Trisunius borailicus, Assing, 2013

Assing, V., 2013, A revision of Trisunius III. Three new species from North India and Nepal, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (2), pp. 1531-1540 : 1535

Trisunius borailicus nov.sp. ( Figs 7-12 , Map 1 )

T y p e m a t e r i a l: Holotype 3: " India: Assam, North #8a, Cachar Hills dist., Mt Borail, Borail Peak, 1700 m, 19.x.2005, 25°06'43''N, 93°03'11''E / sifting bamboo #8a, leaf litter in mountain rain forest, Cuccudoro & Marletta / Holotypus 3 Trisunius borailicus sp.n. det. V. Assing 2013" (MHNG). Paratypes: 3♀♀: same data as holotype (MHNG, cAss).

E t y m o l o g y: The specific epithet is an adjective derived from the name of the mountain where the species was discovered.

D e s c r i p t i o n: Body length 2.7-3.2 mm; length of forebody 1.5-1.6 mm. Habitus as in Fig. 7 . Coloration: head and abdomen brown; pronotum and elytra dark-reddish to reddish-brown; legs yellowish-red; antennae reddish.

Head ( Fig. 8 ) approximately as long as broad; lateral margins behind eyes subparallel or convex in dorsal view; punctation fine and moderately sparse; interstices with very shallow microsculpture, broader than diameter of punctures. Eyes small, approximately one third as long as postocular region in dorsal view. Antenna 0.8-0.9 mm long.

Pronotum ( Fig. 8 ) 1.05-1.10 times as long as broad and 0.90-0.95 times as broad as head; lateral margins converging posteriad in dorsal view; punctation rather dense and fine, but more distinct than that of head; midline narrowly impunctate; interstices without distinct microsculpture.

Elytra ( Fig. 8 ) short, approximately 0.75 times as long as pronotum; punctation fine and dense; interstices without distinct microsculpture. Hind wings completely reduced. Metatarsomere I approximately as long as II.

Abdomen distinctly broader than elytra; punctation fine and very dense; posterior margin of tergite VII without palisade fringe.

3: sternite VII ( Fig. 9 ) moderately transverse, pubescence weakly modified, posterior margin weakly concave in the middle, with transverse row of long dark submarginal setae; sternite VIII ( Fig. 10 ) weakly transverse, posterior excision narrowly V-shaped and moderately deep; aedeagus ( Figs 11-12 ) small, 0.33 mm long; ventral process laterally compressed.

C o m p a r a t i v e n o t e s: In external (size, short wings, etc.) and the male sexual characters, T. borailicus somewhat resembles T. manasluensis ASSING 2012 from the Manaslu range in Nepal, but differs by the more distinctly concave posterior margin of the male sternite VII, the distinctly narrower posterior excision of the less transverse male sternite VIII, as well as by the completely different shape of the ventral process of the aedeagus. For illustrations of T. manasluensis see ASSING (2012).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Thetypelocalityissituatedin Assam province, northeastern India ( Map 1 ). The specimens were sifted from bamboo litter in a mountain rain forest at an altitude of 1700 m.

Figures

Map 1: Distribution of the genus Trisunius in the Himalaya and in North India. Trisunius monticola (filled and open triangles); T. volans (open triangle); T. manasluensis and T. opaciceps (filled circle); T. perpusillus (open diamond); T. alesi (star); T. tenuincisus (open circle); T. borailicus (filled diamond).

Figs 7-12: Trisunius borailicus nov.sp.: (7) habitus; (8) forebody; (9) male sternite VII; (10) male sternite VIII; (11-12) aedeagus in lateral and in ventral view. Scale bars: 7: 1.0 mm; 8: 0.5 mm; 9- 10: 0.2 mm; 11-12: 0.1 mm.