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CORNELL

UNIVERSITY

LIBRARY

BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND GIVEN IN 1 89 1 BY

HENRY WILLIAMS SAGE

Date Due

FEB,&r=S

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Cornell University Library QL 43.C17 1895 "■^ Cambridae natural gto|

Cornell University Library

The original of this book is in the Cornell University Library.

There are no known copyright restrictions in the United States on the use of the text.

http://www.archive.org/details/cu31924024535480

THE

CAMBRIDGE NATURAL HISTORY

EDITED BY

S. F. HARMER, Sc.D., F.R.S., Fellow of King's College, Cambridge : Superintendent of the University Museum of Zoology

A. E. SHIPLEY, M.A., Fellow of Christ's College, Cambridge; University Lecturer on the Morphology of Invertebrates

VOLUME VI

INSECTS

PART II. Hymenoptera ci'«/'z'«z^^i/ (Tubulifera and Aculeata), Coleoptera, Strepsiptera, Lepidoptera, Diptera, Aphaniptera, Thysanoptera, Hemiptera, Anoplura.

By David Sharp, M.A. (Cantab.), M.B. (Edinb.), F.R.S.

ILontion

MACMILLAN AND CO., Limited

NEW YORK: THE MACMILLAN COMPANY I 90 I

All riff Ills reserved

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"Men are poor things; I don't know why the world thinks so much of them." Mrs. Bee, by L. & M. Wintle.

First Edition i8c Reprinted igor

CONTENTS

PiGE

Scheme of the Classification adopted in this Book . vii

CHAPTER I

Hymenopteua' Petiolata continued Series 2. Tubulifeea ok Cheysi- DiDAE. Series 3. Aculeata General Classification Division I. Anthophila or Bees . ...... 1

CHAPTER II

Hymenopteua Aculeata continued Division II. Diplopteka or Wasps EuMENiDAE, Solitary True "Wasps Vespidae, Social Wasps JIasaridae ... . . . .

CHAPTER III

Hymenoptera Aculeata continued Division III. Fossores or FossoEiAL Solitary Wasps Family Scoliidab or Subterranean Fossores Family Pompilidae or Runners Family Sphegidae or Perfect-Stingers . .... 90

CHAPTER IV

Hymenoptera Aculeata continued Division IV. Formicidae or

Ants . . .131

CHAPTER V Coleopteea or Beetles Strepsiptera . ... 184

CHAPTER VI Lbpidoptera, or Butterflies and Moths . . . . 304

CONTENTS

CHAPTER VII

PAGE

DiPTEKA, OR Flies Aphaniptera, or Fleas Thysanopteea, oe Theips 438

CHAPTER VIII

Hemiptera, ok Bugs Anopluka 532

Notes . . .... 602

Index ...... . ... 603

SCHEME OF THE CLASSIFICATION ADOPTED IN THIS BOOK

Order.

Sub-order, Division, or Series.

Family.

Sub-Family or Tribe.

Group.

HYMENOPTERA ( Petiolata.

{continued from I {continticd Vol. r). [from Vol. V).

( Tubulifera | chrysididae (p.

HYMENOPTERA

{continued)

(P- 1)

1).

i

Aculeata

(r- 4)

Anthophila (p. 10) Apidae (p.

10)

DiPLOPTERA

(p. 71)

("EUMENIDAE (p.

■j Vespidae (p. 7 (, Masap.idae (i

' Archiapides (p. 21).

Obtusilingues (p. 22).

Andrenides (p. 23).

Denudatae (p. 29).

Scopulipedes (p. 32).

Dasygastres (p. 35). ^ Sociales (p. 53).

72).

FOSSORES (p, 90) SCOLIIDAE (p. 91)

Sphegidae (p. 107)

Mutillides (p. 94). Thynnides (p. 96). Scoliidcs (p. 97). Sapygides (p. 99). . Rliopalosomides (p. 100). POMPILIDAE (p. 101).

' Sphegides (p. 107). Anipulicides (p. 114). Larrides (p. 116). Try poxy] onides (p. 118). Astatides (p. 119). Bembecides (p. 119). Nyssonides (p. 123). Philanthides (p. 124). Mimesides (p. 127). Crabronides (p. 128).

'Camponotides (p. 144). Doliohoderides (p. 157).

Myrmicini

Hetbrogyna (p. 131) FOKMICIDAE (p. 131)

Myrmicides (p. 158;

(p. 159).

Attiiii (p. 165)._

Pseudoniynnini

(p. 168). Cryptocerini

(p. 169).

Ecitonini

Ponerides (p. 170).

n

Dorylides (p. 174)- o^ii^Y^^"

I (p. 177). AmblyopoTiides (p. 180).

SCHEME OF CLASSIFICATION

Sub-Order, Division, or Series.

Family.

Sub-Family or Tribe.

COLEOPTEKA

(p. 184)

Lamelli- cornia

(p. 190

Adephaga or Caraboidea

(p. 200)

Poljmiorpha

(p- 213)

{Continued on the next ]}a-ge.)

'Passalidae (p. 192).

LUCANIDAE p. 193).

