G. C. Crampton.
The Genitalia and Terminal Abdominal Structures of Male Neuroptera and Mecoptera with Notes on the Psocidae, Diptera and Trichoptera.
Psyche 25:47-58, 1918.

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19181 Crampton-Genitalia oj Male ~europteTa, etc. 47 THE GENITALIA AND TERMINAL ABDOMINAL STRUC- TURES OF MALE NEUROPTERA AND MECOPTERA
WITH NOTES ON THE PSOCIDAE, DIPTERA AND
TR1CHOPTERA.l
Since the Neuroptera form one of the most important groups for a phylogenetic study of the higher insectsy the discussion of the condition met with in them, and in the closely allied Mecoptera, is here offered as the basis of a' later, more detailed consideration of the genitalia of the Trichoptera, Diptera, and other higher forms which can be more profitably taken up in separate articles, and are therefore ody briefly referred to in the present paper. The homologies here proposed are based upon a more extensive con- sideration of the genitalia of the males of the lower insectsy pub- lished in the June, 1918 issue of the Bulletin of the Brooklyn Entomological Society, and forms one of the series of phylogenetic studies there listed.
Many of the accompanying rough sketches were made from miterial kindly loaned by Mr. Nathan Banksy to whom I am like- wise indebted for identifications of specimens, and for the loan of valuable literature dealing with the subject. Dr. R. J. Tillyard has also furnished me with a number of intensely interesting Neu- roptera for study, in addition to much valuable literature on Australian Neuroptera and Mecoptera. Since I have been largely dependent upon the-generosity of others for material in carrying on the present investigation, I would make use of this opportunity of acknowledging my deep obligation and expressing my very sincere gratitude to Mr. Banks and Dr. Tillyard for their ready and generous response to a request for aid in furnishing ma- terial and literature for such a study.
It is indeed surprising that so little has been published concern- ing the homologies of thl genitalia of male Neuroptera and Mecoptera, which are of the utmost importance for the correct inter- pretation of the parts in the higher forms. Since those who have referred to the genitalia of the groups in question have, for the 1 Contribution from the Entomolo~cal Lnborntory of the Masaachuaetta Agricultural College, Amherat, Mnaa.




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48 - Psyche [June
most part, contented themselves with merely describing the parts, without comparing them with other insects, the homologies here proposed must be regarded as purely provisional, until more inter- mediate stages can be obtained in order to determine what paths of development have been followed in arriving at the different types of genitalia here represented, or until suitable material can be obtained for dissections which cannot be carried out with dried, borrowed material, or from single specimensy upon which I have been largely dependent! On this accounty it is to be hoped that those who have specialized in these groups, and therefore have access to a wider range of forms and more favorable material, will carry out a more extensive study of the genitalia, in order to ar- rive at a definite conclusion concerning many of the points which a lack of suitable material has made it impossible to determine. It is quite generally conceded that the Sialid group should be rated among the most primitive representatives of the order Neur0ptera.l 1 have therefore selected Corydalis, Chauliodes and Neuronia (which are the most instructive representatives of the group, available to me) as the basis for a comparison with the higher forms here discussed. In these insects (Figs. 4, 10, and 15), the digestive canal opens through an anal tubercle called the tuberculum, anoppilla, or proctiger "ap." The two plates labeled "pay" one on either side of the tubercle "spy" were called par- aprocts in a previous discussion of the parts in Neuroptera (Cramp- ton, 1918), although 1 am not positive that they are the exact homologues of the paraprocts, or parapodial plates, of the Orth- optera and lower insects. In Corydalis (Fig. 15), the plate "pa" bears a pair of appendages "g," usually referred to as the superior . and inferior appendages of the gonopods. For the sake of brevity they may be termed the mrgortopod and mbgonopod. The upper appendage, or surgonopod (Fig. 15) is the larger of the twoy and appears to be the one to persist, when one of the two appendages is lost (as in Fig. 10, etc.).
Klapalek, 1903 (Bull. Int. Acad. Sci. BohGme), thinks that the gonopods of adult Trichoptera, etc. correspond to the "Nach- schiebern" (anal prolegs?) of the larva. The gonopods of Neu- 1 A ~tudy of the thoracic sclerites (which offer the most important characters for determining the relationships of insects) would indicate that the Neuroptera form a homogeneous group, which should not be further divided into "orders."



