Polistes brunus Nguyen and Carpenter, 2017

Polistes brunus Nguyen and Carpenter, 2017, Raffles Bulletin of Zoology 65: 271–273, 278, figs. 7–12, female, nest (in Polistes stigma group)—“ VIETNAM, Dak Lak, Ea Kar, 95 m ” (IEBR).

Polistes brunus was described by Nguyen and Carpenter, 2017 based on a female specimen (holotype) from Ea Kar, Dak Lak [Vietnam], which is housed in the Institute of Ecology and Biological Resources, and the nest of the species was also described at that time. The male of this species is described here for the first time; it is similar to the female both in structure and coloration except for some characters mentioned below.

Material examined. 1 male, Ham Thuan Nam, Binh Thuan, 10°51′N 109°53′E, Nest#: VNM-Oili- 2005- 05, 11.viii.2005, Nguyen LTP & Kojima J; Dang HT 1 male (IEBR), An Hai, Ly Son, Quang Ngai, 15°22′42″N 109°07′47″E, alt. 1830m, 6.viii.2017, Dang HT .

Description. Male [female characters in square brackets]. Body length 12 mm [10.1–13.7 mm]; fore wing length 11.8 mm [9.2–13.4 mm].

Head in frontal view (Fig. 15) about 1.2 × [about 1.1 ×] as wide as high. Vertex slightly raised in area among ocelli; POD:OOD=1:1.2 [1:1.5]; POD about 2.0 × [about 2.1 ×] Od. Inner eye margins about 1.2 × [about 1.1 ×] further apart from each other at vertex than at clypeus. Gena narrow [more or less wide], in lateral view about 0.4 × [about 0.8 ×] as wide as eye. Clypeus in frontal view (Fig. 16) slightly higher than wide [as wide as high], apical margin slightly produced, broadly rounded [pointed apically]; surface covered with dense short golden setae [clypeus with scattered large punctures, each bearing sharply pointed golden bristle; tomentum on clypeus covering approximately dorsal half of clypeus]. Antenna (Fig. 17) with slenderer flagellum than in female; scape long, about 3.2 × [about 2.8 ×] as long as its maximum width; F1 3.1 × [2.8 ×] as long as apical width; terminal flagellomere not curved [bullet shaped], about 1.7 × longer than [1.2 × as long as] its basal width. S7 without tubercle.

Body surface sculpture as in female, except for unpunctured clypeus.

Color. Similar to female but T4 without apical yellow band [with apical yellow band].

Male genitalia. Similar to those of other Polistes stigma group species. Digitus in inner aspect of paramere (Fig. 18) about 3.2 times as long as wide (measured at widest part), distinctly swollen near base, gradually narrowed apically to near apex, then slightly swollen towards the rounded apex. Aedeagus (Figs. 19, 20): penis valves about 0.6 times as long as basal apodeme, in ventral view narrowest near mid-length, weakly swollen proximally from mid-length then distinctly produced laterally near proximal margin, in lateral view slightly thickened in proximal one fourth and with dorsal margin weakly sinuate, with proximoventral corner produced into obtuse angle (Fig. 20); ventral margins of penis valves finely serrate along entire length.