SCARABAEIDAE

(p. 194)

rCoprides (p. 195).

lleloloiithides (p. 198). -, Rutelides (p. 198).

Dynastides (p. 199). (_Cetoniides (p.

J

199).

/• CiCINDELIDAE (p. 201).

[ Carabides (p. 206). Cak.IlBIDAE I Harpalides (p. 206).

(p. 204) 'I Pseudomorphides (p. 206). t Mormolycides (p. 206).

Amphizoidae (p. 207). Pelobiidae (p. 207). Haliplidae (p. 209). "^ Dytlscidae (p. 210).

Paussidae (p. 213). Gyrinidae (p. 215).

HYDltOPHILIDAE (p. 216).

Platypsyllidae (p. 219). Leptinidae (p. 220).

SiLPHIDAE (p. 221).

Scy'dmaenidab (p. 223). Gnostidae (p. 223). Pselaphidae (p. 223). Staphy'linidab (p. 224). Sphaeeiid.ae (p. 227). Triohopterygidae (p. 227). Hy'drosoaphidae (p. 228).

CuRYLOPHIDAE (p. 228).

SoAPHinnDAE (p. 229). Synteliid.ae (p. 229).

HiSTERIDAE (p. 230).

Phalaceidae (p. 231).

NlTIDULIDAE (p. 231).

Trogositidae (p. 232). Coly'diidae (p. 233). Rhysodidae (p. 234). CUCUJIDAE (p. 234). Cryptophagidae (p. 235). Helotidae (p. 23f ). Thoeictidae (p. 236). Er.OTYLIDAE (p. 236). JMy'cetophagidae (p. 237).

COCCINELLIDAE (p. 237).

Endomychidae (p. 239). Mycetaeidae (p. 239). Latridiidae (p. 240).

AlUMERIDAE (p. 240).

Dermestidae (p. 241). Byrrhidae (p. 242). Cy'athoceridae (p. 243). Georyssidae (p. 243). Hbteroceridae (p. 243). Parkidae (p. 243). IDerodostidae (p. 244).

SCHEME OF CLASSIFICATION

Order.

Sub Order, Division, or Series.

Polymorpha

(continued)

COLEOPTEEA

{continued)

Heteromera

(p. 262)

Phytophaga

(p. 276)

Family

ClOIDAE (p. 245). Sphindidae (p. 245). BOSTRICHIDAE (p._246)

Ptinidae (p. 246)

Malacoder-

MIDAE

(p. 248)

Sub- Family or Tribe.

7 Pfinides (p. 246) \ Anobiides (p. 246).

r Lycides (p. 248).

I Drilides (p. 248).

i La.mpyrides (p. 248).

[ Telephorides (p. 248). Melyridae (p. 252). - Cleridae (p. 253) Lymexylonidae (p. 254).

D.ASCILLIDAE (p. 255).

Rhipioeridae (p. 256).

Throscides (p. 260). Eucuemides (p. 260). El.vperid.ae Elaterides (p. 260).

(p. 256). ] Cebrionides (p. 260). Perotliopides (p. 260). I Cerophytides (p. 260). . BtJPRESTIDAE (p. 261).

Tenebrionidae (p. 263).

CiSTELIDAE (p. 264).

Lagriidab (p. 264). Othniidae (p. 265). Aegiai.itidae (p. 265).

MONO.MMIDAE (p. 265). NiLIOXIDAE (p. 265). Melandryidae (p. 265). Pythidae (p. 265). Pyrochroiuae (p. 266). AyTHICIDAE (p. 266). Oedemeridae (p. 266).

MORDELLIDAE (p. 267).

Cantharidae (p. 269).

^TllICTENOTOMIDAE (p. 275).

f Bruohidae (p. 276)

r Eupoda (p. 280). Chry'somel- I Camptosomes (p. 281). IDAE (p. 278)1 Cyolica (p. 282).

t Cryptostomes (p. 282).

f Prionides (p. 287). .EJ (- - ■«

Ehynoho- phora(p. 288)

Ceramby-cidaeJ c.a^bycides (p. 287). (p. 28o) y Lamiides (p. 287).

C Anthribtiiae (p. 290).

I CURCUUONIDAE (p. 290).

■j Soolytidae (p. 294). 1,Brenthidae (p. 295). f Aglycydebidae (p. 297). [ Proterhinidae (p. 298).

^*r'^298T^ {STYLOPIDAE(p. 298).

SCHEME OF CLASSIFICATION

Order.

Sub-Order, Division, or Series.

Family.

Sub-Family or Tribe.

LEPIDOPTEEA

(p. 304)

Ehopalooera

(p. 341)

Heterocera

(p. 366)

' Danaides (p. 344). Ithomiides (p. 346). Satyrides (p. 347). NYMPH..i.LiDAE Morphides (p. 348). (p. 343} ] Brassclides (p. 349).

Acraeides (p. 350). Heliooniides (p. 351. Nymphalides (p. 352). Ekycixidae / Erycinides (p. -355).

(p. 354) 1 Libytheides (p. 355).

Lycaenidae (p. 366).

PlERIDAE (p. 357).