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mptem, Metoptera, etc.? are usually homologid with the s ~ I M ''~wo~u~s'' of the Ephemerida (Fig. 6, '' s "), but, IM was pointed out in a previous paper (Cmmpton, 1918), the struct~s l~bded "s" in Fig. 6 of the Ephemdd, are in reality dyli which e segmented (dwodyles) in some form, and are cornpod af a single segment in others. The segmented styli ( ~ s ~ y l e ~ ) labeled 'ts'y in Fig. 6 of the Ephemerid are borne on the plate "hy" ~ituated betow the male genitalia, and therefore mmot be homokqous with the gonopods "g" of Figs. lo, 15, etc., which are situated above the male genitalia, and are not borne on the plate "by," SQ that I have retained the tern "gonopods" for the strue- turn labeled " g," in F"i p. 10, 15, ek.? and have applied the desig- nation "&hmty1ed' to the segmented styli of the Ephemerida. The so-called '6mammiZlifmm ~ T W N ~ ~ of th ~LT," labeled '*pu" in Fig. I& and &&bed by Van der Weehle (Megaloptera, ColL Baron de %ly~ hnghamp) in C~&cd&, etc.; may pssi- bly be homologous with the s~eture called the titilhbr by BFUU- ner von Wathnwyl, 1876, in the O&opteray since the stmctwes in question are dtuated above the opening of the ejaculatory ducts in Cory&&, etc. (as is the w e in the Orthoptera). The structures labeled 4cpu" hi Figs. 4, 10, etc., on the other hand, are possibly homobgow with the so-called penis hooks, or 4cpenunci" of lower fom. For the sake of convenience, however, all the structures labeled "pu" are here referred to as i'~nh hooks," regardless of their position with reference to the oping of fie ejaculatory ducts. Ventral b the penh hooks 64pu" of Chaulidm (Fig. 10) is a b
cyhhicd column-like structure "eo" called the c~hmnu in a previous discusion of the parks in Newoptera {Crampbn, l918). Below this is the so-died genital waive "Iyv," which is homologous with the hypa~dGum or 8ubgenitul pla& of the lower insects. In the lower form, the plate "hy" of the mdes frequently be+m a pair of styli; but I have been unable ta hd these in any of the Nemptera or Mecopha thus far examined. The lobe-like structure situated above the plate "hy" and labeled "sl" in Fig. 15, may psi41 y be homologous with the so-called mbhK of lower insects (Crampbn, 1918).
In the Fsocid shown in Fig. 17, there is a mpaand pl& or qipoct ''sa'' sitmtd above the and opening, on either side of which is a parupo&d plate or pwapiwt "pa." 1 wouId iukrpxet



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the dlosity labeled "c" in Fig. 17, as the remains of the mrcus (which appears to be lmt, or vestigial in most Nmmptem), and the spine-like prows "g" as the homologue of the gonopod "g " of Chadwd~ (Fig. lo), &haugh I am not rn that these inter- pretations are mmect, until other material has been examined to determine thee points. The Psocid~. seem ta be as closdy re- lated to the Newoptera aa my of the lower hswtas and may be regarded aa amwtent betwen the Nemptma and the Embiid Plecopteron group, from which have also b~anched off the Imptern to which the Psouds are likewise closely related. It is impossibk to draw any ddmite condusiom concerning the ,
relationships of the different Xeumptemid insects from a study of the genitalia done; but the following poini~ of similarity of structure in the different groups may be noted. In the %lid group (Figs. 2,4,10, and IS), the hypadrium, or subgenital valve '' hy " is comparafively small, and the gonopods "g" with the para- pmcta "pa" me usuaI1y qresentd, although they adnot always well developed. The and tubercle ox proctiger "ap" is pmmt in most of this pup, while the s u p x ~ plate is mually wanting. Ifhone (Fig. 14) is considered as one of the most primitive representatives of the Neuroptera-PImipermia, and pwsents certain fatu~~s suggestive of the condition found in the Sialid pup. In the chid specimen of I t h lme fi@ {Fig. 14) there a p ~ d to be a somewhat shriveled ma1 tubercle or pmc- tiger "ap9' The structures hhld "g" h Fig. 14, me not very like the gonopods "g" of the Sialid group (Figs. 10 and 1.5); but resemble mmewht more closely the structures IakIed "g" in the Myrmelmnick {Fig. which have b a pmvisi~mll~ homologized with the gonopods, The pnis hooks "pu" of Ifhone (Fig, 14) me quite unlike those of the other fomg here shown, and me mvered by an a d d roof-Iike stmetme. The hypandrium or subpitd plate "hy" is well developed in Ib, unlike the condition occurring in the %lid pup. Poiyd~echot~ (Fig. 8), which is one of the PIanipemb, haa no well developed hypmdrim "hy," and a ~ ~ c t m labeled %'' in Fig. 8, may possibly mpresmt the columa %o" of the SiaIid group (Fig, 10). If this is corm$ the temimlia, or terminal abdominal stmetum of same PIanipennia are not dike those. of certain Sidids. In A r ~ a (Fig. I%), mother of the pup



