Descriptions of the Nymphal Stages of Some North American Pentatomidae (Hemiptera-Heteroptera)x

RUSSELL M. DKCOURSKY2 AND CHARLKS 0. ESSELBAUGH3 ABSTRACT A study of various instars is presented as an aid to (Say), Trichopcpla scmivittata (Say), Ncoitiglossa sulci- identification. The external morphological characters of jrons Stal, Peribalus limbolarius Stal, Pitcdia pcrsimilis nymphs are discussed, and a detailed description is given Horvath, Thyanta custator (Fabr.), Cosmopcpla bimacu- of each instar (with very few exceptions) of the follow- lata (Thomas), Ocbalus pugnax (Fabr.), Acrostcrnum ing 1(> species: lutschistus variolarius (P. de B.), E. hilarc (Say), Podisus maculivcntris (Say), and Pcrillus i-uschistaides (Voll.), li. tristigmns (Say), Mormidca bioculatus (Fabr.). At least one instar each of 14 of lut/cns (Fahr.), Cociuts dclius (Say), Mcncclcs inscrtus these species is illustrated. Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 There is an ever increasing' need for life history nymph is usually almost as broad as long, the greatest .studies and descriptions of immature stages in the width being across the abdomen, slightly caudad of various disciplines of Entomology. The taxonomist, the thorax. For a day or more following eclosion the the morphologist, and the economic entomologist have nymph appears truncate posteriorly due to the abdo- found that the study of immature stages often serves men's being slightly drawn up beneath. After about 24 to increase their understanding of current problems. hours the abdomen straightens out, leaving the nymph Exact and adequate descriptions of nymphal instars rather abruptly tapered posteriorly. At this stage the should prove useful in a variety of ways toward fur- nymph is broadly oval or somewhat elliptical in gen- thering our knowledge of this large family, the Pen- eral outline. Since the abdomen becomes more dis- tatomidae. Illustrations are usually a helpful adjunct tended than the other body regions in the feeding to the descriptions and so are included. 'instars, the nymph becomes pyriform in shape dur- At the beginning of the century only a few en- ing the latter part of these instars. It is proportion- tomologists recognized the need for identifying im- ately broader than the adult in the earlier instars but mature stages, Guide (1902), Kuhlgatz (1905). In gradually approaches the final form except that it is recent years, many authors have described or re- much less angular. The head is strongly declivent ferred to nymphal stages of the Hemiptera-Heterop- during the first instar but becomes less so except in tera including the Pentatomidae. Among these are those species in which this is characteristic in the DuPuis (1947), Ksselhaugh (1948), Guide (1934), adult stage. Miller (1956), Puchkova and Puchkov (1958), The pronotum is fairly well developed in the first Southwood and Leston (1959), Tullgren (1918), and instar except for the humeral angles, which are non- Weber (1930). existent. The mesonotum is not greatly differentiated There are, of course, numerous papers referring to since its distinctive characters, the mesonotal wing- nymphs of certain genera of the Pentatomoidea. Many pads and scutellum, develop only gradually during of these articles deal with applied aspects of economic the third, fourth, and fifth instars. In the early in- entomology. stars, before the development of mesonotal wing-pads There have been relatively few keys for the iden- and scutellum, the metanotum is exposed, but in later tification of nymphal stages, however Butler (1923) instars it is largely covered by these structures. In discussed nymphal characteristics of British Hemip- the fifth instar, the visible portions of the metanotum tera-Heteroptera, and Jordan (1951) presented a consist of the medial margins of the wing-pads and key to the nymphs of families based on representatives a median portion just posterior to the developing present in Germany. Leston and Scudder (1956) pub- scutellum. lished a key to the larvae of families of British Hemip- Unlike in the adult, the tergum is completely ex- tera-Heteroptera. Puchkov (1959) discussed the posed except for that portion covered by the wing- larvae and included a key to the families of Penta- pads during the final instar and it therefore furnishes tomoidea. Southwood (1956) formulated a key for a new set of recognition characters. The principal determining an individual instar of heteropterous features here are two series of rather heavily scler- larvae although he stated that it is not entirely re- otized plates, a mediodorsal series and a lateral series liable for pentatomoid larvae. along the lateral margins. Both series usually stand out against their backgrounds by color contrast, be- KXTKRNAL FEATURES ing almost invariably darker or at least with dark Pentatomid nymphs vary somewhat in outline but margins. Hart (1919) named these the median and usually are not much elongated. The newly hatched lateral plates, respectively, and there seems no reason to change the nomenclature. The number of units in 1 Accepted for publication August 14, 1961. - Department of Zoology and Entomology, University of the median series varies somewhat, due to the pres- Connecticut, Storrs. ence or absence of small vestigial ones. There are :l This paper was in preparation by the late Charles O. Essel- baugh just prior to his death, and the descriptions and illustrations three principal plates in the median series and these are in large part his work. The manuscript has been edited and revised by the senior author. are the ones usually referred to. These differ from 323 324 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 the others not only in size but they have a more def- frequently a week or 10 days between the molting of inite margin and contain also the paired openings of the first and last individuals and there may be a dif- the dorsal scent glands. The pleural ostioles of the ference of nearly 3 weeks between the minimum and adult are absent in the nymph. maximum for these instars of a given species. The first of these plates, located between the third In a very general way it can be said that the first and fourth abdominal segments, is not so well de- instar lasts about 3 or 4 days, the next three about veloped, in our species at least, as are the other two. a week each and the last about 12 days, making The other two median plates are larger, the transverse about 5 weeks in the nymphal stage. dimensions usually being about the same as those of Molting.—In common with all creatures which the first plate but the longitudinal one being greater. must undergo this ordeal, the freshly emerged in-