Papilionidae (p. 359). Hespeuiidae (j). 363. Castniidae (p. 371). Neocastniiuae (p. 372). Saturniidae (p. 372). Bkahmaeidae (p. 374). Ceratocampidae (p. 375).

BOMBYCIDAE (p. 375). EUPTEROTIDAE (p. 376).

Perophoridae (p. 377). Sphingidae (p. 380).

COCYTIIDAE (p. 382). NOTODONTIDAB (p. 383).

Cymatophoeidae (p. 386). Sesiidae (p. 386). Tinaegeriidae (p. 387). Syntomidae (p. 388). Zygaenidae (p. 390). Himantopteridae (p. 392). Heterogynidae (p. 392). Psychidae (p. 392). CcssiDAE (p. 395). Akbelidae (p. 396). Cheysopolomidae (p. 396). Hepiaudae (p. 396). •j Callidulidae (p. 400). Drepanidae (p. 400). Limacodidae (p. 401). AIegalopy'gidae (p. 404). Thyrididae (p. 404). Lasiocampidae (p. 405). Endromidae (p. 406). Pterothysanidae (p. 406). Lymantriidae (p. 406). Hyp.sidae (p. 408). Arctiidae (p. 408). Agarlstidae (p. 410). Geometridae (p. 411).

NOCTUIDAE (p. 414).

Epicopeiidae (p. 418). Ukaniidae (p. 419). Epiplemidae (p. 420). Pyralidae (p. 420). Pterophoridae (p. 426). Alucitidae (p. 426).

TOETRICIDAE (p. 427). TiNEIDAE (p. 428). Eriocephalidae (p. 433). IMlCKOPTERYGIDAE (p. 435).

SCHEME OF CLASSIFICATION

Order.

Sub-Order, Division, or Series,

Family.

Sub-Family or Tribe.

DIPTEEA

(p. 438)

Orthorrha- pha Nemo- cera

(p. 455)

' Cecidomyiidae (p. 458). Myoetophilidae (p. 462). Blepharoceridae (p. 464).

CULICIDAE (p. 466).

Chikonomidae (p. 468). Orphnephilidae (p. 470).

PSYCHODIDAE (p. 470). DiXIDAE (p. 471).

TiPULIDAE

(p. m)

BiBIONIDAE SlMULIIDAE (p. 477)

1,Rhyphidae (j). 478).

( Ptychopterinae (p. 472) '. Limnobiinae (p. 473). \ Tipulinae (p. 475). 475).

Orthorrha- pha Bra- chycera

(pp. 455, 478)

Cyolorrha- pha As- chiza

(pp. 455, 494)

Cyclorrha- pha Schi- zophora

(pp. 456, 503)

Pupipara

(pp. 456, 517)

Stratiomyidae (p. 478). Leptidae (p. 479). Taeanidae (p. 481).

ACANTHOMERIDAE (p. 483).

Therevidae (p. 484).

SCENOPINIDAE (p. 484).

Nbmestrinidae (p. 484).

BOMBYLIIDAE (p. 485). ACROOEKIDAE (p. 489). LONOHOPTERIDAE (p. 490).

Mydaidae (p. 491).

ASILIDAE (p. 491).

Apioceridae (p. 492). Empidae (p. 492).

DOLICHOPIDAE (p. 493).

' Phoridae (p. 494). Platypezidae (p. 496). Pipunoulidae (p. 496).

CONOPIDAE (p. 497).

^Syrphidae (p. 498). Ml'scidae Acalyptratak (p. 503).

ASTHOMYIIDAE (p. 506).

Tachinidae (p. 507). Dbxiidae (p. 510). Sakcophagidae (p. 510).

MUSCIDAE (p. 611).

^Oestridae (p. 514).

'HiPPOBOSClDAE (p. 518).

Braulidae (p. 520). Streblidae (p. 521). ^ Nycteribiidae (p. 521).

APHANIPTEEA f (pp. 456, 522) I.

Pulioidae (p. 522).

THYSAUO- / Terebrantia (p. 531).

PTERA (p. 526) V Tubulifera (p. 531).

SCHEME OF CLASSIFICATION

Sub-Order.

Series.

HEMIPTERA

(p. 532)

Heteroptera

(PP- 543, 544)

Gymnocek-

ATA (p. 544)

Ceyptocek-

ATA (p.

562)

Hojmoptera

(pp. 543, 568)

I Anoplura l- {p. 599.)

Tkimera

544)

(p.

DiMEBA

544)

MOXOMEEA

(p. 544).

(P-

Family. (• Pentatomidae (p. 545).

COREIDAE (p. 546).

Berytidae (p. 548). Lygaeidae (p. 548). Pyrrhocokidae (p. 549).

TiNGIDAE (p. 549).

Aradidae (p. 550). Hebridae (p. 551). Hydrometkidae (p. 551). Henicocephalidae (p. 554). Phyjiatidae (p. 554). Reduviidae (p. 555). Aepophilidae (p. 559). Ceratocombidae (p. 559).

CiMICIDAB (p. 559). Anthocoridae (p. 560).