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Planipmia, th~ hypandrium "hy yy is even larger &,an that of ~~ (Fig, 14, "hy") . In Xempba there k a large c o ~ ~ - like stmctwxe (Fig. 19, "HI '$1 which has been homologized with the c 0 1 ~ "co" of C11~adi.d~ (Fig. lo), and m additiony a smd ''epicoluma" labeled "p" has been developed. The mlum "m" of Fig. 12 beam two lobes at its apexs suggesting a biparhite origin fox this stmcture, and it is possible that it may mpment the united penis hooks " pu" (Figs. 4$ and 10) maer than the columa "CQ" of Fig. 10, I have provisiom~ly homologized the lateral pIates "pa" of Fi. 12, with the parapro& "pa" of Figs. 1'7 and 15; but 1 am not certain that this is the correct interpretation of these shctu~~. The structures labeled '4g" in Fig. 1% may not he the he gonopds, but have been pmvisiom~ly homologized with them.
Ngrnphm (Fig. 3) is regarded as one of the least mod%ed form related to the Mymeleoni&; but it has been very dficdt to interpret the pa& aright in this insect, and I am by no means cer- tain that the conchsions here reached are- the correct oms. Thk hypandrium "hy" is well developed in Xp~pIw (Fig. S), and the stmctures apparendy homo1ogous with the penis hooks, 1dxIed "pu" h Fig. 3, are very large and bear several "prongs." The stmeture designated "say' in the figure probably repmenis thd supraanal plate (epiproct), although it may possibly be homo1ogous with the anal tubercle instead. I have provisionally homologized the lobes "d?" of Fig. 3 with the copulatory lobes "ti" of the Mecopteron shorn in Fig. 18; but there k a possibility that they should ke homologized with the plates "pa" of Fig. 17 instead. The parts of ATymphe8 (Fig. 3) are disappointingly dike those of the A ~ ~ ~ p ~ d ~ (Fig. 1) and Myrmekonidie (Fig. 7) although the Ascaiaphid~ are very similar to the Myxmdmnid~ in hwing a dorsal plate "sa" (Figs. 1 and 71, which has been interpreted M the suranal plate or epiproct, and two elongate laha1 processes "g" provisionally homolo~zed with the gonopds. Madhpa (Fig. 5) resembles Nmqvtwa (Fig. 12) in having a well developed hypoproct "hy," within which is a slender structure labeled "CU" (Fig. 51, which may possibly be homologow with the structure hkprebd as the columa "co" in Fig. 12- The two plates "pa3' of Mantispa (Fig. 5) are possibly homologow with the plstes labeled "pa" in Fig. 12 of -Vemoptera.