All three contain a transverse slit or suture with an dividuals are incapable of much muscular movement. Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 opening at either end. In the case of the first plate Lacking means of protection, they are then prey to this opening consists of a simple loop, but in the many forms which might not molest them at other others the distal portion of the loop appears to have times. A given individual is often subject to attack been squeezed practically together, forming a sort not only from those which have molted and hardened of loose fold and the latter then bent cephalad to first, but also from individuals of other instars. The form a rather open hook. The last two glandular only means of protection open to the individual is to plates lie between the fourth and fifth and the fifth retire to some more or less secluded spot before and sixth tergites. molting. The lateral plates consist of eight pairs of what Another cause of mortality at this time is the mere appear to be patches lapped over the edge of the inability of the individual to completely divest itself abdomen, a pair to each of the first eight segments. of the old skin before the new one hardens. Some The name usually refers specifically to the portion die outright and others are left so crippled as to inter- on the dorsum, which is usually more or less semi- fere with feeding or other body functions. Atmos- circular but is oblong in some species. The proximity pheric humidity is very important at this time. Too of the plates to each other is determined chiefly by rapid evaporation does not give the molting nymph the extent of distention of the abdomen. sufficient time to free itself and excessive humidity The genitalia have no sex differentiation but, ac- may be conducive to attack by fungi. cording to Hart (1919), in the male the penultimate A freshly molted nymph or adult is decidedly lack- sternite is swollen and often longer at the middle than ing in pigment and is very pale, except the eyes at the ends and sometimes there is a triangular de- which are usually red. Like the nymph which has pression on the hind margin of this segment, notch- just hatched from the egg, the freshly molted one ing the swollen portion. In preserved specimens this begins darkening within a few minutes, the head, does not seem to show distinctly enough to be re- thorax, and median and lateral plates showing the liable. most pronounced change. During all the nymphal instars the number of an- A day or so before molting the nymph becomes in- tennal segments is four, or one less than in the adult. active to a considerable extent and stops feeding. At At this time the second segment is disproportionately this time it isolates itself if opportunity offers. Be- long, becoming increasingly so with each succeeding fore molting actually begins, the tarsal claws are instar. The same condition as regards the number of firmly set into the substratum as this aids greatly segments holds for the tarsi, where there are two in in freeing the legs from the skin later. The old skin the nymph and three in the adult. There is an ex- splits on the middorsal line of the notum and the ception in the small subfamily Acanthosomatinae, thorax begins bulging out, gradually opening the where both nymphs and adults have two segments in split wider. The head is released from the old skin the tarsi. by the breaking of the frontal suture, the old cover- ing being thrown forward, hinged at the anterior NYMPHAL DEVELOPMENT end. The head, antennae, mouthparts, etc., are now The number of nymphal instars is typically five. withdrawn from the old skin, the covering of the Little generalizing can be done concerning the dura- eyes remaining attached to the epicranium. The legs tion of the different nymphal instars. Taking the are freed next and the abdomen last, the nymph group as a whole, each succeeding instar is of some- standing upright upon its cauda just before finally what longer duration than the preceding one. The getting free. second, third, and fourth, however are usually of Determination of Instars.—Knowing which instar nearly equal length. The first instar is, however, is at hand is sometimes a matter of some importance. consistently the shortest and the fifth the longest. The following characters have served very well for Uniformity of duration, too, seems to decrease with the species examined, but may not hold good for all each succeeding instar. Seldom in the first instar is species. Size is, of course, a consideration but is not there more than 24 hours elapsed time between the entirely reliable, even if the species is known. molting of the first and last individual hatched from The first instar is characterized by a complete lack a given egg mass and usually there is considerably of punctation or dots resembling punctures. The less. In the fourth and fifth instars, however, there is head, notum, legs, mediodorsal plates, and lateral 1962] DECOURSEY AND ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 325 plates, and also the antennae (except for pale in- forming pale design somewhat suggesting an anchor. cisures), are concolorous. In the species examined Caudad of the three principal plates are two smaller these parts have always been very dark, either dark ones of similar color but indefinite in shape and not chocolate-brown or black and always shining. sharply defined. Ventral surface similar in color to In the second instar the head and notum may be- corresponding part of dorsum. Rostrum mostly pale come whitish and the beginnings of punctation make but fuscous toward tip, stout, but slightly exceeding their appearance. These may be either shallow punc- posterior trochanters. Legs concolorous with thorax tures or dark dots resembling punctures but not and head, clothed with a few pale setae, tibiae not actually impressed. Most of the lateral plates will sulcated. Ventral portion of lateral plates smaller contain just a few of these dots, the number ranging than dorsal portion, emarginate, becoming less so from none to three. posteriorly. Spiracles located in emargination of Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 The third instar is in most respects very similar to lateral plates and bounded by somewhat dark oval the second except for size, but one clue to its recog- area. One spiracular puncture visible on each seg- nition lies in the number of dots on the lateral plates, ment save first, located about 45° caudad and mesad in this case about four to seven each. There is evi- of its spiracle. Venter with median series of five ob- dence also of the developing scutellum. long, more or less infuscated plates, one on each of The fourth instar will have still more of the dark the last five segments. dots, by now perhaps slightly sunken, on the lateral Second Nymphal Instar.—Length, 2.0-2.6 mm.; plates, but now there is evidence of development of width, 1.5-2.1 mm. Form oval, widest point as before. wing-pads on the posterior margin of the mesonotum. Head more nearly porrect. Head and thoracic nota The wing-pads will have just attained the posterior whitish with dark, coarse, shallow punctures, or margin of the metanotum. The fifth instar resembles merely dots and certain rather definite paired dark the fourth except that the wing-pads now exceed the areas, nota having impunctate median line. Juga metanotum. a bit more rounded than in previous instar. An- tennae roseous to fuscous except for pale annul i at Eusch'tstus variolarius (Palisot de Beauvois) joints; ratio of antennal segments approximately First Nymphal Instar.—Freshly molted nymphs 6:9:8:15. Dark elliptical spot just mesad of each mostly pale yellow but thoracic nota nearly translu- eye. Paired dark markings on pronotum have some- cent and eyes scarlet. Within a few minutes the head, what the form of a "J," remote from anterior margin, thorax, appendages, and lateral and mediodorsal those on meso- and metanotum somewhat quadrangu- plates become slate-gray and eventually fuscous. lar and adjacent to anterior margins. Lateral mar- Nymphs about 1 day old are 1.3 mm. long and 1.2 gins of thorax serrulate and explanate, no indication mm. wide. of developing wing-pads on posterior margin of Before the first molt, a length of 1.7 to 1.8 mm. mesonotum. Dorsum of abdomen white with crimson is attained but the width only increases to 1.3 mm., to red bars extending from sutures to pseudosutures, giving the nymph a more elongated form than be- bars replaced by irregular splotches about and between fore. Form broadly oval, widest at third pair of median plates. Median plates as in previous instar lateral plates. Head and thorax slate-gray to fuscous, except now nearly black, third plate with anterior thoracic nota with pale median line. Head strongly margin barely rounded and first dark only around declivent. Antennae reddish to fuscous with pale margin. Small median plate between sixth and annuli at joints. Ratio of antennal segments approxi- seventh tergites acuminately pointed and constricted mately 7:9:7:20; apical segment somewhat fusiform. at middle. Eighth tergite with somewhat transverse Tylus clavate, considerably exceeding juga, which dark spot which may be constricted or completely are rather acute. Lateral margins of thorax slightly divided at median line. Lateral plates concolorous to moderately explanate. Posterior margin of meta- with head and nota, the dark, shallow punctures notum straight except near lateral margin, where usually 0-2 in number but rarely 3 or 4 and small. it curves cephalad. Dorsum of abdomen with pattern (This character definitely determines the instar.) of irregular crimson cross-bars running between pale Ventral surface similar to dorsal, the head and sutures and intervening pseudosutures which are thorax being mottled or punctured with dark color likewise pale. Cross-bar pattern extends two-thirds (nearly black). Under side of head dark with trans- to three-fourths the distance from lateral plates to verse pale area which is interrupted beneath anten- mediodorsal line. Lateral and mediodorsal plates im- nal sockets, which are pale. Coxae, trochanters, and punctate, concolorous with head and thoracic nota. proximal half of femora hyaline to whitish, remainder Dorsal portion of lateral plates suggests Gothic arch of leg dark, setae concolorous with part bearing them. but becomes more drawn out as nymph becomes more Tibiae sulcated. Rostrum pale to middle of second distended preparatory to molting. Three principal segment, then gradually becoming fuscous or blackish median plates equal in length but dissimilar in shape, distally. Venter as in previous instar except median the first nearly linear and slightly constricted at plates now darker and more distinct, last four ex- median line, the second nearly rectangular but with tending beneath posterior margin of preceding seg- posterior corners rounded off, the third plate oval. ment. Lateral plates truncate instead of emarginate. All plates pale along glandular slit and median line, Two spiracular punctures now accompany each 326 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 spiracle except the anterior one, the new puncture somewhat darker than others, all segments with a being smaller than the first and directly caudad of few pale hairs. Lateral margins of thorax moderately the spiracle. explanate. Tergum of abdomen whitish with small Third Nymphal Instar.—Length, 3.4-4.5 mm.; irregular flecks of red, more dilute on disk. Sutures width, 2.4-3.0 mm. Form oval with tendency to be- and intervening pseudosutures pale. Lateral and come pyriform as abdomen distends preparatory to median plates concolorous with thoracic nota; form molting. Round dark spots on head and thoracic of lateral plates subtriangular. First median plate nota now slightly depressed. Juga and tylus now linear, second rectangular with posterior angles forming an almost continuous curve. Antennae fus- rounded, third subelliptical. Glandular sutures and cous except after molting, annuli pale. Ratio of length middorsal line paler. Margins of entire insect with of antennal segments 5:8:7:10, with second quite a few short hairs. Venter similar to dorsum but paler. Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 variable. Thoracic margins less explanate in dis- Lateral plates on ventral surface with mesal margin tended individuals. Barred effect on tergum of abdo- broadly rounded, posterior side somewhat less so men becoming less pronounced, reddish markings on than anterior. Spiracles and spiracular punctures some individuals giving way to olive-green on pale fuscous, outer puncture visible only under high mag- yellowish-green background, except about median nification. Legs gradually become fuscous. Rostrum plates, where markings are crimson blotches. Lateral attains posterior margin of fourth abdominal sternite, plates with about 5 to 8 small shallow punctures and pale at first, except at tip, but infuscation proceeds thinner black margin at sides than before; apex of toward base. plates an irregularly rounded black spot. Median Second Nymphal Instar.—Length, 2.0-2.9 mm.; plates with a few fuscous punctures on pale portions, width, 1.4-2.0 mm. Tylus considerably exceeding both before and behind glandular suture. Ventral juga, but more gradually dilated apically than in the surface not much changed. Transverse white area preceding instar. Ratio of length of antennal seg- on head little or not at all interrupted below antennal ments approximately 7:10:8:15, apical segment less sockets, but with fuscous punctures. Punctures on dilated than in previous instar. Anterior margin of pleura becoming more numerous and more deeply im- third median plate straight or with slight angle at pressed. Median spots on venter becoming more middorsal line. Transverse pale area on ventral side dilute and with a few small fuscous dots. Lateral of head usually less extensive than in variolarius plates less distinct and also less angular. Other but antennal sockets pale as in that species. Other characteristics as in preceding instar. characters as in variolarius. Fourth Nymphal Instar.—Length, 5.0-5.7 mm.; Third Nymphal Instar..—Length, 3.0-4.6 mm.; width, 3.4-4.0 mm. Ratio of length of antennal seg- width, 2.3-3.1 mm. Tylus now less prominent and ments approximately 7:14:10:15. Wing-pads have less dilated, same length as juga. Ratio of length started development, attaining posterior margin of of antennal segments 9:18:15:22; apical segment now metanotum, the latter yet unchanged. Lateral plates little stouter than others. Barred effect on dorsum with about 15 fuscous spots each. Ventral surface of abdomen less pronounced on many individuals, may of head now mostly pale, only apex of juga, narrow become pale greenish. Other characters similar to anterior margin of bucculae, and posterior margin preceding instar except spols on lateral plates, which of genae remaining fuscous. Legs pale except tarsi, number about five to eight. which are fuscous, setae on femora and tibiae arising Fourth Nymphal Instar.—Length, 4.8-5.6 mm.; from fuscous spots. Other characters as in preceding width, 3.3-4.2 mm. Ratio of length of antennal seg- instar. ments approximately 7:16:11:15. Tylus and juga Fifth Nymphal Instar (fig. 1).—Length, 7.0-9.8 about same length. Humeri not prominent. Wing- mm.; width, 4.2-6.3 mm. Ratio of length of antennal pads reach posterior margin of metanotum. Margins segments approximately 8:22:15:19. Meso- and of lateral plates less conspicuous, frequently only a metanotum about equally developed, both sets of wing- round dark spot at apex visible. Ventral surface of pads extending to point opposite anterior margin of head mostly pale, except apex, which remains black. second median plate. Abdominal tergites frequently Disk of venter entirely pale. Other characters as for with minute reddish or fuscous punctures. Other preceding instar. characters as in preceding instars. Fifth Nymphal Instar.—Length, 7.0-8.3 mm.; width, 4.5-5.9 mm. Ratio of length of antennal seg- Euschistus euschistoides (Vollenhoven) ments approximately 8:22:16:19. Juga exceed tylus. First Nymphal Instar.—Length, 1.10-1.75 mm.; Wing-pads extend beyond posterior margin of meta- width, 1.10-1.35 mm. Form nearly circular to broadly notum as in other species. Other characters as in oval, sometimes broader than long. Head and thorax preceding instar. olivaceous-brown with indefinite paler region on pos- terior portion of head and disk of thoracic nota, nar- Euschistus tristigmus (Say) rowing posteriorly. Tylus greatly exceeds juga, sud- First Nymphal Instar.—Length, 1.1-1.6 mm.; denly dilated before latter. Antennal segments in width, 0.99-1.2 mm. Form almost elliptical. Colora- ratio of approximately 3:4:4:10, roseate to casta- tion as in variolarius and euschistoides in all particu- neous, apical segment somewhat fusiform and usually lars. Ratio of length of antennal segments approxi- DKCOURSEY AND EssEi.BArcni: NYMPHAL STAGES OF SOME PENTATOMIDAE 327 mately 4:4:4:10; apical segment somewhat fusiform; bars across tergites. Head less deflexed than in pre- all segments with a few scattered pale hairs. Lateral ceding instar, margins very shallowly sinuate, tylus margins of thorax moderately explanate. Tergum exceeding juga. Antennae stramineous except apical of abdomen as in the above species except for the two-thirds of fourth segment, which is fuscous. third mediodorsal plate, which in this species has a Lateral margins of thorax somewhat expanded, nota tendency to have a very obtuse angle on the anterior otherwise as in preceding instar. Lateral plates about side and is cleft at the median line on the posterior same color as expanded margins of thorax, twice side. Marginal hairs and markings on venter as in as wide as deep, punctures almost invisible. Median above species. Anterior three pairs of lateral plates plates concolorous with disk of thoracic nota, im- on ventral surface usually with emargination ad- punctate. First median plate attenuated at ends, con- jacent to spiracle. Legs and rostrum as in above stricted at median line, third median plate semi- Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 species. circular. Head somewhat paler below than above, Second Arymphal Instar.—Length, 1.7-2.7 mm.; impunctate below. Pleura concolorous with thoracic width, 1.4-1.7 mm. Ratio of length of antennal seg- nota, a few punctures present. Rostrum less stout ments approximately 7:9:8:14; apical segment less than in preceding instar, pale castaneous except for dilated than in preceding instar. Color and structural fuscous tip, slightly surpasses last pair of coxae. Legs details as in variolarins. paler than pleura, concolorous, tibiae not sulcated. Third Nymphal Instar.—Length, 2.7-3.8 mm.; Venter same general color as tergum but flecked in- width, 2.0-2.5 mm. Form more broadly oval than stead of barred with scarlet. Medioventral plates, that of the two foregoing species. Tylus remains spiracles and spiracular punctures infuscated. Lateral very prominent. Ratio of length of antennal seg- plates almost hyaline, not clearly defined. ments approximately 4:7:6:9. Medioventral plates Third Nymphal Instar.—No specimens available. with longer transverse dimension than in either of Fourth Nymphal Instar.—Length, 2.5-3.0 mm.; the above species. Other characters as in preceding width, 2.0-2.3 mm. Form broadly oval to elliptical. instar. Head moderately deflexed, margins rather deeply Fourth Nymphal Instar.—Length, 4.0-5.2 mm.; sinuated before eyes. Tylus still somewhat exceed- width, 3.0-3.5 mm. Ratio of length of antennal seg- ing JuSa ancl broad apically. Antennae usually pale ments approximately 4:12:9:13. Humeri prominent except apical three-fourths of fourth segment, which and somewhat upturned. Barred markings on ter- is fuscous; ratio of lengths of segments approxi- gum of abdomen still very pronounced, lateral plates mately 6:10:11:16. Thoracic nota shining fuscous with black crescent at apex. Other characters as in with whitish lateral and anterior margins, median preceding instar. stripe, and vittae; median stripe impunctate but re- Fifth Nymphal Instar.—Length, 6.4-7.3 mm.; mainder with fuscous punctures, vittae extending width, 4.2-4.9 mm. Ratio of length of antennal seg- caudad from anterior margin of mesonotum, along ments approximately 7:21:15:17. Humeri as in pre- ends of median plates and uniting medially posterior ceding instar but even more prominent. Tylus longer to latter, portions on abdomen impunctate but with than juga. Medioventral spots very much as in adult. a few flecks of red. Abdominal tergites, except on vittae, transversely barred with white and sangui- Mortnidea lugens (Fabricius) neous, the latter predominating. Lateral plates about First Nymphal Instar (described from single speci- twice as wide as deep, outer half of each white, form- men).—Length, 0.88 mm.; width, 0.69 mm. Form ing continuous white margin about abdomen, apical oblong. Head strongly deflexed, juga oblique, much portion of plates piceous, impunctate. Median plates exceeded by tylus. Antennae pale castaneous, apical piceous, rugose, but impunctate. Pleura and ventral segment with pale pubescence; ratio of lengths of an- side of head castaneous to fuscous, head sparsely tennal segments approximately 5:4:5:13. Head, punctate, pleura more densely so. Rostrum pale ex- thoracic nota, and plates dilute fuscous, abdominal cept for fuscous stylets and somewhat infuscated api- tergum red. Posterior margin of mesonotum sinuated, cal segment. Legs stramineous except apex of last having a rather decided bulge medially and lesser tarsal segment, which is somewhat infuscated, tibiae bulges near lateral margins. Lateral plates triangular without sulcus. Venter similar to tergum except to semicircular, median plates equal in length. Ven- lateral plates, which have no dark apex. Medioventral tral surface similar in coloration to dorsum. Legs plates fuscous, well defined. pale castaneous. Rostrum stout, attains fourth ab- Fifth Nymphal Instar (fig. 2).—Length, 3.6-4.5 dominal sternite, concolorous with legs except tip, mm.; width, 2.6-3.2 mm. Form oval to broadly oval. which is somewhat infuscated. Ventral portion of Head moderately deflexed, piceous to castaneous, lateral plates only slightly smaller than dorsal portion punctured with fuscous, lateral margins as in pre- but with inner margin oblique, posterior side being ceding instar. Juga rather acute apically, equal to the longer. tylus, which is broad apically. Antennae generally Second Nymphal Instar.—Length, 1.1-1.6 mm.; pale except apical portions of segments 3 and 4, width, 0.8-1.0 mm. Form elongate oval to broadly which are usually fuscous; ratio of lengths of seg- oval. General color, head and thorax castaneous, ments approximately 8:18:16:22. Thoracic nota as punctate, dorsum of abdomen whitish with scarlet in preceding instar except for greater development of .328 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 wing-pads, color varies from castaneous to fuscous width, 1.7-2.2 mm. Ratio of length of antennal seg- but vittae are white as in preceding instar and are ments approximately 7:12:9:16. Form and color quite constant. Dorsum of abdomen and entire ven- pattern mostly as in preceding instar. Dorsal aspect tral surface marked as in preceding instar, tibiae of lateral plates shows 0-3 dark spots per plate. not appreciably sulcated. Second and third median plates with dark portion rather widely separated by white median mark, first Coenus delius (Say) plate all pale except thin margins of fuscous, very First Nymphal Instar.—Length, 1.24-1.66 mm.; few fuscous punctures present, these all anterior to width, 0.95-1.13 mm. Form elongate oval. Head slits and mostly on first plate. Slit almost at posterior moderately declivent, margins oblique, not sinuated margin of plates. No change in ventral aspect except before eyes. Tylus exceeds juga, dilated apically. median spots on venter are very indistinct. Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 Antennae stout, dark with reddish annuli. Ratio Fourth Nymphal Instar.—Length, 3.5-4.1 mm.; of length of antennal segments approximately 3 :3:3:6. width, 2.8-3.1 mm. Ratio of length of antennal seg- Head and thoracic nota yellowish-brown, becoming ments approximately 9:18:12:20. Little change in darker during latter part of instar. Thoracic margins form or color pattern. Tylus still longer than juga not greatly expanded. Abdominal tergum whitish, but less so than in earlier instars. Lateral plates bear flecked with scarlet. Lateral plates concolorous with five or six shallow punctures each. A few dark nota, impunctate, apical angle acute. Median plates punctures now present caudad of slit in third medio- of equal length, color somewhat more dilute than dorsal plate. that of lateral plates, limits not clearly defined. Fifth Nymphal Instar (fig. 3).—Length, 5.0-8.0 Glandular slits and openings paler than remainder mm.; width, 4.0-4.6 mm. Tylus and juga about equal of plate. Ventral side of head usually somewhat in length. Ratio of length of antennal segments paler than dorsum. Pleura concolorous with nota. approximately 15:28:19:29. Not much change in Sternum and venter concolorous with tergum. Me- form but entire dorsum paler in color, some specimens dian plates not clearly defined, but rather more shin- being nearly white. Thoracic nota largely impunc- ing than remainder of venter. Lateral plates with tate on disk. Fuscous portion of last two medio- inner margin oblique. Spiracles fuscous, conspicuous. dorsal plates reduced to two oval or triangular and Spiracular punctures present, outer one less con- two crescentic spots each, punctures present both spicuous. Legs and rostrum concolorous with pleura, anterior and posterior to slit. Tibiae and femora except tarsi and apex of rostrum, which are fuscous. now pale to tawny, spines fuscous, often arising from Tibiae not noticeably sulcated. fuscous spots. Second Nymphal Instar.—Length, 1.7-2.4 mm.; width, 1.2-1.6 mm. Form oval to broadly oval, Menecles insertus (Say) broadest at second pair of lateral plates. Head fairly First Nymphal Instar (fig. 4).—Length, 1.42-1.67 porrect, margins sinuated before eyes. Tylus exceeds mm.; width, 1.24-1.42 mm. Form broadly oval, juga by nearly its own width, dilated apically. Eyes broadest at third pair of lateral plates. Head, thorax, dark mahogany. Antennae black, as thick as femur, median and lateral plates chocolate-brown. Head first articulation white, shallow, other articulations moderately declivent. Tylus exceeds juga. Antennae deeply cut, reddish. Ground color of head and stout, mahogany to castaneous with pale annuli, thoracic nota whitish with shallow black punctures. apical segment somewhat dilated. Ratio of length of Median line and margins impunctate, margins ex- antennal segments approximately 5:5:5:13. Lateral panded. Abdominal tergum white, with short bars margins of thorax slightly compressed, but not ex- and irregular splotches of scarlet. Lateral plates planate. Mediodorsal line and frontal sutures orange- pearly white, but with apex black, acutely angled. red. Dorsum of abdomen orange-red except for Median plates also white, interrupting front margin plates, which are concolorous with thoracic nota. of plates. Ventral side of head blackish, with broad, Sometimes one or two linear darkened areas before transverse, pale bar reaching entirely across at an- first median glandular plate. Glandular slits not tennal sockets. Proximal half of rostrum pale, re- pale-bordered, inconspicuous, pale mediodorsal line mainder fuscous. Pleura mottled black and white. lacking. Second median plate rectangular, third oval. Legs pale from coxae to apical third of femur, re- Lateral plates pentagonal except first pair, which are mainder fuscous to piceous except outer lateral angles smaller and triangular. Ventral surface of head, of tibiae, which are calloused white to apical fourth. pleura, and legs (except tarsi) concolorous with head Tibiae conspicuously sulcated, due to bottom of sul- and thoracic nota, tarsi testaceous. Rostrum with cus being wine-colored and so contrasting sharply proximal segment testaceous, becoming increasingly with shiny white margins. Venter concolorous with infuscated toward tip, which is quite fuscous. Ster- tergum but with little or no barred effect, all or num and venter orange red, the latter with indefi- nearly all red markings being irregular splotches. nite, slightly infuscated areas on disk. Lateral plates Median ventral plates more or less fuscous. Lateral on venter similar to those on dorsum but apex more plates similar to dorsal portion. Spiracles and obtuse. A very few marginal hairs on all body spiracular punctures piceous. regions. Tliird Nymphal Instar.—Length, 2.6-3.5 mm.; Second Nymphal Instar (fig. 5).—Length, 2.20- DECOURSKY AND ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 329

