psyche - core

PSYCHEVol. 79 March-June, 1972 No. I-2

EGGS AND RAPAGULA OF ULULODE8 ANDztSGztLOPTYNX (NEUROPTERA: ASCALAPHIDAE):

A COMPARATIVE STUDY*

BY CHARLES S. HENRYBiological Laboratories

Harvard University, Cambridge, Mass. o2138I. INTRODUCTION

Ascalaphidae is a fairly large amily o planipennian Neuroptera,encompassing perhaps 300 species in 65 genera, yet relatively littleis known of the biology ot its various representatives. Althoughseveral systematic monographs concerned exclusively with the familyhave been published (Lefebvre, I842; Rambur, I842; McLachlan,I87I; Van der Weele, I9O8; Navels, I913), attempts to discern thetrue phylogenetic relationships among the various genera and othertaxa must necessarily await studies o lie-history and behavior. Int:act, definite larva-adult associations are lacking for a great majorityof ascalaphid species. Larvae have been reliably identified only (orthe genera ztscalaphus Fabricius, Helicomitus McLachlan, Pseudo-ptynx Weele, Suhpalacsa Lefebvre, and Ululodes Currie, all be-longing to the "split-eyed" subfamily Ascalaphinae; o the "entire-eyed" subfamily Neuroptynginae, only zlscaloptynx Banks has beenassociated with a larval type (MacLeod, 97o: p. 55).

I have succeeded in rearing an additional species o Ululodes t:romegg to adult: Ululodes mexicana (McLachlan), common in northernMexico and southern Arizona and New Mexico. I have also beenable to compare the (orm and habits of the various lie stages ofthis species with those ot a sympatric neuroptyngine species, ./lscalo-ptynx furciger (McLa.chlan). The identity of this last-named speciesis inferred, but based upon various types of evidence: (I) third-instar larvae, raised from field-collected eggs, were positively identi-fied by Dr. Ellis G. MacLeod (University of Illinois) as those ofAscaloptynx; (2) the only species of the genus Ascaloptynx--or,for that matter, of subfamily Neuroptynginaemever taken at the

*Manuscript received by the editor August 1, 1972.

2 Psyche [March-June

collecting sites in question is [urciger; (3) males and females odscaloptynx [urciger were captured in fair abundance in the sameareas and at the same time of year that eggs and young larvae werecollected; (4) dissections of gravid d. [urciger emales revealedeggs and egg-attendants (see text) that were in every respect identicalto field-laid eggs that yielded dscaloptynx larvae.The first student of ascalaphid life-history was. the Reverend L.

Guilding, whose 827 account of the vario,us life stages Ululodesmacleayana (Guilding)* rom St. Vincent’s Island in the WestIndies remains one o.f the best such studies, ever published. In de-scribing the eggs o.f this species, he noted the presence of curiousrod-shaped structures encircling the twiff beneath the. egg-mass. Hecalled these egg-attendants "repagula,"** meaning "barriers," be-cause he believed that they prevented ants and other predators fromapproaching and destroying the eggs and newly hatched larvae; con-versely, he felt that the repagula discouraged the larvae from leavingtheir twig "until they have acquired strength to resist... [their]enemies." McClendon (9o) also noted repagula accompanyingthe eggs of Ululodes hyalina (Latreille) [believed by MacLeod(964) to be Ululodes senex (Burmeister) ] rom Texas; he con-firmed Guilding’s description of these structures and co.ncluded fromhis dissections of gravid female ascalaphids (unfortunately unillus-trated) that certain ovarioles ("tubercles") were specialized for theproduction of repagula. Thus it was shown that repagula were inact abortive eggs. Seventy years later, New (1971), apparentlyoverlooking the papers of Guilding and McClendon, re-iotroducedthe concept of ovariolar dimorphism in his cursory study o the eggsand repagula of eight species of Ascalaphidae rom central Brazil.New’s paper is important, nonetheless, for two reasons: first, itproved that repagula-formation is not unique to the genus Ululodesbut is also found in the closely-allied genera Colobopterus Rambur,Ascalorphne Banks and Cordulecerus Rambur, and in the neuro-ptyngine genera Byas Rambur and Episperches Gerstaecker secondly,it sug,ested that the repagula of neuroptyngine species are funda-mentally different in orm from those of ascalaphine species theformer type more nearly resembling fertile eggs than the latter type.The functional significance of repagula has not been investigated.

