnut brown, fore-tibiae and tarsi not quite so dark ; joints
1 and 5 to 8 concolorous with head, 2 distally paler, 4 dark grey-brown, but not
so dark as 5 and 8 a shade less dark than 4, with extreme base pale. Bristles
dark. Wings fumate, fore-wing with a dark blackish-brown median vein
reaching to beyond commencement of the duplicated cilia; lower wing more
lightly fumate, with a similar but thinner dark median vein, and a distinct brown
line between it and fore-margin as long as median vein, but not so near to it as
to fore-marein of wing.
Head to a line across fore-margin of eyes 1-6 times as long as greatest
breadth ; eyes small, about 0-23 the lateral length of head, vertex slightly
produced as base for the antennae ; cheeks somewhat arcuate from a little way
behind eyes, sparingly spinulose, with a somewhat stouter genal seta behind
eye. Mouth-cone very short, small. Post-ocular bristles very long (208 1),
over-reaching apex of first antennal joint ; interocellar pair also long. Antennae
long, twice as long as head to fore-margin of eyes ; joints 3 and 4 elongate and
somewhat claviform, subequal ; relative lengths (and breadths) of joints 3 to 8
approximately as follows: 148(42); 140(40); 120(32); 86(34); 60(27);
43(19) po.
Pronotum 0-7 to 0-75 as long as head, transverse and nearly twice as broad
as long ; bristles present, somewhat slender, pointed, those on posterior margin
the longest, the outer being about 0:6 as long as median length of pronotum.
Fore-coxal spine short. Fore-femur characteristic of the genus, bigger than
76 INSECTS OF SAMOA.
head, outer bend smoothly rounded, the inner geniculate, a long hair situated
on inner margin before bend, and upper inner margin somewhat swollen before
distal fourth or thereabouts; fore-tibia short, curved, and fore-tarsus with a
massive tooth. Pterothorax quadrate, wider than pronotum. Wings long,
fore-wing with 28 duplicated cilia.
Abdomen short, gently widening to segment 4 where it is widest, then
rapidly narrowing to the tube with the facies of Anactinothrips ; side margins
of segment 8 angulate near middle. Tube approximately as long as head,
and terminal hairs about 0-65 the length of the tube ; abdominal bristles long
and strong, those on 9 as long as tube. :
Length (and breadth) of head, pronotum and pterothorax 370(232) ;
540(284); and 620(—)p respectively. Length (and breadth) of wing
1485(108) pu.
Apart from its larger size, this species may readily be separated from
R. lativentris K. by the coloration of the fore-legs and antennae, as well as by
the longer series of duplicated cilia (28 compared with 17) in the fore-wing.
Upolu: Apia, 17.x1.1924.
LIST OF TEXT-FIGURES.
Text-fig. 1. Dimorphothrips microchaetus, sp. n. Posterior abdominal segments and tube.
,, 2. Dimorphothrips solitus, sp. n. A, head and thorax; B, fore-leg; C, posterior
abdominal segments and tube ; D, antenna.
» 3 Gynatkothrips hystriz, sp.n. A, head and thorax; B, fore-leg; C, posterior
abdominal segments and tube; D, antenna.
4. Gynaikothrips hopkinst, sp. n. A, head and thorax ; B, fore-leg.
, 5. Huoplothrips buxtoni, sp.n. A, antenna; B, head and thorax; C, fore-leg.
» 6. Huoplothrips uncinatus, sp. n. A, antenna; B, fore-leg; D, head and thorax.
C, Euoplothrips incognitus, sp. n., fore-leg.
PRINTED IN GREAT BRITAIN BY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES.
INSECTS OF SAMOA
AND OTHER SAMOAN TERRESTRIAL
ARTHROPODA
LIST OF PARTS AND SYSTEM OF PUBLICATION :—
Pare 1
. Hemiptera.
ale
VAIL
Orthoptera and Dermaptera.
Lepidoptera.
. Coleoptera.
_ Hymenoptera.
. Diptera.
Other Orders of Insects.
Terrestrial Arthropoda other than Insects.
_ The work will be published at intervals in the form of numbered fascicles.
Although individual fascicles may contain contributions by more than one
author, each fascicle will be so arranged as to form an integral portion of one or
other of the Parts specified above.
INSECTS OF SAMOA
AND OTHER SAMOAN TERRESTRIAL
ARTHROPODA
List of Fascicles issued to 231d Tae. 1928 :-—
Date Tae
Insects of Samoa and other Samoan Terrestrial Arthropoda. Maps 1 and Rae ice a
2 (in envelope). 1927, 4to. 6d. : 26th February, 1927.
