Dunnius barpetensis Salini & Rabbani, 2023

Salini, Santhamma, Gracy, R. G., Akoijam, Romila, Rabbani, Mehaboob K., David, K. Jacob & Roca-Cusachs, Marcos, 2023, Revision of Acesines Stal and Dunnius Distant, resurrection of Mycterizon Breddin (Hemiptera, Heteroptera, Pentatomidae, Pentatominae), and description of a new species from India, ZooKeys 1148, pp. 79-117 : 79

Dunnius barpetensis Salini & Rabbani sp. nov.

Figs 36-41 , 42-48 , 49-52

Type locality.

India, Assam, Barpeta, Sorbhog, Ramie Research Centre, 26°31'25.3"N, 90°53'09.7"E.

Type material.

Holotype: ♂ (NIM), 'INDIA: Assam/ Barpeta, Sorbhog/ Ramie Research Centre/ 26°31'25.3"N, 90°53'09.7"E / 09.iii.2021, Rabbani, M. K.// HOLOTYPUS/ DUNNIUS BARPETENSIS sp. nov./det. Salini. S., 2022 [p, red label]'. Holotype is pinned, the dissected male genitalia placed in a plastic microvial with glycerol attached to the same pin, the detached right forewing glued on card. Paratype (1♀): India: Meghalaya/ Anggalanggri, South Garo hills/ 25°20'53.0"N, 90°13'37.8"E / 20.iii.2021, Rabbani, M. K.(NIM), dissected female genitalia placed in a glass microvial with glycerol attached to the same pin; abdominal tergites and ventrites glued on card; segment V of right antenna, whole tarsi including apical claws of right foreleg and left hind leg lost. The paratype bears the following identification label: 'PARATYPUS / DUNNIUS BARPETENSIS sp. nov. / det. Salini. S., 2022 [p, yellow label]'.

Description.

Colouration. Body above pale brown to ochraceous; head including antennae, 1/2 of anterolateral margins of pronotum and dorsum of scutellum pale white. Ocelli reddish. 1+1 small, round pale white spots located on posterior margin of pronotal calli. Membrane pale brown, translucent. Ventral side including legs creamy white except the following: apex of labiomere IV, apical 1/2 of tarsal claws, spiracular outline, minute spot at the antero- and postero-lateral angles of abdominal sternites III-VII, black.

Integument and vestiture. Body above covered with coarse, black punctures, densely concentrated towards anterior margin of pronotum and lateral margins of scutellum. Ventral side of body with black punctures mostly coarse and dense on thoracic sternites. Legs with minute black punctures sparsely distributed. The punctures finer on abdominal sternites, appear as four faint, indistinct streaks, gradually disappearing towards posterior 1/2. Ventral side of genital capsule with brown, sparse, fine punctures; terminalia with valvifers VIII, laterotergite VIII and laterotergite IX with fine, brown punctures.

Body glabrous, except the following: antennae and femora with fine, semi-erect, short setae; labium with sparse, golden setae; tibiae with dense, brown, short, semi erect setae on ventral side and dorsally with moderately elongate brown setae, dense mat of setae at the posterior end of tibiae; tarsomeres on dorsal side with moderately elongate golden setae and dense mat of short, golden setae on ventral side of all tarsomeres. Genital capsule (median region of ventral rim, posterolateral lobes and the infoldings of ventral rim with cushion-like region on either side of the median notch) with short, golden setae. Female genitalia (median region of valvifers VIII, valvifers IX laterally, laterotergite VIII and IX caudally) with short, brown semi-erect setae.

Structure. Head above flat, sloping downwards, much shorter than wide, lateral margins narrowly reflexed, slightly concave in front of compound eyes. Mandibular plates more than twice as wide as clypeus, but nearly as long as clypeus, not meeting in front of clypeus. Clypeus narrow throughout its length. Compound eyes moderately large, rounded, protruding out of the head outline in most of their width. Ocelli small, situated posteriorly near to posterior margin of head. Antenniferous tubercles short. Antennae with five antennomeres, slender, antennomeres from shortest to longest: I<IIb<IIa<IV<III; antennomere I approximately reaching apex of head, shortest and stoutest, antennomere IIa to cylindrical and slender and antennomere IV slightly thickened towards apex. Bucculae short, low, anterior apex angulate and sometimes developed into minute tooth. Labium passing mesocoxae, labiomere I as long as bucculae.