POLY'CTENIDAB (p. 560).

Capsidae (p. 561). Saldidae (p. 562).

Galgulidae (p. 562). Nepidae (p. 563). Naucoridae (p. 565). Belostomipae (p. 565).

NOTOXECTIDAE (]>. 567).

Corixidae (p. 667).

{CiCADTDAE (p. 568). FULGORIDAE (p. 574). Membracidae (p. 576). Gercopidae (p. 577). Jassidae (p. 578).

PSYLLID.AE (p. 578).

Aphidae (p. 681). Alel-rodidae' (p. 691).

COCCIUAE (p. 592).

Pediculidae (p. 599).

CHAPTEE I

HYMENOPTERA PETIOLATA CONTINUED

SERIES 2. TUBULIEERA OR CHKYSIDIDAE SERIES o. ACULEATA

GENERAL CLASSIFICATION DIVISION L ANTHOPHILA OR BEES

The First Series Parasitica of the Sub-Order Hymenoptera Petiolata was discussed in the previous volume. We now pass to the Second Series.

Series 2. Hymenoptera Tubulifera.

Trochanters uncliviclecl ; the hind-hody consisting of from three- to five visible segme7its ; the female with an ovipositor, us'ucd'ly retracted, transversely segmented, enveloping a fine, pointed style. The larvae usually live in the cells of other Hymenoptera.

The Tubulifera form but a small group in comparison with Parasitica and Aculeata, the other two Series of the Sub-Order. Though of parasitic habits, they do not appear to be closely allied to any of the families of Hymenoptera Parasitica, though M. du Buysson suggests that they have some affinity with Proctotrypidae ; their morphology and classification have been, however, but little discussed, and have not been the subject of any profound investi- gation. At present it is only necessary to recognise one family, viz. Chrysididae or Euby-wasps.^ These Insects are usually of glowing, metallic colours, with a very hard, coarsely-sculptured integument. Their antennae are abruptly elbowed, the joints not being numerous, usually about thirteen, and frequently so

^ Systematic monograph, Mocsary, Budapest, 1889. Account of the European Chrysididae, E. da Buysson in Audrii, Spec. gen. Mym. vol. vi. 1896.

VOL. VI 3E B

HYMENOPTERA

CHAP.

connected that it is not easy to count them. The abdomen is, in the great majority, of very pecidiar construction, and allows the Insect to curl it completely under the anterior parts, so as to roll up into a little ball; the dorsal plates are very strongly arched, and seen from beneath form a free edge, while the ventral plates are of less hard consistence, and are connected with the dorsal plates at some distance from the free edge, so that the abdomen appears concave beneath. In the anomalous genus

Cleptes the abdomen is, however, similar in form to that of the Aculeate Hymen- optera, and has four or five visible seg- ments, instead of the three or four that are all that can be seen in the normal Chrysididae. The

larvae of the Euby- fiies have the same number of segments as other Hymenoptera Petiolata. The difference in this re- spect of the perfect Chrysididae from other Petiolata is due to a greater number of the terminal segments being indrawn so as to form the tube, or telescope-like structure from which the series obtains its name. This tube is shown partially extruded in Fig. 1 ; when fully thrust out it is seen to be segmented, and three or four segments may be distinguished. The ovipositor proper is concealed within this tube ; it appears to be of the nature of an imperfect sting ; there being a very sharply pointed style, and a pair of enveloping sheaths ; the style really consists of a trough-like plate and two fine rods or spiculae. There are no poison glands, except in Cleptes, which form appears to come very near to the Aculeate series. Some of the Chrysi- didae on occasions use the ovipositor as a sting, though it is only capable of infiicting a very minute and almost innocuous wound. Although none of the Euby-flies attain a large size, they are usually very conspicuous on account of their gaudy or brilliant colours. They are amongst the most restless and rapid of Insects ;

Fig. 1. Ohrysis igiiita, ?. England.

CHRYSIDIDAE

they love the hot sunshine, aiid are diflicult of capture. Though not anywhere numerous in species, they are found in most parts of the world. In Britain we have about twenty species. They usually frequent old wood or masonry, in which the nests of Aculeate Hymenoptera exist, or fly rapidly to and fro about the banks of earth where bees nest. Dr. Chapman has observed the habits of some of our British species.^ He noticed Chrysis ignita flying about the cell of Odyncrus iMrietum, a solitary wasp that provisions its nest with caterpillars ; in this cell the Chrysis deposited an egg, and in less than an hour the wasp had sealed the cell. Two days afterwards this was opened and was found to contain a larva of Chrysis a quarter of an inch long, as well as the Lepidopterous larvae stored up by the wasp, but there was no trace of egg or young of the wasp. Six days after the egg was laid the Chrysis had eaten all the food and was full- grown, having moulted three or four times. Afterwards it formed a cocoon in which to complete its metamorphosis. It is, however, more usual for the species of Chrysis to live on the larva of the wasp and not on the food ; indeed, it has recently been positively stated that Chrysis never eats the food in the wasp's cell, but there is no ground whatever for rejecting the evidence of so care- ful an observer as Dr. Chapman. According to M. du Buys- son the larva of Chrysis will not eat the lepidopterous larvae, but will die in their midst if the Odynerus larva does not de- velop ; but this observation probably relates only to such species as habitually live on Odynerus itself. The mother-wasp of Chrysis bidentata searches for a cell of Odynerus spinipes that has not been properly closed, and that contains a full-grown larva of that wasp enclosed in its cocoon. Having succeeded in its search the Chrysis deposits several eggs from six to ten ; for some reason that is not apparent all but one of these eggs fail to pro- duce young ; in two or three days this one hatches, the others shrivelling up. The young Chrysis larva seizes with its mouth a fold of the skin of the helpless larva of the Odynerus, and sucks it without inflicting any visible wound. In about eleven days the Chrysis has changed its skin four times, has consumed all the larva and is full-fed ; it spins its own cocoon inside that of its victim, and remains therein till the following spring, when it changes to a pupa, and in less than three weeks there-