Most authors (Irnms, 1957, for example) have. accepted Guilding’s"ant guard" view. New (1971) intimates that repagula and eggs

*Guilding’s name for this species was dscalaphus macIeayanus.**singular repagulum.

1972] Henry Ululodes and AscMoptynx 3

alike o Ululodes were carried off by ants in Brazil, but admitsthat more controlled experimentation is needed to assess the effectsof the repagula on egg or larval survival. Through my studies othe lie-histories of Ululodes mexicana and Ascaloptynx furciger,I have been placed in a unique position to verify or disprove experi-mentally the ant-guard hypothesis, as it applies to these representa-tive species of two taxonomically distant genera. Especially importantis the fact that Ululodes is an ascalaphine genus while Ascaloptynxis a neuroptyngine one, thus encouraging direct comparison o theunctional signicance of the morphologically disparate repagula char-acteristic of the members of these subfamilies. In the remainder o thispaper, I intend (I) to describe the eggs and repagula o Ululodesmexicana and Ascaloptynx furciger, (2) to outline the proceduresand results of several simple experiments undertaken to test theprotective importance of the repagula o bo,th species, and (3) todiscuss the unctional significance o the ascalaphine type of egg andrepagula as compared to that of the neuroptyngine type.

II. ACKNOWLEDGEMENTSSpecial thanks are extended to Professor Frank /I. Carpenter,

my advisor and friend for the past five years. All aspects o thework in this paper draw heavily rom his awesome knowledge oinsect behavior, morphology, evolution and taxonomy, especially othe order Neuroptera. I am also in his debt or his help in guidingthis study into publishable orm.My wie, Nancy FitzGerald, should also be cited as a primary

source of inspiration for this project. Her shrewd suggestions andsharp observations in the ield are apparent to. me. again and againas ! review my notebooks nd ind her influence in their pages.

In addition, warm thanks are extended to: Pro.essor Ellis G.MacLeod (University o.f Illinois), for his generous willingnessto transmit his intimate knowledge of the habits of all sorts ofneuropterous insects to a neophyte like myself, and for confirmingthe identity of Ascaloptynx larvae; Professo.r Edward O. Wilson(Harvard Biological Laboratories), for enthusiastically supportingmy research effort and for determining the genera, and species of antsused in the ant-guard experiments; Mr. Vincent Roth of the South-western Research Station, for his assistance with my field work inArizona; Dr. Lauren Anderson (University of California at River-side), for his advice on securing newly-hatched ascalaphids; andMr. Robert E. Silberglied (Harvard Biological Laboratories), t;orhis photographic help and biological acumen.

Psyche [March-June

Figure 1. Typical sites for oviposition, Ululodes mexicana (l-a) andAscaloptynx [urciger (l-b).

Year-round financial support for my studies was for three yearsprovided by the National Science Foundation, in the form of aPre-Doctoral Fellowship (September, 968 to September, I97). Afinal fourth year of research was completed with the aid of a Rich-mond Fellowship (97I-’72) offered through Harvard’s Departmentof Biology. Unusual expenses associated with travel to the field andwith publication of this paper were generously advanced by theCommittee on Evolutionary Biology, Harvard University (NSFGrant GB 279, Reed Rollins, Harvard University, PrincipalInvestigator).