2.55 mm.; width, 1.60-2.20 mm. Form elliptical at half of tylus being distinctly dark. First two an- first, becoming oval with age. Tylus rounded, exceed- tennal segments reddish, third and fourth almost ing juga. Antennae dark mahogany except for pale piceous. Thoracic margins somewhat explanate and annuli, less stout than in preceding instar. Ratio anterior angles approximately rectangular. Pairs of of length of antennal segments approximately 8:10:- impunctate areas on thoracic nota, those on pronotum 9:18. Head somewhat declivent. Head and thoracic approximately V-shaped, with the angle directed nota whitish, with rather remote, very shallow, fus- mediad and containing 8 or 10 punctures within the cous punctures; head with irregular fuscous area "V"; those on mesonotum shaped like quotation niesad of each eye, and notum with very thin, im- marks, the posterior one somewhat smaller. Meta- punctate median line. Thoracic margins serrulate and notum concealed by mesonotum and wing-pads at explanate, extending cephalad to middle of eye. An- sides and middle. Each abdominal tergite with Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 terior margin of metanotum with oblong fuscous pseudosutures extending two-thirds the distance to area each side of disk, irregular impunctate areas the middorsal line. Median plates shallowly and directly cephalad to it on mesonotum and pronotum. sparsely punctured and slightly rugose. First lateral Abdomen creamy white with crimson sutures and plate nearly concealed by wing-pad. Lateral plates pseudosutures, each connected by bars or cross- semicircular, bounded by thin fuscous border and ties of crimson and each cross-tie containing one containing about 25 punctures each, last pair of minute fuscous puncture, the latter forming two trans- plates deeper than wide, smaller. Anal and anteanal verse rows for each abdominal tergite. Area between plates subquadrate. Venter with median row of five median plates crimson. Median plates pale but with subquadrate, fuscous spots and the sixth, containing fuscous punctures before and behind glandular slit the anus, fuscous-margined. Spiracles fuscous, the and with considerable diffusion of fuscous, especially spiracular punctures red, somewhat elevated and before slit, on last two glandular plates. Glandular separated from the spiracle by the pseudosuture. slit on first plate located near posterior margin; all The three form an isosceles triangle as in the second median plates pale on middorsal line. Last two instar. glandular plates nearly similar in shape but last one Fifth Nymphal Instar (fig. 6).—Length, 8.5-11.0 with posterior margin rather more convex. Median mm.; width, 5.8-7.0 mm. Form almost elliptical. fuscous area on eighth abdominal tergite composed of Resemblance to adult now very striking. Head punctures, similar to thoracic nota, but with diffused rounded off in front, tylus about same length as juga, infuscation between. Lateral plates concolorous with both thickly but finely punctate with very dark punc- thoracic nota, semicircular to subtriangular in form, tures. Eyes dark red, antennae reddish except fourth with fuscous margin and two to five poorly defined segment and part of third, which are dark. Thoracic fuscous dots. Ninth abdominal tergite continuous margin strongly explanate, anterior angles promi- and concolorous witli lateral plates. Ventral surface nent; nota ochreous, thickly set with shallow fuscous of head fuscous, except bucculae and antennal sockets, punctures. Wing-pads considerably developed, reach- which are pale; proximal half of rostrum pale, re- ing the posterior margin of second abdominal tergite. mainder fuscous. Pleura fuscous, with longitudinal Abdominal tergum similar to thoracic nota except pale bars. Legs pale to middle of femora, suddenly that punctures are dark purplish as well as finer and becomining fuscous. Venter similar in color to dor- more dense. Median plates dull black, finely punctate sum of abdomen but with five fuscous median plates except for curved ends of glandular slits, which are and entire ninth sternite also fuscous; first two calloused yellowish. Lateral plates punctured with plates smaller and somewhat indefinite in outline. black. Entire lateral margin of thorax and abdomen Spiracles and spiracular punctures fuscous, forming with narrow, calloused, dull yellow border. Venter isosceles triangles, punctures twice as remote from similar to dorsum in coloration but with median row spiracle as from each other. of five black spots. Sternum black. Tibiae, tarsi, and Third Arymphal Instar.—Length, 4.6-5.0 mm.; apical portion of femora blackish, remainder fumose, width, 3.0-3.5 mm. Tylus nearly same length as tibiae sulcated. juga. Ratio of length of antennal segments approxi- mately 10:15:10:20. Head fairly porrect. Tergum Trichopepla semivittata (Say) with barred effect broken up to form mottling, punc- First Nymphal Instar.—Length, 1.10-1.20 mm.; tures more numerous than in preceding instars and width, 0.67-0.83 mm. Form elongate oval, broadest no longer arranged in rows. Area between median at about second pair of lateral plates. Head, thorax plates mottled in same manner as remainder of ab- and plates shining fuscous, impunctate, front of head dominal tergum. Median plates with middorsal line almost vertical. Tylus exceeds juga; margins of head not noticeably paler than adjoining area. Lateral not sinuated before eyes. Ratio of length of antennal plates as before but with approximately 10 shallow segments approximately 5:8:7:15, apical segment fuscous punctures. Other characters as in preceding thicker, abruptly pointed at apex. Head and thoracic instar. nota with sparse growth of pale pubescence, margins Fourth Nymphal Instar.—Length, 5.5-7.0 mm.; of each sclerite arcuated. Color of tergum somewhat width, 4.0-4.8 mm. Similar in form to preceding buff, marked with red sutures and a very few reddish instars. Head with more diffusion of fuscous, apical flecks, but mostly obscured by median and lateral 330 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 plates, the latter being particularly large, oblong in Tylus considerably elevated, longer than juga, which shape, and nearly approximate. Pseudosutures al- are acute apically. Ratio of length of antennal seg- most invisible, fully two-thirds of their length con- ments approximately 10:18:16:28. General colora- sisting only of an impression in the lateral plate. Two tion unchanged. Mesonotum shows very slight de- narrow, fuscous, sclerotized areas present before first velopment of caudal margin at lateral extremities. glandular plate, these frequently interrupted at me- Largest of lateral plates now contain about 20 punc- dian line. First median glandular plate little con- tures each. Otherwise similar to preceding instar. stricted at middle, all three plates truncate or bifur- Fourth Nymphal Instar.—Length, 3.3-4.5 mm.; cate at ends and with small notch in posterior mar- width, 2.3-3.7 mm. Form oval to broadly oval. gin at median line, no pale areas about orifices. General color bronzy fuscous except tergum of ab-