1 ^9!!!. Mag. vi. 1869, p. 153.

HYMENOPTERA chap.

after emerges a perfect Chrysis of the most brilliant colour, and if it be a female indefatigable in activity. It is remarkable that the larva of Chrysis is so much like that of Odynerus that the two can only be distinguished externally by the colour, the Odynerus being yellow and the Chrysis white ; but this is only one of the many cases in which host and parasite are extremely similar to the eye. Chrysis shanyhaiensis has been reared from the cocoons of a Lepidopterous Insect Moneina flavescens, family Limacodidae and it has been presumed that it eats the larva therein contained. All other Chrysids, so far as known, live at the expense of Hymenoptera (usually, as we have seen, actually consuming their bodies), and it is not impossible that C. shang- haieti'Sis really lives on a Hymenopterous parasite in the cocoon of the Lepidopteron.

Farnojxs carnea frequents the nests of Bembex rostrata, a solitary wasp that has the unusual habit of bringing from time to time a supply of food to its young larva ; for this purpose it has to open the liest in which its young is enclosed, and the PnriwjJes takes advantage of this habit by entering the cell and depositing there an egg wdiich produces a larva that devours that of the Bembex. The species of the anomalous genus Cleptes live, it is believed, at the expense of Tenthredinidae, and in all prob- ability oviposit in their cocoons which are placed in the earth.

Series 3. Hymenoptera Aculeata.

The females (;ivhether luorkers or true femcdes) j)rovidcd. vnth a sting: trochanters usually undicided {monotrochous). Usually the antennae of the males tvith thirteen, of the females vnth twelve, joints {exeeptio7is in ants numerous).

These characters only define this series in a very unsatisfac- tory manner, as no means of distinguishing the " sting " from the homologous structures found in Tubulifera, and in the Procto- trypid division of Hymenoptera Parasitica, have been pointed out. As the structure of the trochanters is subject to numerous exceptions, the classification a.t present existing is an arbitrary one. It would probably be more satisfactory to separate the Proctotrypidae (or a considerable part thereof) from the Para- sitica, and unite them with the Tubulifera and Aculeata in a great series, characterised by the fact that the ovipositor is

ACULEATA

withdrawn into the body in a direct manner so as to be entirely internal, whereas in the I'arasitica it is not withdrawn in this manner, but remains truly an external organ, though in numerous cases concealed by a process of torsion of the terminal seg- ments. If this were done it might be found possible to divide the great group thus formed into two divisions characterised by the fact that the ovipositor in one retains its function, the egg

Fig. 2. Diagram of iipper sur- face of Priocnemis ajfinis 9 , Pompilidae. o, ocelli ; 7J^, pronotuni ; 7J^, mesonotum ; B^, sciitellum of mesonotnni ; B^, post-scutelluni or middle part of metanotum ; h^, propo- deum or median segment (see vol. V. p. 491) ; Js'^, combing hairs, pecten, of front foot: C, first segment of abdomen, here not forming a pedicel or staik : Z)^, coxa; />^, trochanter; D'-^, femnr ; JJ^, calcaria or spurs of liind leg: 1 to 15, nerv- nres of wings, viz. 1, costal ; 2, post -costal ; 3, median ; 4, posterior ; 5, stigma ; 6, marginal ; 7, upper basal ; 8, lower basal ; 9, 9, cubital ; 10, tlie three sub- marginal ; 11, lirst recurrent ; 12, second recurrent; ];% anterior of hind wing ; 1-), median ; 15, posterior : I to XI, the cells, viz. I, upper basal ; II, lower basal ; III, marginal ; IV, V, \l, first, second and third sub-mar- ginal ; VII, first discoidal ; VIII, third discoidal ; IX, second discoidal ; X, first apical ; XI, second apical.

passing through it (Proctotrypidae and Tubulifera), while in the other the organ in question serves as a weapon of offence and defence, and does not act as a true ovipositor, the egg escaping at its base. It would, however, be premature to adopt so revolu- tionary a course until the comparative anatomy of the organs concerned shall have received a much greater share of attention.^ We have dealt with the external anatomy of Hymenoptera in

1 For new views on this subject see note on p. 602.

HYMENOPTERA

Vol. V. ; SO that here it is only necessary to give a diagram to explain the terms used in the descriptions of the families and sub-families of Aculeata, and to discuss briefly their characteristic structures.