III. METHODS AND MATERIALSEggs o both Ululodes mexicana and Ascaloptynx furciger were

collected during August and September in the southeastern part oArizona, within a 25-mile radius o the Southwestern ResearchStation o the American Museum o Natural History (SWRS).All egg-masses, 25 of Ululodes and 35 of Ascaloptynx, were takenon shrubs in the arroyos and canyons of the Chiricahua and PeloncilloMountains, at elevations of 4700 to 570o feet (5oo-8oo meters).Several egg-masses were left in situ and visited twice daily; others

1972] Henry Ululodes and Ascalottynx 5

were placed twigs and all in 2.5 cm X 9.0 cm glass screw-top vialsand transported carefully to the research station laboratory. There,the egg-bearing twigs were taped in their "natural" positions, coveredwith large glass jars for observation and situated in a southwestwindow shielded by heavy curtains orm the vicissitudes of indoorartificial light. Complete records from oviposition through hatchingto descent of larvae were obtained for seven egg-masses of Ululodeg

and eight of Ascaloptynx. Additional egg-clumps of both species ofAscalaphidae were exposed to several natural and exotic insect preda-tors (mostly ants) under various experimental conditions, to ascertainthe effectiveness of the repagula. In each experiment, for eachascalaphid species, two normal egg-masses and one egg-mass strippedof its repagula were mounted (on their respective twigs) in thevicinity of foraging ants, in such a manner that the bottom-mostegg of each clump was positioned 16 cm above the ground. Thebehavioral details and success of each foray of an ant (or otherinsect) up an egg-bearing twig were carefully noted. Similarexperiments were carried out using hatched egg-masses, prior todescent of the larvae from their twigs.

Closer observation and dissection of eggs, repagula, and gravidfemale ascalaphids were undertaken beneath a Wild M5 stereoscopicdissecting ’scope outfitted with an integral camera lucida attachment;most of the illustrations included with this paper were renderedwith the aid of this precision imaging device. Extremely smallspecimens and structures were treated with xylene and mounted inDamar on depression-slides and observed at higher magnificationusing a Bausch and Lomb stereoscopic compound microscope withone ocular fitted with a IO IO micrometer grid to insure accuratedrawings.

IV. DESCRIPTIONS OF Eos AND REPAGULAA. Ululodes mexicana McLachlanAdults of U. mexicana appear in large numbers in southeastern

Arizona at the beginning of August, and remain abundant until thetime of first frost mid or late October. Males apparently die offby early September, while females, which individually may live threemonths or more under laboratory conditions, begin laying eggs atthe start of the dry season in September and continue ovipositing farinto October. Females display great selectivity in their choice ofsites for oviposition, but are quite unselective of the particularspecies of plant: eggs are laid probably at dawn on the thin periph-eral dead twigs of any two or four foot deciduous shrub growing

Psyche [March-June

1972] Henry Ululodes and dscaloptynx 7

on totally exposed, south-facing embankments o dry arroyos andcanyons (/gure I-a). The insects always seem to choose inclinedrather than vertical twigs, and seek out the downhill sides o thebushes in preference to any other spots; this latter choice givesthe hatched larvae an unobstructed all of 50 to 85 cm (I8-3oinches) to the crumbling rocky substrate below.

U. mexicana eggs are laid on the undersides and towards the tipsot: their twigs, in two long interdigitating rows together totalling30 to as many as 52 eggs (figure 2). Each freshly laid egg is lightgrey or cream-grey in color and oblong in shape, averaging .6 to2.o mm in length and o.8 to .o mm in diameter; all the eggs ina given egg-mass will be of roughly equivalent size, but differentegg-masses will vary considerably in their egg dimensions. The eggsare laid on end, inclined slightly toward the tip of the twig. Theyare attached to the substrate by a shiny reddish-brown glue. Eachegg possesses two identical, pale micropyles, about o. mm in diameter,axially located one at each end; high power examination revealsthe micropyle to be saucer-shaped, constructed of approximatelytwenty ribs or channels radiating from a central depression (figure3-A). Except for the micropylar sculpturing and a very slightgraininess to the balance of the egg surface, the Ululodes choriondisplays no elaborate fine-stucture.

Figure 3. Micropyles of Ululodes mexica’na (A) and ./lscaloptynxfurciger (B) eggs.


