Dunnius fulvescens (Dallas, 1851)

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 fulvescens (Dallas, 1851)

Figs 53-55 , 56-62

Rhaphigaster (Raphigaster) fulvescens Dallas, 1851: 283 (original description). Holotype: ♀ (NHM:? lost, M Webb, pers. comm.).

Rhaphigaster fulvescens : Dohrn (1859): 18 (checklist); Walker (1867): 373 (list); Stål (1876): 129 (incertae sedis); Lethierry and Severin (1893): 200 (catalogue).

Plexippus fulvescens : Distant (1900b): 387 (distribution); Distant (1901): 102 (distribution).

Dunnius fulvescens : Distant (1902): 232, fig. 145 (redescription; figures of habitat in dorsal view, mesothorax, metathorax and abdomen in ventral view; distribution); Kirkaldy (1909): 137 (catalogue); Chatterjee (1934): 22 (distribution, record from Assam and Naga hills, host); Chandra (1953): 92 (record from Tamil Nadu); Mathur and Singh (1960): 20 (host); Yang (1962): 117, 124-125 (distribution, key to tribe Antestiarini ); Jiang (1985): 67 (distribution in China); Zhang et al. (1987): 144 (key); Zhang and Lin (1990): 3 (distribution in China); Yang (1993): 213 (distribution in China); Zhang et al.(1995): 58, pl. 14, fig. 143 (description); Rider et al. (2002): 139 (Chinese distribution, checklist); Chakraborty and Ghosh (2003): 517 (checklist for Sikkim); Rider (2006): 317 (catalogue).

Type locality.

Country unknown (Dallas, 1851).

Type material.

Not examined, only image of type was seen. The original description was based on female specimen (or specimens?). The type is supposedly deposited in NHM, London; however, it appears to be lost at present (M Webb, pers. comm.). The image of the type (Fig. 53 ) was captured prior to its loss, provided by P Kment.

Material examined.

India: Arunachal Pradesh: 1♀, Pasighat, 2-11 May 2014, Veena Kumari, K., ICAR-NBAIR (NIM) .

Redescription.

Colouration Body above pale brown to ochraceous. Ocelli reddish. 1+1 small, round, yellow spots on anterior 1/2 of pronotum, located on posterior margin of pronotal calli. Small, pale yellow irregular markings scattered on the pronotal disc. Membrane translucent with brown veins. Antennae and legs paler than dorsal colouration. Ventral side concolourous to dorsal except the following: four narrow broken longitudinal stripes (two laterally and another two sublaterally, formed from coarse, black punctures), spiracular outline, posterolateral angles of abdominal sternites III-VII, moderately large and round spot on mesosternum, apex of labiomere IV, black.

Integument and vestiture. Body above (Fig. 54 ) covered with coarse, black punctures, dense on head (dorsally), pronotum and scutellum; clusters of punctures sometimes forming irregular markings especially on head and pronotum; punctures on hemelytra are less dense; head (ventrally), thoracic pleura and abdominal sternites (four broken longitudinal stripes) with coarse, brown punctures; connexivum with fine, brown punctures.

Body glabrous except antennae and legs moderately pilose. Terminalia of female genitalia with valvifers VIII and IX, laterotergites VIII and IX provided with sparse, coarse, brown punctures.

Structure. See the generic redescription.

Male genitalia. Unknown.

Female genitalia (Figs 58-62 ). Valvifers VIII transverse, broad and quadrangular, with medial margins straight; inner posterolateral angles angulate; posterior margin nearly straight; valvifers IX single, transverse, large subtrapezoidal sclerite with caudal margin concave; laterotergites IX oblique, elongate; outer margins and caudal 1/2 of inner margin straight; caudal margin of laterotergites IX irregularly truncated; laterotergites VIII subquadrangular with outer margins more or less obliquely straight; caudo-lateral margin with indistinct, denticle, black. A pair of ring sclerites (rs) (Fig. 60 ) elongate, roughly oblong. Spermatheca (Fig. 61 ). Spermathecal dilation long, regularly, fluted; distal spermathecal duct narrow, shorter than proximal one; proximal spermathecal duct thick, elongate and tubular, sclerotised rod at the middle of lumen of spermathecal dilation twisted at proximal end beyond the dilation; proximal flange nearly 1/2 of distal flange; apical receptacle drop-shaped constricted towards apex, bearing three ductules apically, facing towards distal rim and not reaching distal rim.

Measurements

(mm). Females (n = 1); Body length 11.16; head: length 1.57, width (including eyes) 2.72, interocular width 1.53; lengths of antennal segments: I -0.43, II - 1.25, III - 1.03, IV - 1.46, V- 1.31; length of labial segments: I -0.60, II - 1.25, III - 0.87, IV - 0.64; pronotum: length 2.66, width (including humeri) 6.47; scutellum: length 4.77, width (at basal angles) 4.04.

Differential diagnosis.

This species resembles other members of this genus externally but the genitalia characters like the laterotergites IX having the caudal margin irregularly truncated, smooth, without any denticle and the drop-shaped apical receptacle differentiates this species from its congeners.

Distribution.

India: Sikkim (Mungphu), Tamil Nadu (Udhagamandalam = Ootacamund) (Distant, 1900b), Arunachal Pradesh (Pasighat) (new record); Burma (Distant, 1902); China (Rider, unpublished catalogue).

Figures

Figures 53 - 55. Dunnius fulvescens (Dallas) 53 syntype image (dorsal habitus), courtesy: P. Kment 54 habitus (dorsal) 55 habitus (ventral). Scale bars: 1 mm.

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.