The Sting of the bee has been described in detail by Kraepelin, Sollmann, Carlet ■' and others. It is an extremely perfect me- chanical arrangement. The sting itself independent of the sheaths and adjuncts consists of three elongate pieces, one of them a gouge-like director, the other two pointed and barbed needles ; the director is provided with a bead for each of the needles to run on, these latter having a corresponding groove ; the entrance to the groove is narrower than its subsequent diameter, so that the needles play up and down on the director

with facility, but cannot be dragged away from it ; each needle is provided with an arm at the base to which are attached the muscles for its movement. This simple manner of describing the mechanical arrangement is, however, incomplete, inas- much as it includes no account of the means by which the poison is conveyed. This is done by a very com- plex set of modifications of all the parts ; firstly, the director is enlarged at the anterior part to form a A, One of the needles chamber, through which the

Fig. 3.— Stins of bee.

,,. - J *' Pift"" ; needles play ; the needles are

arm. B, 'Iransver-se section of the . , ,

separated ; a, the barbed point ;

sting : del, the two needles ; e, bead for ^ach provided with a pro guiding the needles ; /, director iff' channel of poison. (After Carlet.)

jecting piece, which, as the needle moves, plays in the chamber of the director, and forces downwards any liquid that may be therein ; the poison-glands open into the chamber, and the projections on the needles, acting after the manner of a piston, carry the poison before them. The needles are so arranged on

' Ann. Sci. Nat. {7) ix. 1890, p. 1.

ACULEATA STING LARVA 7

the director that they enclose between themselves and it a space that forms the channel along which the poison flows, as it is carried forwards by the movement of the pistons attached to the needles. If the needles be thrust into an object quite as far as, or beyond, the point of the director much poison may be introduced into a wound, as 'the barbs are provided with small orifices placed one above the other, while if this be not the case much of the liquid will flow on the outside of the object.

According to Carlet the poison of the bee is formed by the mixture of the secretions of two glands, one of which is acid and the other alkaline; it is very deadly in its effects on other Insects. We shall see, however, that the Fossorial Hymenoptera, which catch and sting living prey for their young, frequently do not kill but only stupefy it, and Carlet states that in this group the alkaline gland is absent or atrophied, so that the poison con- sists only of the acid ; it is thus, he thinks, deprived of its lethal power. Moreover, in the Fossoria the needles are destitute of barbs, so that the sting does not remain in the wound. Bordas, however, states ^ that in all the numerous Hymenoptera he has examined, both acid and alkaline glands exist, but exhibit considerable differ- ences of form in the various groups. He gives no explanation of the variety of effects of the poison of different Aculeata.

The larvae (for figure of larva of Bomliis, see Vol. V. p. 488) are, without known exception, legless grubs, of soft consistence, living entirely under cover, being protected either in cells, or, in the case of social Hymenoptera, in the abodes of the parents. The larvae of Ants and fossorial Hymenoptera have the anterior parts of the body long and narrow and abruptly flexed, so that their heads hang down in a helpless manner. All the larvae of Aculeates, so far as known, are remarkable from the fact that the posterior part of the alimentary canal does not connect with the stomach till the larval instar is more or less advanced ; hence the food amongst which they live cannot be sullied by faecal matter. The pupa is invariably soft, and assumes gradually the colour of the perfect Insect. Almost nothing is known as to the intimate details of the metamorphosis, and very little as to the changes of external form. According to Packard a period inter- venes between the stadium of the full-grown larva and that of the pupa, in which a series of changes he speaks of as semi-pupal

> C. B. Ac. Paris, cxviii. 1894, p. 873.

HYMENOPTERA

are passed through ; these, however, have not been followed out in the case of any individual, and it is not possible to form any final idea about them, but it seems probable that they are largely changes of external shape, in conformity with the great changes going on in the internal organs. Owing to the fragmentary nature of observations, much obscul-ity and difference of opinion have existed as to the metamorphosis of Aculeate Hymenoptera. Sir S. Saunders gives the following statement as to the larva of a wasp of the genus Pailiglossa} just before it assumes the pupal form : " The respective segments, which are very distinctly indi- cated, may be defined as follows : The five anterior, including the head, are compactly welded together, and incapable of separate action in the pseudo-pupa state ; the third, fourth, and fifth bearing a spiracle on either side. The thoracical region termi- nating here, the two anterior segments are assignable to the development of the imago head, as pointed out by Eatzeburg." This inference is not, however, correct. We have seen that in the perfect Insect of Petiolate Hymenoptera the first abdominal segment is fixed to the thorax, and Saunders' statement is in- teresting as showing that this assignment of parts already exists in the larva, but it in no way proves that the head of the imago is formed from the thorax of the larva. It has been stated that the larvae of the Aculeata have a different number of seg- nients according to the sex, but this also is incorrect. The difference that exists in the perfect Insects in this respect is due to the withdrawal of the terminal three segments to the interior in the female, and of two only in the male. The larva consists of fourteen segments, and we find this number distributed in the female perfect Insect as follows : one constitutes the head, four segments the thorax and propodeum, followed by six external seg- ments of the restricted abdomen, and three for the internal structures of the abdomen. This agrees with Forel's statement that in the ants the sting is placed in a chamber formed by three segments. The development of the sting of the common bee has been studied by Dewitz." It takes place in the last larval stage. Although nothing of the organ is visible externally in the adult larva, yet if such a larva be placed in spirit, there can be seen within the skin certain small appendages on the ventral surface of the penultimate and antepenultimate abdominal segments