Three to our days ater oviposition there appears a diffuse whitishline nearly girdling the egg a short distance rom its distal pole(figure 4)- This line circumscribes an arc o 27o degrees and marksthe line o weakness along which the egg will split as the larvaemerges; the extent o the weakened area and the positioning oeach egg at the time o laying assures that the "cap" o each eggwill remain attached to the main egg body by a "hinge" and willflip toward the midline o the egg-mass at the time o hatching. Itcan be seen (figure 4) that the developing embryo conforms to nostrict rule o position within the egg except to have its head endtoward the egg’s distal pole..A ew days prior to hatching, thewhitish outline o the embryo disappears and the sides o the eggcave in slightly; the egg progressively darkens to a slate-grey colorand hatches on the iteenth or sixteenth day ater oviposition.The repagula o Ululodes mexicana do not resemble the eggs at

all. They are rod- or club-shaped structures, reddish-brown andshiny in apperance, surrounding the twig bristle-like (ive to tenmillimeters below the egg-mass ((igure 2). Sometimes they arearranged in a series o neat rings but more usually are ratherirregularly placed. Each repagulum is approximately two-thirds thelength o a normal egg, measuring 1.2 to .4 mm in length ando.25 to o.3o mm at its widest point; it appears to lack any vestigeo a micropyle, despite its ovariolar origin. It is characterized by asmall, round, light-colored basal swelling and a larger, oblong,darker distal swelling, joined by a thin translucent stem ((igure5-B). The over-all reddish hue is apparently imparted by the. shinyfluid coating each repagulum. This non-sticky fluid should not beconused with the hard brownish glue that secures both eggs andrepagula to the stem: it neither hardens upon nor evaporates romthe repagulum surface or at least three to our weeks ater ovi-position. Long ater the true eggs have hatched, these strangebarriers gradually collapse, their surfaces choked with debris.

Apparently the repagula are extruded rom the emale’s bodya(ter she has deposited her eggs, since in laboratory situations repagulaare oten ound glued randomly to the surfaces o the eggs.. Thusit would seem that the Ululodes emale oviposits progressively romthe tip o the twig towards its base, with her head oriented down-ward; such a view agrees with what we know o the standard rest-posture o( Ascalaphidae. Typically, our o the twelve ovarioles ineach o the emale’s ovaries are modified for the production orepagula ((igure 6). However, the insect is nevertheless capable

1972] Henry Ululodes and Ascaloptynx

,,, 1 mmFigure 4. Detail of eggs of Ululodes mexicana, three to four days old.

of depositing as many as or more repagula than eggs at any giventime, since each modified ovariole can store many more "mature"repagula than a normal ovariole can eggs. Stored repagula showno trace of the reddish color characteristic of oviposited repagula,suggesting that the red fluid is secreted by some accessory gland atthe time of deposition.

B. dscaloltynx furciger (McLachlan)Adults of Ascaloptynx furciger are active earlier in the summer

than U. mexicana, seemingly being most abundant in southeasternArizona during the rainy season, from early June to early September.As in Ululodes, males become less common in the latter half of thistime period. Eggs are in greatest evidence during August, withchalcidoid parasitism destro.ying 95 percent of the egg-masses de-posited after September . Again like Ululodes, ovipositingAscaloltynx females are extraordinarily habitat specific, yet displaylittle preference for particular plant species: eggs are laid on thethin terminal dead twigs of any one to two oot perennial or grassclump growing in protected semi-shaded locales in the foothills ofthe mountains, where rainfall is relatively great and scrub oak(Quercus emoryi and O. arizonicus) and juniper (Junilerus de-peana) abound. In contrast to Ululodes, vertically oriented twigs

io Psyche [March-June

Figure 5. Comparison of the repagula (r) and eggs (e) of Ascaloptynx]urciger (A) and Ululodes mexicana (B).

or grass-stems are always selected (figures -b); the substrate be-neath the egg-clumps is nearly always densely strewn with dry oaklitter.

Ascaloptynx [urciger eggs are laid in dense clumps completelysurrounding their twigs, near the tips of the stems, perhaps 22 to

55 cm (8 to 8 inches) from the ground. The structure of the egg-mass suggests that it might consist of several long, parallel, tightly-spiraling rows of eggs. These clumps typically include 35 to 45ovoid eggs, each one glued by its mid-section to its twig with itslonger dimension oriented nearly horizontally (figure 7). Thefreshly laid Ascaloltynx egg is bright yellow-ochre in color, aver-aging 2. to 2.4 mm in length and .2 to .3 mm in diameter; it isthus larger and proportionally less elongate than that of Ululodes.It possesses two axially located micropyles, about o.5 mm indiameter, identical to those of Ululodes in all respects except size(figure 3-B). The chorion of the egg displays no sculpturing.As in Ululodes, several days after oviposition a whitish girdling

line appears at the "head" end of the egg, outlining the extent ofthe egg cap (figure 8). In Ascaloptynx, positioning of the eggs onthe twig assures that every egg cap will flip downward on its hinge;