Pronotum. Anterior margin thin, with median concavity to accommodate posterior margin of head, shallow; anterolateral angles with tooth minute or indistinct laterally directed. Anterolateral margin obliquely straight, narrowly reflexed; posterolateral margin narrowly concave; posterior margin nearly straight, posterolateral angles rounded; humeri rounded. Disc of pronotum convex with anterior 2/3 sloping downwards.

Scutellum. Subtriangular, longer than broad at base; basal 1/2 of scutellar disc, gibbous; posterior 1/2, flat; abruptly narrowed at 1/3 from apex; caudal apex of scutellum narrowly rounded.

Hemelytra. Corium with anterodistal angles angulate, extending well beyond apex of scutellum. Membrane translucent with six or seven simple veins, without reticulate venation.

Thoracic pleuron and sternum. Pro- and meso-sternum with median longitudinal carina narrow throughout the length except slightly high at anterior apex, not extending beyond procoxae; posteriorly in contact with cruciform metasternal carina (Fig. 56 ); posterior apex of metasternal carina not hollowed out or grooved and not in contact with the apex of basal abdominal tubercle. External scent efferent system with peritreme well developed into spout-like, nearly reaching 1/3 of metapleural width.

Legs. Outer surface of tibiae sulcate. All tarsi with tarsomere II shortest, dorsally regularly rounded, tarsomeres I and III subequal.

Pregenital abdomen. Connexivum scarcely exposed. Posterolateral angles of abdominal ventrites with tooth minute or indistinct. Abdominal venter slightly convex medially, neither grooved nor keeled; ventrite III (= second visible abdominal segment) medially with tubercle short, apically rounded and stout.

Male genitalia (Figs 40 - 48 ). Genital capsule nearly quadrangular with posterolateral lobes (= caudal lobes) well developed and angular; apex of posterolateral lobes somewhat pointed. Dorsal rim widely excavated with narrow median emargination, sublaterally with convex lobe-like outgrowth nearly concealing the 1+1 triangular tooth-like structure (Fig. 41 ) on infoldings of dorsal rim. Dorsal sinus of posterior aperture semi-circular; infoldings of dorsal rim with 1+1 triangular, sclerotised, short, tooth-like projection on either side of the dorsal sinus. Ventral rim medially with shallow, roughly rectangular notch; infoldings of ventral rim well developed, either side of median notch developed into thick cushion-like triangulate (ct) region, possessing short, dense, semi-erect setae. Paramere with crown C-shaped in lateral view, short neck and small plate-like apodeme. Articulatory apparatus. Support bridge complex excavated cup-like, cone-like capitate processes attached with short dorsal connectives. Phallus. Phallotheca broader than long, dorsal region bulbous (Fig. 48 ) and ventral margin nearly straight (in lateral view); apical part of phallotheca broader than basal part, pair of short, stout, sclerotised, ventrolateral tubercles at the posterior end of phallotheca; conjunctival processes large, membranous subdivided into a pair of large, partly membranous, dorsal conjunctival processes (dcp), one median, short, membranous process (mcp) and pair of partly membranous, lateral conjunctival processes (lcp). Apex of dorsal conjunctival process smooth, curved into hook-like and that of lateral conjunctival processes rounded with minute serrations. Processes of aedeagus (pa) fused to form hollow structure, opening ventrally with broad oval aperture and enclosing short aedeagus; aedeagus tube-like with apex curved and phallotreme rounded.