1 Trans, cut. Soc. Loiwloii, 1873, p. 408. - Zcitschr. wiss. Zool. xxv. 1875, p. 184.

ACULEATA DEVELOPMENT

(Fig. 4, A) placed two on the one, four on the other ; these are the rudiments of the sting. In the course of development the terminal three segments are taken into the body, and the external pair of the appendages of the twelfth body segment (the ninth abdominal) become the sheaths of the. sting, and the middle pair become the director ; the pair of appendages on the eleventh segment give rise to the needles or spiculae. The sting -rudiments at an earlier stage (Fig. 4, C) are masses of hypodermis connected -with tracheae ; there is then but one pair on the twelfth segment, and this pair coalesce to form a single mass ; the rudiments g

of the pair that form the director are fi«. 4.-Deveiopment of sting of differentiated secondarily from the tiie bee: A and c, ventral ; B, primary pair of these masses of hypo- dermis. A good deal of discussion has taken place as to whether the component parts of the sting gonapophyses are to be considered as modifications of abdominal extremities {i.e. abdominal legs such as exist in Myriapods). Heymons is of opinion that this is not the case, but that the leg-rudiments and gonapophysal rudi- ments are quite distinct.^ The origin of the sting of Hymenoptera (and of the ovipositor of parasitic Hymenoptera) is very similar to that of the ovipositor of Lonosta (Vol. Y. p. 315 of this work), but there is much difference in the history of the development of the rudiments.

Dewitz has also traced the development of the thoracic appendages in Hymenoptera.^ Although no legs are visible in the adult larva, they really arise very early in the larval life from masses of hypodermis, and grow in the interior of the body, so that when the larva is adult the legs exist in a segmented though rudimentary condition in the interior of the body. Dewitz's study of the wing-development is less complete.

1 Morph. Jahrb. .xxiv. 1896, p. 192. ^ Zdtsclir. iviss. Zool. xx.x. 1878, p. 78.

side view. A, End of abdomen of adult larva : a, h, c, d, tbe last four segments, c being tbe eleventh body segment, 11 ; b bearing two pairs, and c one pair, of rudiments. E, Tip of abdomen of adult bee : 9, tbe ninth, d, tlie tenth body seg- ment. C, Rudiments in tiie early condition as seen within tlie body : c, first pair ; b, the second pair not yet divided into two pairs ; b'\ c', commence- ment of external growths from the internal projections. (After Dewitz.)

lO HVilENOPTERA

Four primary divisions of Aculeates are generally recognised, viz. Anthophila (Bees), Diploptera (Wasps), Fossores (Solitary Wasps), Heterogyna (Ants). Though apparently they are natural, it is impossible to define them by characters that are without some exceptions, especially in the case of the males. Ashmead has recently proposed ^ to divide the Fossores ; thus making five divisions as follows :

Body with more or less of the hairs on it plumose 1. Anthophila.

Hairs of body not plumose.

Prouotuni not reaching back to tegulae 2. Entomophila

[ = Fossores part] Pronotum reaching back to tegulae.

Petiole (articulating segment of abdomen) simple without scales or nodes. Front wings in repose with a fold making them narrow

3. Diploptera. Front wings not folded 4. Fossores [part].

Petiole with a scale or node (an irregular elevation on the upper side)

5. Heterogyna.

We shall here follow the usual method of treating all the fossorial wasps as forming a single group, uniting Ashmead's Entomophila and Fossores, as we think their separation is only valid for the purposes of a table ; the Pompilidae placed by the American savant in Fossores being as much allied to Entomo- phila as they are to the other Fossores with which Ashmead associates them.

Division I. Anthophila or Apidae Bees.

Some of the hairs of the body ]3lv,mose ; 'parti of the mouth elon- gated, sometimes to a great exteiit, so as to form a i^rotrusible apparatus, usually tubular vnth a very flexible tip. Basal joint of hind foot elongate. Xu wingless adult forms ; in some cases societies are formed, and then barren females called workers exist in great numbers, and carry on the industrial operations of the community. Food ahvcvys derived from, the vegetable kingdom, or from other Bees.

There are about 150 genera and 1500 species of bees at present known. Some call the division Mellifera instead of Anthophila. The term Apidae is used by some authorities to de- note all the bees, while others limit this term to one of the families

' Proc. ent. Soc. IVashincjton, iii. 1896, p. 334.