1972] [enry Ululodes and dscaloptynx

in act, the cephalic (cap) pole of each egg is slightly lower thanits opposite pole and related to the cephalic poles of its neighborsin such a way that no larva interferes with another during hatching.It is of interest that in Ascalopt:nx the whitish outline of thedeveloping embryo always appears on the dorsal surface of the egg.As in Ululodes, this outline disappears as the egg gradually darkensto a muddy brownish-yellow color and acquires a semi-collapsedappearance several days before hatching; eclosion occurs a minimumof 4 days after oviposition.The repagula of Ascaloptynx furciger appear to be miniaturized

versions of fertile eggs" each is identical to a full-sized egg in color,proportion, micropyla.r structure, and orientatation (figure 5-2t).Typically, a repagulum in this species measures 1.3 to I.4 mm by0.65 to o.7o mm; it has no fluid of any kind on its surface. In allegg-masses examined, repa.gula occurred in a small group immediatelybelow (and continuous with) the main egg clump, and in a largergroup about IO cm further down the twig; frequently, one or twoadditional, smaller masses of repagula would be present, spacedvarying distances below the largest clump (figure 7, "Ra"). Usuallythe masses of repagula surround the twig in the same manner asfertile eggs, but occasionally, especially on large stems, the repagulaare deposited in an obvious spiral pattern. Dissections of Ascaloptynxemales reveal an arrangement of specialized ovarioles similar to thatin Ululodes; however, poor preservation prevented reliable con-clusions as to numbers o.f ovarioles present and modified. Field-collected egg-masses always exhibit slightly higher numbers of fertileeggs than of repagula.

V, PREDATION EXPERIMENTSExperimental exposure of the eggs and repagula of both ascalaphid

species involved three situations () natural predation by Dory-myrmex pyramicus, Formica sp. and Pogonomyrmex sp. at the siteof the Southwestern Research Station (54oo feet); (2) naturalpredation by Pheidole sp., Paratrechina sp., Crematogaster sp.,Dorymyrmex pyramicus, and Formica sp. at a typical egg-collectingsite near Crystal Cave in the Chiricahua Mountains (5700 feet);and (3) artificially-induced predation by Monomorium sp. intro-duced to the Harvard Biological Laboratories (Cambridge, Massa-chusetts) from Brazil.

A. Ululodes mexicanaIn all experimental situations, Ululodes mexicana eggs protected


Figure 6. Ventral dissection of gravid female Ululodes mexicana, show-ing normal ovarioles (Oe) and those specially modified for the productionof repagula (Or).

by their repagula were unassailable by any species o ant, evenlarge (> 5mm) Formica sp. (see Table I); on the other hand,unprotected eggs were quickly discovered and carried off by all antspecies tested. Ants ascending the twigs and touching the repagulawith their antennae would immediately and violently withdraw,occasionally talling to the ground. An intense period o antenna.-cleaning, lasting rom 5 to 6o seconds, always ollowed such con-tact. Experiments under laboratory conditions using the exoticBrazilian ant Monomorium sp. (2 mm long) indicated that con-tact with one repagulum alone was sufficient to discourage an antxCrom ascending the twig. Artificial "repagula" made trom short