Part II. HemiprTera. ¥ :
K a - Fulgoroidea. By F. Muir. 25 text-figures. Psyllide (Chermide).. m
4 rawford. 4 text-figures. Coccide, \ ide. Toad ae
By F. Laing MAG BSc: 3 text neures.” Pp: [245s 1827, Feat areas aie ZOE See ema
Fasc. 2. Cercopide. By V. Lallemand, M.D. 10 text-figures. Cicadide. By —_— i
yers, Sc.D. 22 text-figures. Aquatic and Semi-aquatic Heteroptera.
by Prof. Teiso Esaki. 6 text-figures. Pp. 47-80. 1928, Ato. 2s. éd. 23rd June, 1928.
Part Il]. Leprpoprera. we ee Visa
Fasc. 1. Butterflies of Samoa and some neighbouring Island-gr. By G.H. E.
Topline WEA hes | text-figure an 4 pl Wstes Pp. | ‘a 1927, LS 3s. 9th April, 1927. Ny
Fasc. 2. Micro-Lepidoptera. By Edward Meyrick, B.A. F.R.S. Pp. 65-116.
1927, 4to. 2s. 6d. | 28th May, 1927.
Fasc. 3. Geometride. By Louis B. Prout, F.E.S. 2 text-fi d | plat Age
Ble 1 el eek Cn on 8 QAth Maret $O2RD
Part IV. CoLropTera.
Fasc. 1. Carabide. By H. E. Andrews. 9 text-figures. Dytiscide. By A.
Dintrermange kone heures. Staph: inide. By M. Cameron, M.B. 2 text-
figures. Hydrophilide. rchymont, | text-figure. Clavicornia and Peso
Lamellicronia. By G. J. meee a 13 text-figures, Pp. 1-66. 1927. 4to. 3s. 19th December, 1927.
Fasc. 2. Heteromera, Peano Peete oe Buprestide. By K.G..
Blair, B.Sc. 14 text- cheutce. Elaterid ae R. H. van Zwaluwenberg. 10
text-fgures. ae ze eu z). By i Fleutiaux. Cerambycide. By
Chr. nes iN late. Pet “ ez. By R. Kleine. 4 text-figures. Mie
Anthribide. Kath Jordan, Ph.D. 11 saves Proterhinide. By Eta
RG a: eed D ‘Sc. és R. 5. Pe 67-174. 1928. 4to. 5s. 2th February, 1928. ;
‘Part V. Hymenoprera.
Fasc. 1. Apoidea, Sphecoidea, and Vespoidea. By R. C. L. Perkins, D.Sc.,
He ; whee eae Sipe eS con ne oe ree eae :
text~ faut Ol ft: i :
en IOI dee Sn a me" 25th February, 1928.
Part VI. Drprera. need
F; 1 Streblide and Nycteribiide. By L. Fal 7 text-fi Hippo-
Toscidiog By C.F reties| Otextligures. Py l-oli W27 do, 2a Gl. )) | 2See tant ae
Fasc. 2. Nematocera. ByF.W.Edwards, M.A. 20text-figures. Cecidomyiine.
By H. F. Barnes, BA. P D. 4 text-figures. Pp. 23-108. 1928, 4to. 5s. 23rd June, 1928.
Part VII. Otter Orpers or INsEcTs.
Fasc. 1. Isoptera: ed Leame: en Gerald F. ce 14 text-figures and
| plate. Odonata. By Lt.-Col. F. raser, 1.M.S., F.E.S. 5 text-figures.
Pp. I-44. 1927, 4to. | 2s. 6d. 28th May, 1927.
Fasc. 2. Plectoptera. By a J. hes on (Cantab.), F.R.S., and J. A. ee
Lestage. 2 text-figures. Ronaptere, 5 P. A. Buxton, M.A. Thysano tera.
RSE ELS. Chechens Py. 45-76) 1998 ate
By Richard S. Bagnall, FR es itt
Bed ee 23rd Jane, 1926-4. aae
Part VIII. Terrestr1AL ARTHROPODA OTHER THAN INSECTS. iN
Fasc. 1. lsopede Terrestria. By Harold G. Jackson, DSc. 2 plates. Scor-
pionoidea, uxton . Pseudo-scorpiones. By A. Kistner.
ee Agana? By Stanley Hirst. 2 text-figures. dine! 1-27. 1927, 23rd July, | on!
au Saal
Lene hed ee eS
set Sera