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5% pwche [June
Raphidia (Fie. 16) does sot seem to be very like any of the other Neuroptera here figured so far aa its terminal structures are con- cerned. It has an arched dorsal plate "sa" which may represent the supraanal plate, or epiproct, beneath which are two processes 'g," provisionally homologized with the gonopods "g" of Fig. 10, etc. The two penis hooks "pu" of RwpMdia. (Fig. 16) are apparently homologous with the structures labeled "pu" in Fig. 5 of Mantisya, and the median hook "mu" of Fig. 16, is possibly homologous with the median hook " mu'' of Fig. 5, although I am somewhat at a loss to account for the homologies of the structure 'mil" of Figs. 5 and 16, in other forms. The Coniopterygidse (Fig. Il) are too small and highly specialized for one to be able to make very much out of a study of theirparts. The hypandrium "hy," of Fig. 11, is comparatively well developed, and the structures labeled "pu" appear to represent the penis hooks "pu" of the other Neuroptera. The terminal structures of the Coniopterygidse appear to resemble those of the PIanipennia, as much as any other Neuroptera.
Turning next to the consideration of the genitalia and terminalia of the Mecoptera, we find two types represented, namely, those with forceps-like gonopods (e. g., Figs. 24, SO, 23, 27, and 28) which are of extreme length, in Merope (Fig. 24 "g"), and a second type represented by the Biffacus-grwp (Figs. 18 and 92) in which the gonopods are not developed in the form of forceps-like structures. In Vol. 27, page 898 of the ~ntarn0!ogical News for July, 1916, I suggested that the Merope type of Mecoptera represented a sub- order called the 4'Promecoptera,'p in which the wings present a very primitive venation, the head is not greatly elongated, etc. Mewe, however, is quite closely allied to the other members of the Fanwpa-group, and should be included in it, so that there are but two principal groups of living Mecoptern (the Bittam- type and the Panmpa-type) and these two might be considered as representing two suborders of the Mecoptera, although they are more probably of merely superfamily rank. Tillyard, 1917 (Proc. Linn. Soc. N. S. Wales, 49, p. 1881, applies the term Pro- tomecoptera to a new order of fossil insects which in certain re- spects resemble the ancestors of living Mecoptera. Although I feel certain that such forms exist, I have been unable to find any Neuroptera in which the gonopods are in the form of



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resemble Nymphs (Fig. 3) as much as any Neuroptera, in spect to its terminal structures; and the median terminal ap- T Ì 35 fin- in *Art 1-1. -11. 1 t . ... _*iL r-----D- -- --
- . - - - - -. - - . . > - -. - - - -. . - - - - - - - - . . - 0---
the snpraanal plate (epiproct) or with the anal tubercle (proctiger), is apparently the homologue of the median terminal structure labeled "sa" in Fig. 3 of Nympiies. The copulatory claspere " cl of Bittacua (Figs. 18 and 22) are possibly represented by the t actually homologous with, the copulatory claspers. "cl," of e Phasmid shown in Fig, 9, and doubtless had a similar origin. spers "cl " are very large in Biftacus stngosus (Fig. 18) ; much smaller in BiHocus piZWOTnis (Fig. 92). Correlated greater development of the claspers "el" of Sittmnt~ gom (Fig. 18), there is a greater development of the appendages eled "c*' (which are provisionally homologized 'with the cerci) an in Bittams pihornis (Fig. 22), although in the latter insect, median appendage " sa " is proportionately somewhat larger an that of B. sfrigosus (Fig. 18). In both insects shown in Figs. and 22, there occurs a pair of closely approximated hooks la- beled " pu," provisionally homologized with the penis books. Between them there projects a spiral thread or spirofilum "sf," wound like a watch spring. It is possible that this spiral thread "pu" (Figs. 18 and $22) is a pair of appendages labeled "g?" which hay represent the gonopods of the other Mecoptera, al- of the most noticeable features is the lack of development of the claspers "PI" in the former group. On the other hand, the gono- pods "g" are greatly developed in the Panorpa-group (Figs.$24