ANTHOPHILA BEES

I I

a rule, distinguished from

W,

Y^

or sub-divisions. The bees are, as other Hj'menoptera by tlie hairs, by tlie great development of the mouth parts to form a proboscis (usually, hut not correctly, called tongue), and by the modilication of the hind-legs ; but these distinctive characters are in some of the species exhibited in so minor a degree of perfection that it is not easy to recognise these primitive forms as Anthophila. A few general remarks on the three points mentioned will enable the student to better appreciate the importance of certain points we shall subsequently deal with. The bees are, as a rule, much more covered with hair than any other of the Hymenoptera. Saunders ^ states that he has examined the structure of the hairs in all the genera of British Aculeata, and that in none but the Anthophila do branched and plumose hairs occur. The func- tion of this kind of hairs is unknown; Saunders suggests-' that they may be instrumental in the gathering of pollen, but they occur in the parasitic bees as well as in the males, neither of which gather pollen. The variety of the positions they occupy on the body seems to offer but little support to the suggestion. Not all the hairs of the bee's body are plumose, some are simple, as shown in Fig. 5, A, and this is specially the case with the hairs that are placed at the edges of the dilated plates for carrying

pollen. In some forms there is an extensive system of simple hairs all over the body, and the "feathers" are distributed between these ; and we do not see any reason for assuming that the feathered are superior to the simple hairs for gathering and carrying pollen. Some bees, e.g. Prosopis, Ceratina, have very little hair on the body, but nevertheless some plumose hairs are always present even though they be very short:

1 Trans, ent. S'oc. 1878, p. 169.

n

Fig. 5. Hairs of Bees : A, simple hair from abdomen of Osmia ; B, spiral hair from abdomen of MnindiUe ; C, plumose hair from thorax of Meija- chile; D, from thorax of Andrenn dorsata ; E, from thorax of Proso^iis.

12

HYMENOPTERA

The hind-legs of bees are very largely used in the industrial occupations of these indefatigable creatures; one of their chief functions in the female being to act as receptacles for carrying pollen to the nest : they exhibit, however, considerable diversity. The parts most modified are the tibia and the iirst joint of the hind-foot. Pollen is carried by other parts of the body in many bees, and even the hind-leg itself is used in different ways for the

purpose : sometimes the outer face of the tibia is highly polished and its margins surrounded by hair, in which case pollen plates are said to exist (Fig. 6, A) ; sometimes the first joint of the tarsus is analogous to the tibia both in structure and function ; in other cases the hind- legs are thick and densety covered with hair that retains the pollen between the separate hairs. In this case the pollen is carried home in a dry state, while, in the species with pollen plates, the pollen is made into a mass of a clay-like consist- ence.^ The legs also assist in arrang- ing the pollen on the other parts of the body. The males do not carry

Pio 6.--A, Worker of the honey-bee ^ ^^^^ though their hind-legS

(^i^ismeta^tcft), with pollen plates J- ' o &

laden ; B, imsai portions of a are also highly modified, yet the

middle-leg (trochanter with part of ,„„j;-c„„ii „„„ ,i„ 4. -ii

eoxa and of femnr) with plumose 1^0"ilfi^atlOnS do not agree With

hairs and gr.nins of pollen ; c, one those of the female, and their func-

hair bearing poUen-cframs. ,- n ti-t, 1

tions are m all probability sexual. The parasitic bees also do not carry pollen, and exhibit another series of structures. The most interesting case in this series of modifications is that found in the genus Ajns, where the hind-leg of male, female, and worker are all different (Fig. 25); the limb in the worker being highly modified for industrial purposes. This case has been frequently referred to, in consequence of the difficulty that exists in connection with its heredity, for the

^ The mode of wetting tlie pollen is not clear. Wolff says it is done by an exu- dation from the tibia ; H. .'\Iiiller by admixture of nectar from the bee's mouth. The latter view is more probably correct.

BEES PROBOSCIS I 3

structure exists in neither of the parents. It is, in fact, a case of a very special adaptation appearing in the majority of the individuals of each generation, though nothing of the sort occurs in either parent.

The proboscis of the bee ^ is a very complex organ, and in its extremely developed forms exhibits a complication of details and a delicacy of structure that elicit the admiration of all who study it. In the lower bees, however, especially in Prosojns, it exists in a comparatively simple form (Fig. 9, B, 0), that differs but little from what is seen in some Vespidae or Fossores. The upper lip and the mandibles do not take any part in the formation of the bee's proboscis, which is consequently entirely made up from the lower lip and the maxillae, the former of these two organs ex- hibiting the greatest modifications. The proboscis is situate on the lower part of the head, and in repose is not visible ; a portion, and that by no means an inconsiderable one, of its modifications being for the purpose of its withdrawal and protection when not in use. For this object the under side of the head is provided with a very deep groove, in which the whole organ is, in bees with a short proboscis, withdrawn ; in the Apidae with a long pro- boscis this groove also exists, and the basal part of the proboscis is buried in it during repose, while the other parts of the elon- gate organ are doubled on the basal part, so that they extend backwards under the body, and the front end or tip of the tongue is, when in repose, its most posterior part.

For the extrasion of the proboscis there exists a special apparatus that conies into play after the mandibles