Glandular plates followed by two more heavily sclero- domen, which is nearly white with crimson sutures Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 tized fuscous areas, these and glandular plates and pseudosutures. Head rather narrow, sinuated gradually diminishing in length posteriorly; last ter- before eyes, tylus exceeds juga. Ratio of length of gite also fuscous. Ventral portion of lateral plates, antennal segments approximately 8:15:13 :20, last two except posterior ones, scarcely half as long as dorsal interstices much more deeply notched and with red- portion; ends oblique. Series of small infuscated dish annuli. Lateral pronotal margins nearly straight, median plates present on venter. Legs and rostrum entire. Wing-pads attain posterior margin of meta- pale at first but becoming increasingly infuscated notum. Head and notum finely punctate and rather during- the instar. thickly clothed with pale pubescence. Pale vittae, in Second Nymphal Instar.—Length, 1.25-1.98 mm.; whole or in part, may begin to make appearance on width, 0.93-1.24 mm. Form oval. Color as in pre- head and nota. Vittae may include a median one on ceding instar but now densely punctate and distinctly head and pronotum, with submarginal ones on pro- pubescent. Head less declivent than in preceding notum. Median and lateral plates obscure most of instar, tylus somewhat elevated apically, otherwise tergum of abdomen, which is punctate with fuscous. unchanged. Antennae fuscous with pale reddish an- Lateral plates reach halfway from margin to median nuli at joints, pubescent; ratio of length of segments plates, thickly punctate. Median plates punctate be- approximately 8:15:12:21, apical segment fusiform. fore and behind glandular slit, last two finely rugose Lateral margins of thorax nearly straight, very little before slit. Plates and tergum of abdomen pubescent. expanded. Abdominal tergum nearly white, with Ventral surface as in preceding instar. Legs bronzy scarlet sutures and a few large piceous punctures, fuscous, tibiae very shallowly sulcated. but mostly covered by the large lateral plates whose Fifth Nymphal Instar (fig. 7).—Length, 5.3-6.0 dorsal portion is about three times as long as the mm.; width, 4.2-4.5 mm. Form broadly oval. Head ventral. Pseudosutures not much in evidence. Larger strongly declivent, front almost vertical, margins lateral plates about three times as long as broad, rather feebly sinuated before eyes. Juga and tylus truncated, containing about 12 punctures each. approximately equal in length. Antennae fuscous to Mediodorsal plates preceded by one very narrow, in- piceous, with pale annuli at joints. Ratio of length terrupted piceous area, chitinized in some degree as of antennal segments approximately 10:25:20:26. plates. Mediodorsal plates of more or less conven- Notal margins arcuated, more so anteriorly on both tional form and size. Spaces separating mediodorsal pronotum and mesonotum. Head and thoracic nota plates of uniform width, the anterior two red except bronzy fuscous, deeply punctate and quite pubescent; short pale sector in middle, the anterior of these three pale vittae on head and pronotum, latter also arcuated cephalad at median line. Mediodorsal plates with pale lateral margins. Median vitta extends to punctate both anterior and posterior to glandular apex of scutellum but others may be interrupted on slit, the latter located near middle in first and third mesonotum. Vittae with fuscous punctures, pale notal plates but somewhat cephalad of middle in second margins punctured only along inner side. Tergum of plate. Glandular mediodorsal plates followed by fus- abdomen more or less flesh-colored, with large but cous, heavily chitinized areas as in preceding instar, shallow fuscous punctures and pale, sparse, but long the caudal margin of the first of these being deeply pubescence. Sutures scarlet, conspicuous. Pseudo- and sharply notched at median line. Ventral surface sutures of like color but short and thin. Lateral plates concolorous with dorsum, impunctate, glabrous. Legs unusually elongated, those immediately posterior to and rostrum fuscous to piceous, third segment of wing-pads twice as long as wide and with pubescence rostrum slightly exceeding posterior coxae. Tibiae similar to that on remainder of tergum. Median slightly sulcated. Venter reddish on disk, red be- plates also large and prominent, the three functional tween lateral plates and with indefinite yellowish ones preceded by a linear one of same length, of uni- vittae containing the fuscous spiracles and spiracular form width, and bearing a single row of punctures. punctures. Series of fuscous medioventral plates First functional median plate broader than is common present. Ends of lateral plates oblique, the caudal in the family. Glandular plates and their slits of extremities being nearer the median line, impunctate. uniform length. Median plate on seventh tergite shorter than those before it, approximately trapezoidal Third Nymphal Instar.—Length, 2.25-3.10 mm.; in form. Median plate on eighth tergite not con- width, 1.70-1.90 mm. Form oval. Few changes from tiguous with lateral plates. Ventral surface cor- preceding instar. Head feebly sinuated before eyes. DECOI'RSKY AND ESSELBAUC.II: NYMPHAL STAGES OF SOME PENTATOMIDAE 331 responds generally with dorsal in coloration but disk but transverse toward margins. Abdominal ter- sternum and under side of head, except near margin, gum also punctate and with vittae continuous with stramineous. First two segments of rostrum and legs those on thoracic nota. Lateral vittae include lateral also stramineous, remainder becoming increasingly plates. Punctures on lateral plates obsolete. Vittae infuscated apically. Venter with median series of five on disk of abdominal tergum include ends of median well-defined fuscous areas increasing in size pos- plates and terminate Avith posterior plate. Sutures teriorly, sparsely punctate on disk but moderately so red within limits of vittae but pale between vittae. elsewhere. Lateral plates on ventral side subquadrate. Median plates as in preceding instar except first Tibiae only slightly sulcated. and second can now be recognized as distinct al- though still contiguous. Posterior extremity of ab-