Henry Ululodes and Ascaloltynx


threads coated with mineral oil were partially effective as guardsagainst Monomorium, but induced in the ant simple avoidancerather than active withdrawal; a single artificial "repagulum"proved totally inadequate for protecting an egg-clump.Our field data is most complete and convincing for the ground-

and low-bush-foraging species Dorymyrmex pyramicus (3 to 4 mmlong). This is ortunate in the sense that pyramicus appears to bequite abundant in areas normally chosen by Ululodes tor ovi-position; however, Formica sp., Crematogaster sp., and severalother undetermined species ot bush-foraging ants are also potentiallyimportant egg predators and should be more extensively tested.The ant-fences ot Ululodes are equally effective against ant

predators atter hatching has occurred and the larvae are sitting ina group on their eggshells; in fact, repagula remain full and fluid-covered even three weeks after eclosion, while the larvae apparentlyrest .on the twigs for no more than ten days. Insect predators, orother disturbances introduced artificially elicit no defensive reactionstro.m the larvae during their gregarious phase. Instead, upset larvaesimply drop to the ground, suspended at first on silken threads, twoto three centimeters long.

B. Ascaloptynx furcigerThe repagula of Ascaloptynx furciger seemingly serve no dis-

cernable protective function. No species o ant tested (see Table I)displayed any pronounced or consistent negative reaction to therepagula. However, despite the accessibility o the main egg-massto ant predators, no eggs were broken or carried off in the course othese experiments. Ants were observed to probe and bite the eggs,but even robust specimens of Formica sp. and Pogonomyrmex sp.*seemed unable to pierce the shells. Repagula, too, for the most partremained unharmed; in the one case where a Formica sp. crusheda repagulum in its jaws, the ant showed no further interest in eatingthe structure or retrieving it for the colony. Admittedly, our sample-sizes are quite small and incomplete so far as ant species are con-cerned, but the contrast between the reactions of ants to Ululodeseggs and repagula compared with their reactions to. those o.t zlsca-loptynx is striking.The repagula of recently hatched dscaloptynx egg-masses always

appear to be shriveled or collapsed, almost as if the abortive eggshad been consumed by predators. Observations of the activities of

*Pogonomyrmex is not normally a twig-forager" the egg-mass was throwndirectly on to the nest mound, at midday.

1972] Henry Ululodes and Ascalo#tynx I5

Figure 7. Egg-mass of .4scalotynx [urciger. Fertile eggs (E) andrepagula (R1, R2, R,) in natural position.

16 Psyche [March-,lune

newly hatched larvae reveal that each dscaloptynx larva, withinthree hours of eclosion, descends the twig to the level of one oranother of the rings of repagula and feeds upon the contents of oneor two abortive eggs. The repagula are punctured by the sickle-shaped sucking mouthparts. No attempt is made to pierce fertile,unhatched eggs. Perhaps 75 percent of the brood obtain a firstmeal in this ashion; then, all return back up the twig and settlehead-downwards on and above the empty eggshells, overlapping likeshingles in such a manner that only the heads and jaws of individuallarvae are visible (figure 9). Unlike Ululodes larvae, Ascaloptynxlarvae actively defend themselves against predators during the sevento ten days spent on the twig" small invaders like fruit-flies ormidges will be captured and eaten by individual larvae., but largerpredators o,r ants induce a mass response consisting o head-rearingand rapid snapping of the jaws (figure 9). This reaction has beenseen to discourage wasps 5 ram) and caterpillars (25 ram) andpresumably would be effective against a wide array ot enemies;however, more intense and persistent disturbances cause the larvaeto drop rom their twigs to the ground. It should be noted herethat the first-i,nstar larvae o,f neither dscaloptynx nor Ululodes canindividually resist attacks by even small ants like Monomorium sp.;second- and third-instar larvae of both species seem to be lessvulnerable.

VI. DIscvssIoIt is difficult meaningfully to compare the eggs and repagula o

Ululodes mexicana and Ascaloptynx furciger with those of othertypes o owlflies, largely because our ignorance of the biolo.gy oother ascalaphids is so proound. Only the eggs o acalaph[nespecies have been described in any kind o detail. New (97)observed the eggs and repagula o two species in the neuroptynginegenera Byas and Episperches, but his descriptions are by no meanscomplete. Despite such difficulties, we will attempt some compari-sons of our ndings with those o other workers, and will emphasizewherever possible the phylogenetic implications o these comparisons,especially as they bear upon the relationship between the Ascalaphinaeand Neuroptynginae.