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54 Psyche [June
"g?" in Fig. 18, since it may correspond to the structure labeled "pu," instead; but I have provisionally adopted the interpreta- tion indicated by the labeling. In most of the Panorpa-group there are one or two pairs of dorsal valves (dorsovalvse), "dv" of Figs. 21, 23, 24, etc., and a pair of ventral valvse (ventrovalvse) , "vv" of Figs. 23, 26, etc., and it is possible that certain of these valvse may represent the penis hooks of Neuroptera, etc. The anal tubercle "ap" of Fig. 21, bears at its base a pair of appendages " c " whose location suggests that they are homologous with the so-called cerci "c" at the base of the median terminal structure "sa" of Figs. 18 and 22. On this account, I would consider the structure "ap" of Fig. 21 as homologous with the structure "sa?" of Figs. 18 and 22, although I am not certain whether the structure labeled "sa?" in Figs. 18 and 22 is the epi- proct "sa," or the proctiger "ap," of other insects. Tillyard describes a pair of segmented cerci in Nannochorista (Fig. 28, " c "), which appear to be homologous with the structures labeled "c" in Figs. 21, 23, etc., and on this account I have interpreted the latter structures as the cerci. I am not certain of the correctness of my interpretation of the structures labeled "c," as the cerci, and the structures labeled "dv," as the dorsal valvse, in Fig. 24 of Merope; but have provisionally adopted this method of homol- ogizing them. The projecting ventral process "co" of Fig. 26, may be homologous with the columna, and if the latter is repre- sented by the coiled filament "sf" of Figs. 18 and 22, the structure labeled "co" in Fig. 26 is doubtless to be homologized with the coiled filament "sf" also.
The phallus "pe" is large and prominent in Boreus (Fig. 20), and the hypandrium "hy" is well developed in this insect. In Panorpodes (Fig. 27) the structure which is here interpreted as the hypandrium "hy" shows a marked tendency to become long drawn out and furcate, although the cleft at its apex is not very deep. In the Panorpid shown in Fig. 26, however, the hypandrium "hy" is deeply cleft, and the two arms of the fork are compara- tively long and narrow. The character of the hypandrium fork, the valvse, etc., should be as valuable features for the purpose of classification as any structures, and it is surprising that they are not more employed in taxonomic keys.
The gonopods "g" of the Mecoptera here figured are composed of two segments. The basal one "pa?" of Fig. 23 may possibly



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19181 Crampton-Genitalia of Male Neuroptera, etc. 55 correspond to the paraprocts "pa" of the Neuroptera (Fig. 15, "pa"), although the elongate basal segment " g " of the gonopod of the very primitive Mecopteron Merope (Fig. 24) is nothing like the paraprocts in character, and this casts some doubt upon the supposition that the basal segment of the gonopods of the Mecoptera in general corresponds to the paraproct. As was mentioned above, it is very strange that no Neuroptera have been described in which the gonopods are of the type repre- sented in Merope (Fig. 24, "g") which isa very primitive Mecop- teron in many respects, since the tendency toward the develop- ment of forceps-like gonopods occurs in many Mecoptera, Dip- tera, Trichoptera and other forms descended from Neuropteron- like forebears. The gonopods "g" of such Mecoptera as Merope (Fig. 24) are apparently the prototypes of those found in certain Diptera such as the Chironomid Clunio (Fig. 25, "g"). The oc- currence of this type of gonopod in the Diptera lends further weight to the view that the Mecoptera are very like the ancestors of the Diptera.
Some Trichoptera have well developed gonopods, such as those of Philopotamus (Fig. 30, "g"), as might be expected from other evidence that the Trichoptera are rather closely related to the gonopod-bearing Mecoptera, both groups having apparently de- cended from Neuropteroid ancestors. The structures labeled "cl" occurring on either side of the supraanal plate "sa" of Philopotamus (Figs. 30 and 13) resemble cerci in some respects; but have been provisionally homologized with the clasper lobes ' cl" of other forms. Klapalek, 1903, refers to similar appendages in the Trichoptera as the " appendices prseanales." As far as the relationships of the orders here discussed are con- cerned, I would maintain that the Neuroptera, Mecoptera, Dip- tera, Trichoptera and Lepidoptera constitute a superorder, the Panneuroptera, certain of whose members exhibit a tendency to- ward the formation of hairs or scales on the wings (e. g., certain Myrmeleonids, a few Panorpids, the Psychodid Diptera, etc., in addition to many Trichoptera, and most Lepidoptera), and in most of which the
meso-thoracic coxse, at least, are divided into a veracoxa and merocoxa (see Crampton and Hasey, 1915, "The Basal Segments of the Leg in Insects;" Zo6l. Jahrb., Abt. Anat., 39, p. I-), the mesothoracic and meta-thoracic coxse are usually