Neottiglossa sulcifrons Stal domen somewhat truncated. Ventral side of head Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 First Xymphal Itistar.—Length, 0.95-1.02 mm.; concolorous Avith dorsum except posterior margin Avidth, 0.74 mm. Form more or less elliptical, about which, like the pleura, is fumose. Sternum, rostrum, same width from prothorax to third pair of lateral and legs stramineous except apex of rostrum, which plates. Lateral margins of head very feebly sinuated is fuscous. Lateral Anttae on venter red except lateral before eyes. Tylus broad, somewhat exceeding juga, plates, spiracles, and spiracular punctures, which arc which are rather acute. Head strongly declivent. dark grayish. No inner vittae present on venter. Disk Antennae nearly hyaline but with slightly smoky of venter stramineous except series of median spots, tint. Ratio of lengths of antennal segments approxi- which are translucent. Ventral portion of lateral mately 2:2:2:5. Head, thorax, and plates fumose, plates unusually Avell developed, being of approxi- with sparse growth of pale hairs. First abdominal mately same dimensions as the dorsal portion. Tibiae tergite reddish from margin to margin. Two very sulcated. narrow mediodorsal plates before glandular plates, Third Nymphal Instar.—No specimens available. the first two of which are apparently fused together. Fourth Nymphal Instar (described from two speci- Last glandular mediodorsal plate very narrowly mens).—Length, 2.47-2.68 mm.; width, 1.59-1.62 mm. separated from the one anterior to it, only half as Form decidedly oblong, no longer narrowed pos- large and rather narrowly rounded off posteriorly. teriorly. Head with prominent tooth and deep sinua- First lateral plate narrow, acuminately pointed, and tion before eyes, front convex. Juga acute, consider- only two-thirds the length of the second. Second and ably longer than tylus. Ratio of lengths of antennal following pairs of lateral plates rectangular, anterior segments approximately 4:6:5:12. Overall color has ones twice as long as Avide, becoming progressively changed someAvhat, being less yellow and more tinged .shorter posteriorly. Lateral plates narrowly separated with fuscous. Punctures darker and more conspicuous by the scarlet suture. Pseudosutures so minute as to than in second instar. Vittae now fuscous, somewhat be almost invisible. Tergum of abdomen, aside from less distinct or entirely absent on head, lateral ones plates, dull yellow, somewhat suffused with reddish. not extending anterior to front margin of eye. Pleura and A'entral side of head about same color as Thoracic nota much as before but wing-pads begin- dorsum but paler medially. Legs and rostrum pale ning to form, extending nearly to base of metathorax. basally but last three segments of rostrum and tibiae, Lateral vittae include apical 60% of lateral plates, and half of femora somewhat fumose. Tibiae Avith remainder of plates pale with fuscous punctures. soft pale hairs, feebly sulcated. Venter somewhat Diffusion of reddish color about vittae as in second more pale than tergum of abdomen, median spots not instar. Ventral surface of head, pleura and venter Avell defined. Lateral plates on venter drawn out to IIOAV punctate. Other characters in agreement with a blunt angle, just mesad of Avhich is the fumose those of second instar. spiracular puncture. Spiracles borne on elongate Fifth Nymphal Instar (fig. 8, description from fumose spots Avhose long axis is transverse. These single specimen).—Length, 3.8 mm.; width, 2.5 mm. elongate spots are placed between points of lateral Ratio of lengths of antennal segments approximately plates, anterior sides of which are notched somewhat 6:10:10:15. Form and markings as in preceding in- to make room for them. star except for further development of wing-pads and Second ATymphal Itistar.—Length, 1.16-1.41 mm.; pale area within each lateral vitta on mesonotum. Avidth, 0.77-0.85 mm. Form elongate-oval somewhat narrowed posteriorly. Head strongly declivent, front Peribalus limbolarius Stal A'ertical, quite convex. Lateral margins of head First Nymphal Instar.—Length, 0.88-1.24 mm.; deeply sinuated and with distinct protuberances before Avidth, 0.81-0.94 mm. Newly hatched nymphs almost eyes. Juga and tylus form almost continuous curve at circular in outline, gradually becoming oval. Head front of head. Head and thoracic nota, in general, strongly deflexed, lateral margins oblique, not sinuate pale castaneous with pale pubescence and nearly before eyes. Tylus exceeds juga, which are rather concolorous punctures. Head more densely punctate acute apically. Head, thorax, and plates dark oliva- than thoracic nota, latter with four darker longitudinal ceous-brown to fuscous, shining, impunctate but with vittae and pale impunctate median line; lateral mar- sparse, pale hairs. Antennae castaneous, ratio of gins somewhat expanded, pale, impunctate, entire. lengths of segments approximately 5:6:5:15. Lateral Posterior margin of mesothorax strongly arcuated on thoracic margins entire, arcuated, not deeply notched 332 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 DECOURSEY AND ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 333 at sutures. Tergum of abdomen, aside from plates, junction of prothorax and mesothorax. Tergum of orange to reddish, impunctate but punctures may be abdomen as in preceding instar except more densely seen through transparent skin of individuals about to punctate, largest lateral plates contain about 50 punc- molt. Anterior pairs of lateral plates, except first, tures each. Pseudosutures represented by a sulcus greatly elongated, being twice as long as wide, inner running lengthwise of each lateral plate. One fuscous ends somewhat irregularly truncated. Median plates sclerotized area still present anterior to first gland- placed close together and with two narrow, fuscous, bearing median plate, the former anterior sclerotized sclerotized areas anterior to first gland-bearing plate. area now represented by a single row of rather closely Ventral surface of head pale. Pleura and legs in- spaced punctures. Ventral surface as in preceding fuscated but usually somewhat paler than thoracic instar except medioventral plates now have greater nota; tibiae not perceptibly sulcated. Venter con- longitudinal dimension. Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 colorous with dorsum, medioventral plates forming Fourth Nymphal Instar.—Length, 2.5-3.7 mm.; rather indefinite oval area with one end at anus. width, 1.9-2.8 mm. Form elliptical. Dark and pale Ventral portion of lateral plates only half as long as color forms now becoming more pronounced. Head dorsal portion, inner ends oblique. Spiracles and strongly deflexed. Juga sinuate, broadly rounded at spiracular punctures infuscated, circular, outer row apex, exceeding tylus. Ratio of lengths of antennal of spiracular punctures not yet present. segments approximately 15:30:27:45. Pubescence of Second Nymfilial Instar.—Length, 1.06-1.48 mm.; head and dorsum less pronounced than in preceding width, 0.O5-1.20 mm. Form broadly oval to oval, instars. Disk of thoracic nota most often entirely broadest at posterior extremity of mesonotum. Head fuscous to piceous but may contain pale pattern vary- still strongly deflexed. Lateral margins of head now ing from pair of minute whitish spots on mesonotum somewhat sinuated, juga and tylus equal in length. to extensive three-pronged pale castaneous area ex- Ratio of lengths of antennal segments approximately tending from head to posterior margin of mesonotum. 8:10:8:20. Head and thoracic nota dark castaneous Tergal plates separated by impunctate strips of to bronzy, clothed with soft whitish pubescence except bright vermilion red, those between median plates apex of head and lateral margins of pronotum, which interrupted by median section of pure white, lateral are pale. Tergum of abdomen as in preceding instar extremities of red interstices between lateral plates except for presence of punctation. Entire dorsum now also pale. Tergum of abdomen, aside from plates, now punctate, large lateral plates containing about 15 nearly white, densely punctured with fuscous and in- punctures each. Median plates punctate both anterior terrupted by red sutures. Pseudosutures represented and posterior to glandular slits, which are now paler by sulcus running lengthwise of lateral plates as in and more conspicuous than in preceding instar. Only preceding instar. Ventral side of head and pleura one sclerotized area now present anterior to first usually fuscous, punctate, but may be stramineous in median plate. Tergum of thorax, including plates, pale color forms. Infuscation of legs, antennae and with pale pubescence as on head and thoracic nota. rostrum also varies according to color form but apex Color pattern of ventral surface similar to that of of rostrum and apical segment of antennae usually preceding instar except for a few individuals which considerably infuscated. All of body, except head, have ventral surface of head and pleura completely with white margin beneath. Lateral plates, aside from fuscous. In these individuals the legs and all or part pale margin, and mediodorsal plates, may vary from of apical antennal segment are also more deeply in- pale to almost piceous. Remainder of venter pale with fuscated. Tibiae sulcated. Outer row of spiracular fuscous punctures and reddish flecks. punctures now present and medioventral plates clearly Fifth Nymphal Instar (fig. 9).—Length, 4.2-5.5 defined. mm.; width, 4.0-4.7 mm. Form oval to broadly oval. Third Nymphal Instar.—Length, 1.75-2.55 mm.; Head (fig. 10) as in preceding instar except tips of width, 1.45-2.10 mm. Form broadly oval to elliptical. juga now almost contiguous before tylus. Ratio of Head strongly deflexed, margins arcuated, very little lengths of antennal segments approximately 20:42: sinuated or not at all, juga slightly exceeding tylus. 39:56. Thoracic nota as in preceding instar except Apex of head usually concolorous with front and for greater development of scutellum and wing-pads, vertex. Antennae pale to fuscous; ratio of lengths of the former attaining the posterior margin of the antennal segments approximately 10:17:15:32. Head, metanotum and the latter extending to the third or thoracic nota, and plates still pubescent but pubescence fourth abdominal tergite. Color markings, etc., on shorter in proportion to size of insect. Margins of tergum as in preceding instar. In pale color forms thoracic nota and terga of abdomen pale and im- the thoracic nota may be almost entirely castaneous punctate in about half of individuals. Thoracic mar- and margins of median and lateral plates indefinite. gins entire, slightly arcuated, not deeply notched at Pubescence still present but relatively short and in-

PLATK 1.—Nymphs of Pentatomidae. FIG. 1.—Euschistus variolarius (P. de B.), fifth instar; tergal color pattern omitted. FIG. 2.—Mormidca lugens (Fabr.), fifth instar. FiG. 3.—Coenius delius (Say), fifth instar. FIG. 4.— Mcncclcs inscrtus (Say), first instar. FiG. 5.—Mcnecles insert us (Say), second instar. FiG. 6.—Menccles insertus (Say), fifth instar. FiG. 7.—Trichopepla semivittata (Say), fifth instar; insert shows antennae and color pattern of head. FIG. 8/—Xcottiglossa sulcifrons Stal, fifth instar; insert shows detail of head and antennae. 334 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 conspicuous. Entire ventral surface now pale ochrace- exceeding length of plates, between second and third, ous but with fuscous punctures. Antennae with at crescentic white bar caudad of third, longer than least the last two segments fuscous and likewise the preceding bar. Remainder of tergum usually piceous two distal segments of the rostrum. Legs concolorous but sometimes dull green with darker green blotches with pleura except tibiae and tarsi, the tibiae being and sutures, impunctate. Pleura and ventral side of variously infuscated and tarsi fuscous. Spiracles head fuscous to piceous, impunctate. Sternum, coxae, fuscous and usually conspicuous but spiracular punc- trochanters, and sometimes femora, pale, remainder tures much less so. of legs fuscous to piceous; tibiae sulcate. Venter as in preceding instar except series of median plates now Pitedia persimilis (Horvath) well defined. Spiracles and spiracular punctures lo-