A. TH] EGGIn general form, color, and size the eggs o Ululodes and Asca-

loptynx resemble those described or other ascalaphids: EuropeanAscalaphus macaronius (Scopoli) (Brauer, 854) and Ascalaphus

Ienry Ululodes and Ascaloptynx 7

Figure 8. Detail ot eggs of Ascaloptynx furciger, three to four days old.

longicornis Linnaeus (Ragonot, 878); Indian Helicomitus insimu-lans (Walker) (Westwood, 888) and H. dicax (Walker) (Ghosh,93) Central and South American Col’obopterus sp. (Withycombe,925) and C. dissimilis McLachlan (New, 97); AmericanUlulodes (various species, described by Guilding, 827 McClendon,9o; New, 97); Madagascan Balanopteryx umbraticus Fraser(Fraser, 957); and Brazilian Byas sp., Episperches arenosus

(Wa.lker), Ascalorphne impavida (Walker), and Cordulecerusalopecinus (Burmeister) (New, 97). Those of Ascaloptynxfurciger seem to be larger and more colorful than most, riva.lingin size the eggs of the neuroptyngine genus Byas (New, 97I)and in color the yellowish eggs of Ascalaphus (Brauer, 854;Ragonot, 878; Naves, 95). The structure and placement of themicropyles observed in both Arizona species are basically the sameas in other species of Ascala.phidae and Myrmeleontidae (Withy-

8 Psyche IMarch-June

3mm

Figure 9. Mass defensive reaction by newly hatched, gregarious larvaeof ztscaloptynx [urcitler.

1972] Henry Ululodes and Ascaloptynx 19

combe, 1925). Ululodes and Ascaloptynx also share with otherowlflies and antlions the presence o a line o weakness girdlingthe cephalic pole o the egg; Brauer (185) and Ragonot (1878)were amiliar with this "egg cap" and with its unction duringeclosion in the genus Ascalaphus, but did not elaborate upon itsormation or orientation.

Placement o eggs in linear rows on sprigs o grass or oliage isapparently widespread in the Ascalaphidae and even Nymphidae(Gallard, 1935). Surrounding the twig with eggs, as is done byAscaloptynx furciger, has been reported only" by Tillyard (1926)or various unidentified Australian ascalaphine species. Tillyardalso reports masses o 50 to IOO or more eggs laid on one twig byone i:emale; observations o other authors tally more closely withmy own thirty to fifty eggs for most species studied, except upto 6o in dscalor#hne impavida and 75 in Ululodes macleayanus(Guilding, 1827; New, 1971). Just as ztscalo#tynx is exceptionalin its oviposition of eggs around twigs, so Ululodes is exceptionalin placement of its eggs on end; all other ascalaphids studied gluethe mid-sections of their eggs to twigs, like dscalo#tynx. Obviously,without further information about many more ascalaphid species,one cannot decide from what we know of egg form and ovipositionhabits which conditions represent specializations.. In fact, repre-sentatives of neither the Ascalaphinae no.r the Neuroptynginae (asrepresented by dscaloptynx) display any features of egg or ovi-position that uniquely characterize one subfamily to the exclusionof the other.

B. THE REPAGULARepagula have been reliably reported only in New World asca-

laphid species--in the ascalaphine genera Ululodes, Colobopterus,,4scalorphne, and Cordulecerus (all in the tribe Ululodini), andin the neuroptyngine genera Byas, Episperches, and now .dscalo-ptynx (New, 1971 ). Dissections ot: gravid emales o. several specieso ./Iscalaphus--a European-Asian ascalaphine genus presumablyclosely related to Ululodes--seemingly confirm the absencerepagula: only egg-producing ovarioles are present in the ovaries(Brauer, I854; Du(our, I86O). Unfortunately, dissections o otherOld World Ascalaphidae have not been undertaken.

Previous studies o the repagula o several species o. Ululodes(Guilding, 1827; McClendon, 19Ol; New, 1971) reveal littleinterspecitic variation in the xCorm and arrangement o the repagula


within the genus. Whether this homogeneity in repagula morphologyextends to other genera within the Ululodini cannot be said: un-fortunately, New (97) does not clariy this point with regardto the genera Ascalorphne, Colobopterus and Cordulecerus, exceptto say that repagula o these last-named groups, were observed to be"glossy castaneous" like those o Ululodes. We have shown thatit is this very "glossy castaneous" appearance o the Ululodes repa-gulum that is most signiicant in terms o ant-repulsion; it seemslikely that the shiny repagula o these other Ululodini are alsofluid-covered and similarly serve to protect the eggs and brood rompredators.