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56 ' Psyche [June
approximated, there is usually a sternal fulcrum of the coxa (Crampton and Hasey, 1. c.), and other characters showing that they have much in common.
I would group the Psocidse, Thysanoptera, Mallophaga, Ano- plura (Pediculidse) , Hemiptera and Homoptera in another su- perorder, the Panhornoptera, but by so doing, I would not minimize the close relationship of the Psocids to the Neuroptera, and the close approach of the Hemipteroid lines of development to those of the Mecoptera and Diptera. The Hymenoptera are closely allied to both the Psocidse and the Neuroptera, and I have been unable as yet to determine in which of the two superorders they should be placed.
In connection with the discussion of the interrelationships of the orders of insects, it may be of some interest to note that it would appear that in the interesting little Crustacean Bathynella we have a form very like the common ancestors of the Insecta and "&Kyriopoda" (sensu lato). Bathynella belongs to a very ancient group of Crustacea, and the number of segments com- posing its body, the character of its appendages (which are lack- ing on the last segments), etc., are all in accord with the view that it is very like the ancestors of the Proturan insects. Bathynella is also very like the probable ancestors of the Symphyla-Pauro- poda, a group which has departed but little from the condition characteristic of the ancestors of the "Myropoda" as a whole. The following articles treat only of the Neuroptera and Mecop- tera.
Bibliographies of works on Trichoptera, Diptera, etc., will be given in articles dealing with the genitalia of these groups. 1914. CHAMPION. Revision of the Mexican and C. Amer. Chauliognathida?, Based on the Genital Armature of the Males. Trans. Ent. Soc., London, 1914, p. 128-. 1918. CRAMPTON. Phylogenetic Study of. Genitalia of Males of Lower Insects. Bull. Boooklyn Ent. Soc.
ESBEN PETERSON. Monograph of the Mecoptera. Coll. Zotil., Baron ~el~s-~&eham~s.
1895. FELT. Scorpion-flies. 10th Rpt. N. Y. State Entomolo- gist, p. 463-.




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Crampton-Genitalia of Male Neuroptera, etc. 57
KLAPALEK. Bittacus tipularius, Beitr . z. Morphologie der Genitalsegmente. Prag Cas. Ceske Spol. Ent., Jg. 7, p. 114-.
LECAZE DURTHIERS. Rech. s. 1'Armure Gknitale femelle d. Insectes Neuropteres. Ann. Sci. Nat. ser. 3, 19, p. 25-. MCLACHLAN. Monograph of the British Neuroptera Planipennia. Trans. Ent. Soc., London, 68, p. 20%. MIYAKE. Studies on the Mecoptera of Japan. Jour. Coll. Agr. Imp. Univ. Tokyo, 4, p. 265-. STITZ. Z. K. d. Genitalapparates der Panorpaten. Zool. Jahrb., Abt. Anat., 26, p. 537- .
STITZ. Z. K. d. Genitalapparates der Neuropteren? Ibid., 27, p. 377- .
VAN DEB WEELE. Megaloptera. Coll. Zool., Baron Selys-Longchamps .
See also articles by Banks, Tillyard, and other systematic articles on Neuroptera and Fecoptera.
ap =Anal tubercle, anopap-
pilla, or proctiger.
c = Cerci, or vestiges of cerci.
cl = Copulatory lobes, or copu-
lobi.
co = Colurnna.
dv = Dorsal valve, or dorso-
valve.
pa = Parapodial plates, or para-
procts.
pe = Phallus.
pr = Preepiproct .
pu = Penis hooks, or penunci.
s =Jointed styli, or arthrostyles.
ep = Epicolumna.
f = Pendent filaments.
g = Gonopods, or their homo-
logues.
hy = Subgenital valve, or hy-
pandrium.
mu=Median hook, or medi-
uncus.
sa = Supraanal plate, or epi-
proct .
sf = Spiral filament, or spiro-
filum.
sl = Sublaminse.
t =Terminal filament, or telo-