First Nymphal Instar (fig. 11).—Length, 1.35-1.95 cated inside white border, almost concolorous with Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 mm.; width, 1.10-1.40 mm. Form oval to elliptical, background. becoming more elongate during latter part of instar; Third Nymphal Instar (fig. 13).—Length, 2.75-4.0 widest at second pair of lateral plates. Head and thor- mm.; width, 2.2-3.1 mm. In nearly all respects identi- acic nota fuscous, impunctate, finely rugose. Rounded cal with preceding instar. Tylus and juga about equal pale spot on vertex, extending across thoracic nota in length. Ratio of lengths of antennal segments ap- as a narrow median stripe. Head strongly declivent. proximately 9:22:15:23. Thoracic nota usually Tylus broadly rounded, with a very few short hairs piceous, but occasionally fuscous. Terg-um of abdomen at apex, margins of head feebly sinuate. Antennae now pale green with sutures and minute flecks of dark dusky at first, becoming mahogany; ratio of lengths green, replacing piceous portion in preceding instar. of segments approximately 5:7:6:13. Lateral margins White marking between first and second median of thorax not appreciably expanded, rather deeply plates, an oval spot. Some of white markings tinged notched between pronotum and mesonotum, the mar- with green. Number of punctures on lateral plates gins of which are arcuated. Tergum of abdomen about 9 to 12. mostly shining dark olivaceous but with first three Fourth Nymphal Instar.—No specimen available. tergites of abdomen pale yellow cephalad of anterior Fifth Nymphal Instar.—Length, 8.2-9.7 mm.; median plate and ending in lobes of same color which width, 6.7-7.4 mm. Form oval to broadly oval. Head flare out caudad and are terminally cleft. Median moderately declivent, juga equal to tylus. Margins of plates surrounded by broad margin of pale yellow, head sinuate before eyes, reflexed, sometimes thinly the latter color also occupying the interstices between edged with fuscous. Head pale green with fine fuscous the lateral plates. Median plates concolorous with punctures, finely rugose. Basal segment of antennae notum of thorax, ends of second and third plates green, sometimes somewhat infuscated, other seg- bevelled off to an angle of about 110°. Lateral plates ments fuscous. Ratio of lengths of antennal segments rather short, with inner ends rounded, except for first, approximately 17:57:37:40. Thoracic nota and wing- which is triangular and very small. Pale lateral mar- pads concolorous with head, except expanded lateral gin present around abdomen, dividing each lateral margins, which are shell pink to rosaceous, with more plate into dark and pale portions. Ventral surface or less obsolete punctures of same color, entire, mostly concolorous with corresponding dorsal sur- slightly arcuate. Tergum of. abdomen about same face. Legs castaneous to fuscous, tibiae sulcated. color as thoracic nota but with rounded, slightly Lateral plates on venter parallelograms, the anterior sunken blotches of darker green, somewhat larger inner angle being obtuse. Abdomen with pale lateral than punctures on head and thoracic nota. Margin of margin as on dorsum except lateral plates are shorter abdomen of same color as that of thorax, dividing and do not extend beyond pale margin. lateral plates. Apical portion of lateral plates variable, Second Nymphal Instar (fig. 12).—Length, 1.85- contain many minute punctures which may or may 2.50 mm.; width, 1.70-1.95 mm. Form broader than not be infuscated. Median plates vary in color from preceding instar. Young individuals broadest at stramineous, through green, to fuscous, but always mesothorax whose width is eventually exceeded by with fuscous puncture before and behind glandular that of abdomen. Head and notum now piceous and slit; rugose, calloused white about glandular open- deeply punctate except margins of notum, which are ings. Ventral side and legs, except tarsi and apex of now expanded white and obsoletely punctate. Lateral rostrum, green, these latter infuscated to fuscous. margins of head reflexed, deeply sinuate before eyes. Pleura and head sparsely punctured and venter Tylus still exceeds juga and bears a few short bristles. rather sparsely blotched. Setae on tibiae castaneous Margins of pronotum and mesonotum denticulate, not and not set in dark spots, tibiae sulcated. Median ven- arcuated. Lateral margins of abdomen now conspic- tral plates concolorous with venter but more shiny. uously margined with white but somewhat more nar- rowly so than notum. Lateral plates now mostly Thyanta custator (Fabricius) white, apical portions triangular, piceous, punctate. First Nymphal Instar.—-Length, 0.88-1.06 mm.; Pale area on first three tergites much as in preceding width, 0.71-0.84 mm. Form elliptical. Tylus somewhat instar but median plates no longer bordered laterally truncated, bears a few hairs, exceeds juga. Lateral by pale markings, short bar or elongate spot of white margins of juga oblique, very slightly arcuated. Head between first and second plates, straight bar of white, strongly declivent, almost vertical. Eyes, as seen from DECOURSKY AXD ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 335 front, about twice as long as wide. Ratio of length of margins of thoracic nota white or pale yellow, with antennal segments approximately 7:10:8:17. Head very thin fuscous, serrulate border and a few obsolete thorax fuscous to piceous, lateral margins of thorax punctures. Metanotum still somewhat depressed but not much expanded. Tergum of abdomen shiny cas- less so than in preceding instar. Pubescence on head taneous in living specimens, with median and lateral and thoracic nota as in preceding instar. Tergum of plates concolorous with head and thoracic nota. Two abdomen with conspicuous white bars which strike oblong diagonal white spots extend across second and margin between lateral plates, first ones bending third tergites. First median plate perceptibly longer cephalad in crossing disk, two passing between median than second and third, these latter bordered at ends plates. Tergum, except plates, impunctate. Median by emarginate lemon-yellow areas in which the inter- plates with a single dense row of minute but deep vening sutures stand out very plainly. First pair of punctures just inside margins and a few scattered ones Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 lateral plates very minute, followed by largest pair, inside. Lateral plates usually with bar of paler color whose inner margin is a parabola. Transverse dimen- just inside margin of abdomen, punctures in darker sion of lateral plates diminishes from second pair portions; a few, mostly marginal, setae present, some posteriorly. Ventral surface, rostrum and legs mostly as long as the plate itself. Ventral surface in general castaneous. somewhat paler but sometimes fuscous, venter pale Second Nymphal Instar.—Length, 1.16-1.84 mm.; castaneous to stramineous, median spots sometimes width, 0.°<5-1.34 mm. Form ovate to elliptical, widest not evident, pleura with a few punctures. Ventral at mesothorax. Strongly constricted dorsoventrally portion of lateral plates smaller than dorsal portion, at metanotum, being almost antlike in appearance, inner margins truncate to somewhat concave. Spir- becoming less so as abdomen becomes more distended. acles pale. Legs with setae of about same color, tibiae Antennae almost as long as body, ratio of lengths of broadly and rather shallowly sulcated. Rostrum con- segments approximately 6:10:8:14. Lateral margins colorous with ventral surface except apical segment, of thorax strongly expanded, serrulate and deeply which is usually somewhat more infuscated. notched at junction of pro- and mesonotum. Head Fourth Nymphal Instar.—Length, 3.1-4.6 mm.; and thoracic nota with rather long, pale pubescence. width, 2.8-3.2 mm. Form broadly oval. Head may be Color pattern as in previous instar but expanded entirely fuscous in individuals of dark color form, lateral margins of thorax usually yellowish. Head, but otherwise with juga and apical portion of tylus thoracic nota, and plates definitely punctured except much paler. Ratio of lengths of antennal segments notal margins, where punctures are obsolete, plates approximately 10:24:19:23, second segment with pale sparingly punctured. Ventral surface of head and dorsal vitta running almost entire length. Pubescence pleura castaneous, pleura with a few deep punctures. on head and thoracic nota more sparse and metanotum Venter concolorous with tergum, median plates may less depressed than in preceding instar. Pale bars on he rather indistinct. Lateral plates similar to dorsal lateral plates more evident. Lateral plates on venter portion but somewhat shorter and more truncated. pale except in individuals of dark color form, in Third Nymphal Instar.—Length, 1.8-3.2 mm.; which case margins of plates are dark. Other char- width, 1.6-2.5 mm. Form oval to pyriform, distended acters as in preceding instar. individuals widest at third pair of lateral plates, Fifth Nymphal Instar (fig. 14).—Length, 4.4-8.2 others at mesothorax. Head declivent, castaneous in mm.; width, 3.7-5.9 mm. Ratio of length of antennal younger individuals, gradually becoming fuscous, sin- segments approximately 14:38:27:30. Form and uated before eyes, tylus rounded, slightly exceeding coloration much as in preceding instar except for juga. Ratio of length of antennal segments approxi- further development of wing-pads; lateral plates now mately 8:16:12:1(). Kyes no longer linear in cephalic all pearly with heavy dark margin. view. Head and thoracic nota punctate, in the main fuscous. Head may be entirely fuscous or with juga Cosmopepla bimaculata (Thomas) and anterior portion of tylus bright amber with First Nymphal Instar.—Length, 0.88-1.05 mm.; fuscous punctures and thin fuscous margin. Thoracic width, 0.71-0.88 mm. Form oval, broadest at second nota fuscous with somewhat varied pattern of white pair of lateral plates. Head rather strongly declivent. or bright amber or both. Paired white spots on disk Margins of head oblique, tylus exceeds juga and has of mesonotum and metanotum apparently always pres- a few rather conspicuous pale setae. Ratio of lengths ent, those on mesonotum larger and apparently com- of antennal segments approximately 6:5:5:14. Color posed of two confluent spots each. Usually present of head, thorax and plates olivaceous to bronzy or are two still larger and more angular white spots at even fuscous. Lateral thoracic margins not expanded, anterior margin of pronotum, these usually connected posterior margin of metathorax straight. Lateral by an amber area so as to form an ornate "T," the plates nearly triangular, inner apex rather acute. stem of which is formed by a rather broad median Median series of plates usually consisting of seven in amber vitta extending to posterior margin of meso- all, two anterior and two posterior to the three that thorax. When "T" is present, another pair of white bear glandular openings. Glandular plates gradually spots adjacent to stem of "T" completes a transverse diminish in length from anterior to posterior but the row of four white spots on mesonotum. Spots may be ostioles themselves are not more widely separated in calloused white or with fuscous punctures. Lateral the anterior plates. Abdominal tergum, aside from 336 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55

plates, dull yellow to dull orange. Ventral surface tained posterior margin of metathorax. Color on concolorous with dorsum throughout. Rostrum, an- abdomen of various individuals varies from tomato- tennae, and legs concolorous with head and thorax. red to nearly white. Other characters as in preceding Median plates not clearly defined. Both dorsal and instar. ventral surfaces impunctate. Fifth Nymphal Instar (fig. 15).—Length, 3.4-4.2 Second Nymphal Instar.—Length, 1.11-1.48 mm.; mm.; width, 2.9-3.4 mm. Form as in preceding instar. width, 0.71-1.13 mm. Form somewhat more elongated Juga now approximately equal to tylus. Head in than in preceding instar. Tylus still exceeds juga, same position as in preceding instar. Pattern of cas- lateral margins of head only very slightly sinuated. taneous now on all individuals and developed to point Ratio of lengths of antennal segments approximately where it exceeds fuscous. Wing-pads now reach pos-

7:8:8:17. Head and thoracic nota colored as before terior margin of third abdominal tergite. Fuscous Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 but with a few sparse, minute punctures. Lateral portion of first mediodorsal plate consists of large thoracic margins unchanged but posterior margin oval spot at each extremity. Lateral plates as in pre- now rounded off at lateral extremities. Abdomen, ceding instar but with 18 to 20 punctures each. Ven- above and below, tomato-red in color with the excep- tral surface mostly castaneous but juga and pleura tion of the plates and spiracles and now bearing a few considerably infuscated, latter also punctate. Legs en- rather large, conspicuous, fuscous punctures. Lateral tirely fuscous, tibiae shallowly sulcated. Medioventral plates as in preceding instar except inner apex is plates fuscous, clearly defined. Lateral plates on ven- now more rounded and each plate bears three or four ter narrow, broadest at posterior end. Inner spiracular punctures. Median plates likewise bear punctures, puncture equal in size to spiracle. Other characters as both before and behind slit, the two plates anterior to in preceding instar. first glandular plates now less evident. Ventral sur- Oebalus pugnax (Fabricius) face concolorous with dorsum except meso- and meta- pleura do not quite reach lateral margin, being sep- First Nymphal Instar.—Length, 1.12-1.21 mm.; arated from notal margin by narrow strip of tomato- width, 0.82-0.85 mm. Form elliptical, may be broadest red ; pleura with a very few punctures. Legs, antennae, at mesonotum during latter part of instar. Orange- and rostrum concolorous with head and thorax. Tibiae red and castaneous or fuscous in color. Head strongly not sulcated. Spiracles fuscous, elevated, located in declivent. Tylus exceeding juga by nearly its width emargination at anterior margin of inner apex of and adorned by a few golden hairs at apex. Antennae lateral plate. Medioventral plates sometimes ill-de- mahogany red, with minute brownish hairs; ratio of fined. lengths of antennal segments approximately 4:4:4:9, Third Nymphal Instar.—Length, 1.64-2.27 mm.; apical segment stouter, fusiform. Head and thoracic width, 1.38-1.66 mm. Form broadly oval. Head nota castaneous to fuscous, impunctate, lateral thor- rather strongly declivent. Tylus exceeds juga. Lateral acic margins not much expanded. Tergum of abdomen margins of head more deeply sinuated than in pre- orange-red, with castaneous lateral and median plates. ceding instars. Juga rather finely rugose, punctures Suture and pseudosutures usually not readily discern- on head shallow. Ratio of length of antennal segments ible. Median plates of equal length, posterior two approximately 9:11:11:23. Thoracic nota now subelliptical, anterior one more elongate and grad- fuscous, more densely punctate than in preceding in- ually constricted at median line. Lateral plates some- stars. Thoracic margins as in preceding instars. what semicircular except anterior pair, which are Lateral plates as before except number of punctures more angular and less than half as large as next now about eight or nine per plate. Median plates as pair. Ventral surface of head and thorax paler than in preceding instar except the two plates anterior to dorsum. Rostrum with proximal segment concolorous first glandular plate have now disappeared or are at with ventral surface, remainder concolorous with most reduced to a row of confluent fuscous punctures. thoracic nota. Inner surface of fore tibiae with spur- Characters on ventral surface as in preceding instar. like structure of two close-set setae at two-thirds Tibiae little if at all sulcated. distance to apex. Venter concolorous with tergum and Fourth Nymphal Instar.—Length, 2.0-3.0 mm.; with somewhat infuscated indefinite area on posterior width, 1.8-2.6 mm. Form broadly oval to circular, dor- portion of disk. Lateral plates on venter with ends sum very convex. Head strongly declivent. Tylus diagonal, posterior side longer. Spiracles elevated, slightly exceeds juga. Lateral margins of head mod- deep red, inner spiracular punctures similar to outer, erately sinuated before eyes. Ratio of lengths of an- but much smaller, outer puncture barely perceptible tennal segments approximately 12:20:18:32. Rather at 75x magnification. complex castaneous color pattern present on pro- and Second Nymphal Instar.—Length, 1.66-2.40 mm.; mesonotum of many individuals. Wing-pads have at- width, 1.06-1.55 mm. Form oval to elongate oval,