Interpretation o repagula unction in the other subfamily, theNeuroptynginae, is ambiguous. New (1971) describes for Epis-perches spp. (Neuroptynginae) a type of repagulum which is quitesimilar to, though simpler than, that of Ululodes spp. in its rod-likeform and glossy surface texture; Byas sp., on the other hand, displaysan unspecialized egg-like repagulum very similar to that of dsca-loptynx [urciger. Seemingly, the Episperches-type of repagula couldserve as an antguard in the same manner as the Ululodes-type;however, our experiments suggest no such unctio.n for the abortiveeggs of Ascaloptynx and, probably, Byas as well. Instead, the newlyhatched gregarious larvae o dscaloptynx and perhaps of Byas---utilize the repagula as ood. It is tempting to view the conditionseen in Episperches as intermediate between relatively unspecializedor "primitive" neuroptyngines like Byas and dscaloptynx and special-ized ascalaphines like Ululodes: parental provision of food for thehatchlings in the form o abortive eggs can be interpreted aspreadaptive to the construction o. an ant-fence, in the sense thatcoating an abortive egg with insect-repellent fluid effectively con-verts that egg into a true "repagulum" or barrier. Once theirprotective function has been established, true repagula may lendadditional, less obvious advantage to the species: (I) lOSS Of theneed for the heavy, ant resistant eggshell, (2) loss of the need forrobust newly hatched larvae that are capable of group defensecorrelated with reduction in the size of individual eggs, increasein clutch-size, or both, and (3) reduction in the size of energy-consuming repagula, since protection of larvae negates the need forproviding them with food.

Conclusions concerning the relationship of the New WorldAscalaphidae to those of the Old World, based upon egg andrepagula morphology, cannot be justified. Repagula have not been

1972] Henry Ululodes and dscalopterynx 21

demonstrated in Old World owlflies, and active defense of thetwig by the gregarious larvae of Old World species appears to bethe norm, even among ascalaphine genera (Westwood, 1888, onHelicomitus insimulans; Froggatt, 19oo, on dcmonotus sabulosus;Ghosh, 1913, on Helicomitus dicax; and Tillyard, 1926, on Suha-lacsa spp.). The need for detailed studies of the life histories ofcertain key groups within the various subfamilies and tribes is verygreat.

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1860. Recherches anatomiques sur l’dscalaphus meridionalis. Ann.Scienc. nat. (4) Zool. 13(4): 193-207, pl.

FRASER, F. C.1957. Two new species of Asealaphidae from Madagascar (Neurop-

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1935. Notes on the life history of the yellow lacewing, Nym2hesmyrmeleonoides. Australian Nat. 9: 118-119.

GHOSH, C. C.1913. Life-history of Helicomitus dicax Walker. Bombay Nat. Hist.

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MACLEOD, E. G.1964. Comparative morphological studies on the head capsule and cervix

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MCCLENDON, J. F.1902. The life history of Ulula hyalina Latreille. The American Na-

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1871. An attempt towards a systematic classification of the familyAscalaphidae. Jour. Linn. Soc. Zool. 11: 219-276.


NAVES, L.1913. Sinopsis de los Ascalafidos (Ins. Neur.). lrxius de l’Institut de

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Ciencias drtes de Barcelona 11(27)" 455-480.New, T.R.

1971. Ovariolar dimorphism and repagula formation in some SouthAmerican Ascalaphids (Neuroptera). Journal of Ent. (Roy. Ent.Soc. London) 46(1): 73-77, 2 figs.

RAGONOT, M. E.1878. Notes on the eggs and larvae of dscalaphus longicornis. Bull.

dnn. Soc. Ent. France (5) 8: 120.RAMBUR, P.

1842. Histoire naturelle des insectes. Ndroptkres. Paris.TILLYARD, R. J.

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