Female genitalia. (Figs 39 , 49-52 ). Valvifers VIII transverse, broad and roughly quadrangular, with medial margins nearly straight; inner posterolateral angles angulate; posterior margin straight; valvifers IX single, nearly quadrangular sclerite; laterotergites IX oblique, elongate with inner margin broadly arcuate and outer margin more or less straight, caudal margin moderately sclerotised, caudal apex with short denticle; laterotergite VIII subquadrate, caudal margin slightly convex, with short sclerotised denticle on caudolaterally. A pair of ring sclerites (rs) elongate lanceolate. Spermatheca. Spermathecal dilation long, regularly and obliquely fluted; distal spermathecal duct narrow and shorter than proximal one; proximal spermathecal duct moderately broad and tubular; proximal flange shorter than distal flange; apical receptacle (ar) elongate, constricted at middle, large, bulbous base connected to short distal apical bulbous region by short, narrow region; apical bulbous region with two ductules, of which one elongate and other short, both facing towards distal rim and not reaching distal rim.

Measurements

(mm). Males (n = 1); Body length 12.77; head: length 1.84, width (including eyes) 3.01, interocular width 1.63; lengths of antennomeres: I - 0.50, II - 1.25, III - 1.05, IV - 1.67, V - 1.42; lengths of labiomeres: I- 0.89, II- 1.39, III- 0.83, IV- 0.74; pronotum: length 2.98, width (including humeri) 6.74; scutellum: length 4.63, width (at basal angles) 4.45.

Females (n = 1); Body length 14.12; head: length 1.92, width (including eyes) 3.24, interocular width 1.88; lengths of antennomeres: I - 0.57, II - 1.35, III - 1.16, IV - 1.62, V - 1.43; length of labiomeres: I - 1.02, II - 1.44, III - 1.14, IV - 0.71; pronotum: length 3.45, width (including humeri) 7.15; scutellum: length 5.17, width (at basal angles) 4.63.

Differential diagnosis.

This species resembles D. laticeps , D. tridentatus , and D. trifasciatus in external morphology and colouration and therefore difficult to differentiate unless the male genitalia has been examined. The characteristic shape of genital capsule (dorsal rim, ventral rim, 1+1 denticle-like structure on infoldings of dorsal rim), shapes of paramere and phallus can differentiate this species from its congeners.

Etymology.

The specific epithet, Dunnius barpetensis , is based on the name of the type locality; adjective.

Bionomics.

The species was collected on bamboo, Bambusa vulgaris Schrad. & J.C. Wendl.

Distribution.

This species is at present known only from Assam and Meghalaya.

Figures

Figures 36 - 41. Dunnius barpetensis Salini & Rabbani, sp. nov. 36 habitus (dorsal) 37 habitus (ventral) 38 external scent efferent system (arrow showing the peritreme) 39 close up of posterior end of ventral side of female abdomen (terminalia) 40 articulatory apparatus 41 genital capsule (dorsal) (arrow shows the triangular tooth-like structure). Scale bars: 1 mm (36, 37); 0.1 mm (38 - 41).

Figures 42 - 48. Dunnius barpetensis Salini & Rabbani, sp. nov. 42 genital capsule (ventral) 43 genital capsule (caudal) 44, 45 parameres (different planes) 46 phallus (ventral) 47 phallus (dorsal) 48 phallus lateral. Scale bar: 0.1 mm. Abbreviations: ct-cushion-like triangulate region; pa-processes of aedeagus; dcp-dorsal conjunctival processes; lcp-lateral conjunctival processes; mcp-median conjunctival processes.

Figures 49 - 52. Dunnius barpetensis Salini & Rabbani, sp. nov. 49 terminalia (dorsal) 50 terminalia (ventral) 51 spermatheca 52 spermathecal pump. Scale bars: 0.5 mm (49 - 51). Abbreviations: ar-apical receptacle; rs-ring sclerites.

Figures 56 - 62. Dunnius fulvescens (Dallas) 56 metasternal carina with cruciform posterior apex (arrow showing the cruciform posterior apex) and basal abdominal tubercle 57 external scent efferent system (arrow showing the peritreme) 58 close up of posterior end of ventral side of female abdomen (terminalia) 59 terminalia (dorsal) 60 terminalia (ventral) 61 spermatheca 62 spermathecal pump. Scale bar: 0.25 mm. Abbreviation: rs-ring sclerites.