PLATE 2. Nymphs of Pentatomidae. FIG. 9.—Peribalus limbolarius Stal, fifth instar. FIG. 10.—Peribalus limbo- larius Stal, fifth instar, head showing color pattern. FIG. 11.—Pitedia persimilis (Horvath), first instar. FIG. 12.— Pitedia persimilis (Horvath), second instar. FIG. 13.—Pitedia persimilis (Horvath), third instar. FIG. 14.— Thyanta custator (Fabr.), fifth instar. FIG. 15.—Cosmopepla bimaculata (Thomas), fifth instar. DECOURSF.Y AND ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 337 Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021

4855* 338 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 some individuals twice as long as wide; very convex head mostly stramineous but may have fuscous areas dorsally. Head and thorax, except thoracic margins, caudad of antennal sockets. Rostrum pale at base, shiny, somewhat bronzy black. Head almost im- becoming increasingly infuscated apically. Lateral punctate. Tylus exceeding juga by only slightly less portion of pleura fuscous to black, with sharp line of than width of tylus. Juga finely rugose, margins re- demarcation between it and pale portion; pigment flexed. Antennae dark mahogany, with reddish an- may extend one-half distance to median line. Venter nul i, somewhat more pubescent than in preceding as in preceding instar. instar; ratio of lengths of segments approximately 6:10:9:14. Thoracic nota finely and sparsely punc- Acrosternum hilare (Say) tured, expanded margin white, impunctate, entire. First Nymphal Instar.—Length, 1.60-2.05 mm.;

Tergum of abdomen whitish, with scarlet sutures and width, 1.15-1.75 mm. Form oval, broadest at second Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 pseudosutures, connected by scarlet cross-bars, mostly pair of lateral plates. Head shining, impunctate, cas- scarlet between median plates. Median plates as in taneous except vertex, moderately declivent, margins preceding instar except ends of anterior one more oblique, tylus exceeding juga, somewhat angulate api- acute and second with anterior and posterior margins cally. First three antennal segments pale, apical seg- nearly straight and parallel. Lateral plates with inner ment darker, spindle-shaped, ratio of lengths of an- margin diagonal, longer on posterior margin than tennal segments approximately 7:14:13:27. Thoracic anterior; color fumose. Ventral surface of head and nota castaneous with poorly defined yellowish area thorax similar in color to dorsum, including white adjoining area of same color on vertex, or entire thoracic margins. Legs and rostrum concolorous with notum may be yellowish. Thoracic margins entire but head and thorax. Venter less barred than tergum. rather deeply notched at sutures. Tergum of abdomen Medioventral series of five fumose plates present. transversely striped with white and dull purple, the Lateral plates similar in shape and color to dorsal latter color being along the sutures and pseudosutures. portion. Spiracles and spiracular punctures fuscous. The purple color predominates on the disk, due to in- Third Nymphal Instar.—Not available. terruption of white lines from fourth and fifth pairs Fourth Nymphal Instar.—Length, 3.2-5.1 mm.; of lateral plates; these lines present, however, along- width, 2.0-2.8 mm. Ratio of lengths of antennal seg- anterior and posterior margins of median plates, ments approximately 10:22:18:21. Dark and pale which are of approximately equal length. All plates forms now exist. Dark form similar to preceding in- fuscous, lateral ones triangular with inner apices stars, pale form with head and disk of thoracic nota rounded off. Under side of head and thorax yellowish. stramineous with rather sparse fuscous punctures, Rostrum beyond middle of second segment castaneous. heavily infuscated just inside white margin. Tylus Legs castaneous to tarsi, which are yellowish, tibiae impunctate, juga with thin margin of fuscous, pale on sulcated. Venter yellowish, becoming dilute purplish. median line. Lateral plates of both forms whitish with In younger specimens ventral segments show as bars rather heavy fuscous margins. Tergum of abdomen extending nearly to lateral plates but with sutures impunctate. Other characters as in second instar. pale. Ventral portion of lateral plates equal in size to Fifth Nymphal Instar (fig. 16)—Length, 4.7-8.6 dorsal portion but inner apex acute and directed some- mm.; width, 3.0-4.1 mm. Form elongate-oval. Juga what caudad. Spiracles and spiracular punctures equal to tylus, finely rugose. Degree of pigmentation somewhat infuscated, but only inner row of latter of head varied but tylus and remainder of median line present. of head pale, tylus with few or no punctures. Juga Second Nymphal Instar.—Length, 2.30-3.18 mm.; sometimes entirely fuscous or black, but at least with width, 1.95-2.33 mm. Form broadly oval, broadest fine, fuscous punctures and thinly margined with point as in previous instar. Head and disk of thoracic fuscous or black. Antennae fuscous to black, ratio of nota piceous, coarsely and deeply punctate. Head in lengths of antennal segments approximately 11:34: same position as in preceding instar but margins now 25.27. Thoracic nota and wingpads with varying sinuate, juga equalling tylus. Antennae fuscous with amount of dark pigment but pale and impunctate on white incisures, less stout than in preceding instar, median line, size of punctures and density of pigmen- ratio of lengths of antennal segments approximately tation increasing laterally until solid black border 7:17:14:23. Margins of thorax strongly explanate, is formed just inside white lateral margin. Trans- denticulate, those of pronotum and mesonotum bright lucent white lateral margin extends to apical one- orange-yellow. Tergum of abdomen as in preceding fourth of wing-pads. Wing-pads mostly fuscous to instar except that lateral and median plates are now black but with at least a small pale area on disk. Ter- punctate, the median plates being punctate both an- gum of abdomen varies from barred effect of earlier terior and posterior to glandular slit. Ventral surface instars, through roseate, to stramineous. Median generally dark, except lateral thoracic margins, which plates fuscous to black except being more or less pale are bright orange-yellow as above. Ventral surface of along median line and about glandular openings. head and pleura fuscous; legs also fuscous, except Lateral plates as in preceding instar but pale portion tarsi which are sometimes pale. Tibiae with broad, forming band continuous with and of same width as shallow sulcus and greatly flattened. Venter usually that on thorax and wing-pads. Entire tergum of abdo- purplish except plates, which are fuscous, the lateral men, including plates, impunctate. Ventral surface of plates usually thinly margined with white. Medio- 1962 DKCOI'RSEY AND ESSKLBAUGH: NYMPHAL STAGES OF SOME PENTATOMIDAE 339 ventral plates of moderate size, more dilute fuscous largely green but may be pigmented with deep red than lateral plates, which are emarginated on anterior about median plates. Ventral surface almost uni- side to receive spiracles. formly pale green but lateral plates may have varying Third Nymphal Instar.—Length, 4.0-5.2 mm.; amounts of piceous. Rostrum usually green, except width, 2.0-4.4 mm. Form broadly oval, broadest as extreme apex, which is fuscous, and with a row of in preceding instars. Head also little changed but short pale hairs each side of labial groove. Legs juga may be castaneous in some individuals. Ratio of vary from green to fuscous but tarsi are most often lengths of antennal segments approximately 10:28:- fuscous. Tibiae sulcated. 22:28. Pale color forms now becoming evident. Thoracic nota may be piceous except for orange Podisus maculiventris (Say) margins, as in preceding instar, or with varying First Nymphal Instar.—Length, 1.15-1.60 mm.; Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 amounts of castaneous on disk, particularly of the width, 0.90-1.35 mm. Form broadly oval to almost mesonotum, to almost entirely castaneous. Tergum circular. Head considerably deflexed, fuscous, im- of abdomen much as in preceding instar but purplish punctate, margins not sinuated before eyes, tylus ex- sutures and pseudosutures now narrower and less ceeds juga. Antennae concolorous with head, ratio distinct and white portion has now become tinted of length of segments approximately 7:12:11:18, with greenish. Ventral side not constant in colora- with sparse, pale pubescence, terminal segment tion, being either yellowish or greenish and with rather acute apically. Thoracic nota fuscous, im- varying amounts of fuscous. Lateral plates more punctate, lateral margins rather deeply and acutely nearly semicircular than in preceding instar. notched at sutures between nota but otherwise en- Fourth Nymphal Instar.—Length, 6.8-8.2 mm.; tire. Tergum of abdomen usually tomato-red in fresh width, 5.5-6.7 mm. Form broadly oval. Basal seg- specimens, impunctate, with fuscous to black median ment of antennae, and sometimes the proximal por- and lateral plates. One or two narrow, fuscous, tion of second, green; remainder fuscous. Ratio of chitinized areas usually present between mctanotum lengths of antennal segments approximately 13:40:- and anterior median plate, which is rather strongly 32:40. No morphological changes from preceding in- constricted at median line and is slightly longer than star except customary change in posterior margin the second plate, which is roughly trapezoidal in of mesonotum, but general coloration of tergum of shape. Third median plate similar in shape to second abdomen has become apple-green with streaks of but appreciably smaller and followed by two succes- fuscous or dark purple. Ventral surface pale. Ros- sively smaller, fuscous, sclerotized areas. Lateral trum only slightly infuscated except at apex, which plates oblong, second and third pairs about twice as is entirely fuscous. Legs green to tibiae, latter and long as wide. Ventral surface corresponds to dorsuni tarsi fuscous. as to color pattern, but infuscation sometimes con- Fifth Nymphal Instar (fig. 17).—Length, 10.0-12.7 siderably diluted. Rostrum and legs infuscated in mm.; width, 7.5-9.4 mm. Form elongate-oval to oval. varying degrees but tarsi usually somewhat paler, Head rather porrect, broadly rounded anteriorly, juga tibiae broadly and shallowly sulcated. Rostrum stout, and tylus of equal length. Margins of head sinuated much flattened, bucculae undeveloped, leaving basal before eyes, paralleling each other for a short dis- segment free. Spiracle and spiracular puncture of tance. Tylus and juga rugose, punctation very fine each abdominal segment located in separate emargina- and inconspicuous. Coloration of head varies widely, tions of lateral plates. No medioventral plates ranging from entirely green to piceous and with discernible. jugal margins orange yellow. Antennae mostly fus- Second Nymphal Instar.—Length, 1.75-2.95 mm.; cous to piceous except basal segment and sometimes width, 1.40-2.05 mm. Form broadly oval to oval. part of second, which are clear green to slightly in- General color as in preceding instar. Head mod- fuscated but in pale forms only the distal half of the erately deflexed, rather finely punctate, tylus fre- last two segments may be fuscous. Ratio of lengths quently more or less impunctate apically, margins of antennal segments approximately 18:60:48:50. sinuated before eyes, juga equal to tylus. Basal Thoracic nota also vary widely in amount of piceous segment of antennae concolorous with head, second with pale discal areas on pro- and mesothorax as and third usually pale, fourth somewhat darker, ratio in preceding instar. Wing-pads more prone to be of lengths of segments approximately 9:25:18:28. piceous than other parts. Punctation very minute, Eyes sanguineous. Thoracic nota rather finely punc- almost invisible except on pale areas. Orange thoracic tate, lateral margins serrulate, more expanded than margins present only on dark color form. Tergum in preceding instar. Metanotum attains lateral mar- of abdomen impunctate except for lateral and median gin of insect and has short but distinct, serrulate, plates, which are finely punctate over entire surface. lateral margin. Tergum of abdomen as in preceding Median plates also rugose anterior to glandular slit. instar except there is only one minute, fuscous, Plates resemble head and thoracic nota as regards ex- chitinized area anterior to first mediodorsal plate and tent of piceous pattern, being most often piceous but all plates are punctate, largest lateral plates contain- in pale color forms may be almost concolorous with ing about 20 punctures each. Mediodorsal plates remainder of tergum. Intermediate forms have por- punctate before. and behind glandular slit. Pleura tion of plates piceous. Tergum other than plates and under side of head impunctate, fuscous. Ros- 340 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55 trum and legs fuscous, except tarsi which are strami- thoracic margins more coarsely dentate, wing-pads neous, tibiae sulcated. Venter concolorous with ter- and scutellum much more developed. Tergum of ab- gum; series of oblong, fuscous, medioventral plates domen as in preceding instar. Ventral surface mostly now clearly defined. Lateral plates impunctate on as in preceding instar. Rostrum pale to slightly in- ventral portion, inner end with two emarginations, fuscated. Legs vary in coloration from pale to almost anterior emargination containing the spiracle and piceous. Narrow piceous margin about entire body, posterior one the two spiracular punctures, the outer including head. Remainder of ventral surface pale, of which is half on the plate and half outside. lateral plates, exclusive of outer margins, usually Third Nymphal Instar.—Length, 2.6-4.3 mm.; nearly concolorous with venter. Tarsi still usually width, 1.8-3.1 mm. Form oval to broadly oval. Head paler than tibiae. fairly porrect, margins somewhat sinuated before eyes, Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 juga parallel for an appreciable distance and broadly Perillus bioculatus (Fabricius) rounded in front, slightly exceeding tylus in older First Nymphal Instar.—Length, 1.02-1.37 mm.; specimens. Coloration and punctation of head and width, 0.95-1.09 mm. Form oval to broadly oval. thoracic nota much as in preceding instar but in General color fuscous except tergum of abdomen, some individuals have a bronzy appearance or are sternum and venter, which are tomato-red, entirely somewhat mottled. Ratio of lengths of antennal seg- impunctate. Head strongly deflexed, margins sinuated ments approximately 10:37:30:35, apical segment before eyes. Antennae reddish-brown with reddish very little dilated. Lateral thoracic margins as in annuli at joints, apical segment thicker, subcylindri- preceding instar except extremities of metanotum cal, abruptly tapered at apex. Ratio of lengths of an- gradually become covered by mesonotum and appear tennal segments approximately 10:10:9:21. Lateral not to reach lateral margins of insect. Tergum of thoracic margins not expanded, those of each sclerite abdomen orange to whitish, sutures and pseudosutures being somewhat arcuated, forming a crenate margin. broadly margined with red, the red also persisting Lateral plates longer than broad, somewhat tapered, about median plates except for short transverse bars apical and narrowly rounded. Median plates gradually of white between first and second plates, becomes decrease in length posteriorly, glandular openings of arcuated cephalad on disk of tergum. A well-de- first plate slightly farther apart than those of second veloped fourth fuscous plate occurs on the suture and third plates, no pale area contiguous to openings between the sixth and seventh tergites and a smaller but red interior visible in ostioles. Pleura, ventral one on the eighth tergite, its two ends nearly con- side of head, rostrum and legs castaneous to fuscous. tiguous with lateral plates on that tergite. All punc- Lateral plates on ventral side smaller than dorsal tures occur on the heavily sclerotized, fuscous plates, portion, ending in an asymmetrical tooth. Spiracles those on median plates occurring both anterior and fuscous, located in shallow emargination on anterior posterior to slit, the latter crossing the plate near the side of lateral plate. One spiracular puncture per middle. segment visible, fuscous, located mesad and caudad Fourth Nymphal Instar.—Length, 3.4-5.8 mm. ; of apex of lateral plate. No medioventral plates width, 2.7-4.0 mm. Form oval to broadly oval. Little discernible. change, except in size, from preceding instar. Ratio Second Nymphal Instar.—No specimens available. of lengths of antennal segments approximately 8:30 :- Third Nymphal Instar.—Length, 2.3-3.2 mm.; 20:23. Paler individuals have pair of large, yellowish, width, 2.0-2.8 mm. Form broadly oval. General rather angular spots on pronotum and frequently a color as in first instar except that head, thoracic nota similar or smaller pair on mesonotum and juga may and plates are now dark, metallic blue and very finely also be pale. Lateral thoracic margins finely dentate. punctured. Head moderately declivent, lateral mar- Wing-pads extend to posterior margin of mesonotum. gins moderately sinuated before eyes, juga broadly Largest lateral plates (dorsal portion) contain about rounded apically and equal to tylus. First two an- 50 small punctures. Median plates and entire ventral tennal segments concolorous Math head but last two surface as in preceding instar. becomingly progressively paler, the apical one reddish- Fifth Nymphal Instar (fig. 18).—Length, 5.9-8.6 brown at apex, last two interstices pale. Ratio of mm.; width, 4.4-5.6 mm. Form elongate-oval. Head length of antennal segments approximately 7:18:- and thoracic nota now have extensive pattern of 14:21. Lateral margins of pronotum and mesonotum stramineous markings, lateral margins of head, entire but arcuated, extremities of metanotum hidden thoracic nota and wing-pads, median line of pro- beneath mesonotum. Tergum of abdomen red, impunc- notum and scutellum and posterior margin of pro- tate, all pairs of glandular openings equally remote notum having tendency toward darker coloration, and supporting plates of equal length, a few minute punctures on stramineous portion rufous. Lateral punctures before and behind each glandular slit.

PLATE 3. Nymphs of Pentatomidae. FIG. 16.—Oebalus pugnax (Fabr.), fifth instar. FIG. 17.—Acrostcrnum hilare (Say), fifth instar; insert shows lateral ventral plate and relative position of spiracle with bases of tricho- bothria. FIG. 18.—Podisus maadiventris (Say), fifth instar. FIG. 19.—Perillus bioculatus (Fabr.), fifth instar; upper insert shows ventral view of fore femur and tibia, lower insert shows lateral ventral plate and relative position of spiracle with bases of trichobothria. 1962] DECOURSEY AND ESSELBAUGH : NYMPHAL STAGES OF SOME PENTATOMIDAE 341 Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 342 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA [Vol. 55

Lateral plates rough but apparently impunctate. Ven- DuPuis, C. 1947. Formes preimaginales d'Hemipteres tral surface as in first instar except series of medio- Pentatomidae. I. Les nymphes des Asopinae. Bull. ventral plates now present on venter, diminishing in Soc. Ent. France 52: 54-57, 2 figs. size anteriorly, two spiracular punctures present on Esselbaugh, C. 1949. Notes on the bionomics of some midwestern Pentatomidae. Ent. Amer. [1948] 28 each sclerite posterior to third. (1/2) : 1-73. Fourth Nymphal Instar.—Length, 3.9-5.4 mm.; Guide, J. 1902. Die Dorsaldriisen der Larven der width, 2.9-3.7 mm. Form oval. Juga slightly exceeds Hemiptera-Heteroptera. Ein Beitrag zur Kenntnis tylus in some specimens. Ratio of lengths of antennal derselben. Ber. Senckcnburg. naturforsch. Ges. segments approximately 9:25 :20:22. Lateral thoracic [Frankfurt-a.-M.] 1902(2) : 85-132, 2 pis. margins reddish, broad anteriorly, tapering to point 1934. Die Wanzen Mitteleuropas (Hemiptera-Heter- optera. Pentatomidae. Tcil 3: 79-194. Frankfurt. at base of wing-pads. Large area of same color on Downloaded from https://academic.oup.com/aesa/article/55/3/323/138081 by guest on 27 September 2021 disk of pronotum in some individuals. Wing-pads Hart, C. A. 1919. The Pentatomoidea of Illinois, with keys to the Nearctic genera. Bull. Illinois Nat. Hist. reach posterior margin of metanotum. Fore femora Surv. 13(7) : 157-223, 6 pis. armed beneath at apical three-fourths with blunt Jordan, K. H. C. 1951. Bestimmungstabelle der tubercle. Familien von Wanzenlarven. Zool. Anz. 147: 24-31, Fifth Nymphal Instar (fig. 19).—Length, 5.9-8.4 4 figs. mm.; width, 4.5-5.6 mm. Form oval to elongate-oval. Kuhlgatz, Th. 1905. Beitrag zur Kenntnis der Meta- Head fairly porrect, lateral margins slightly sinuated morphose gefliigelter Heteroptercn. Zool. Jahrb. before eyes, parallel to each other for a short dis- Suppl. VIII (Festschr. Mobius) : 595-616. Leston, D., and G. G. E. Scudder. 1956. A k.'y to tance. Juga may equal tylus or slightly exceed it, larvae of the families of British Heteroptera. En- forming a broad apex. Color pattern of pronotum tomologist 89: 223-31. and wing-pads varies greatly in amount of pale color Miller, N. C. E. 1956. The Biology of the Heteroptera. present. Wing-pads extend to posterior margin of London: Leonard Hill, Ltd. 162 pp., 64 figs. second mediodorsal plate. Tergum of abdomen finely Puchkov, V. G. 1959. Larvae of Hemiptera-Heterop- punctate, reddish to nearly white, punctures of nearly tera belonging to the super-family Pentatomoidea. same color. Plates as in preceding instars except I. Identification keys of the families Pentatomoidea and of the species of Acanthosomidae, Cydnidae and lateral margin may be pale. Ventral surface mottled Scutelleridae. Zool. Zhur. 38: 1190-1206. [In to various degrees with fuscous and red or whitish. Russian.] Tubercle on under side of fore femora more pro- Puchkova, L. V., and V. G. Puchkov. 1958. Certain nounced than in preceding instar. Tibiae usually morphological peculiarities of the abdominal odor- with pale annulus at middle, broadly and shallowly iferous glands in Pentaiomidae larvae (Pentato- sulcated. Outer margin of dorsal lateral plates fre- moidea, Hemiptera-Heteroptera). No. 1. Dopovidi Akad. Nauk Ukrans'koi RSR 1958(1): 100-4. [In quently pale, posterior margins broadly rounded. Ukrainian.] Inner margin of ventral lateral plates with two Southwood, T. R. E. 1956. A key to determine the emarginations, the larger, anterior one containing the instar of an heteropterous larva. Entomologist 89: spiracle and the other the outer spiracular puncture, 220-2. which is contiguous to margin of plate (see inset Southwood, T. R. E., and D. Leston. 1959. Land and fig. 19). Venter inconspicuously but rather coarsely Water Bugs of the British Isles. London : Frederick punctate about lateral plates and much more finely Warne & Co., Ltd. xi + 436 pp., 63 pis. so on disk. Pseudosutures rather conspicuous on Tullgren, A. 1918. Zur Morphologic und Systematik der Hemipteren. I. t)ber das Vorkommen von s.g. venter, medioventral plates as in preceding instar. Trichobothrien bei Hemiptera-Heteroptera und ihre Bedeutung fur das Heteropterensytem. Ent. Tidskr. REFERENCES CITED 39: 113-33, 11 figs. Butler, E. A. 1923. A Biology of the British Hemip- Weber, H. 1930. Biologie der Hemipteren. Eine tera-Heteroptera. London: H. F. & G. Witherby. Naturgeschichte der Schnabelkerfe. Berlin: J. vi + 682 pp., 7 pis. Springer, vii + 543 pp. Notes on Neotropical Tabanidae (Diptera) III. The Genus Protosilvius Enderlein1 G. B. FAIRCHILD Gorgas Memorial Laboratory, Panama, Republic of Panama ABSTRACT The South Brazilian genus Protosilvius Enderlein P. phoeniculus, P. priscus, and P. mackerrasi are (Dipt., Tabanidae) is reviewed and Histriosilvius Kro- described from both sexes. The genus is considered ber placed in synonymy. The type species, P. termiti- to belong to the most primitive section of the Pangoniini, for mis End. and H. longipalpis (Macq.) of the respective near the Australian Ectcnopsis and Nearctic Apatolcstcs genera are redescribed and figured, and 3 new species, and Asaphomyia.

The knowledge of Protosilvius and Histriosilvius has hitherto depended entirely on the female type — specimens of the species on which they were founded. 1 Partial cost of publication of this paper was met by Gorgas Cf.lir1,, „{ rnncirWnhip iririirimvil mnrprini ii Memorial Laboratory. Accepted for publication November 15, 1961. otudy Ot considerable additional material, 11