Trisunius tenuincisus, 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 : 1536-1539

Trisunius tenuincisus nov.sp. ( Figs 13-18 , Map 1 )

T y p e m a t e r i a l: Holotype 3: " India: Meghalaya #9d, East Khasi Hills dist., Shillong Peak, 1900 m, 21.X.2004, 25°32'20''N, 91°51'03''E / Leg. G. Cuccodoro, C. Carlton, R. Leschen & D. Erne / Holotypus 3 Trisunius tenuincisus sp.n. det. V. Assing 2013" (MHNG). Paratype ♀: same data as holotype (cAss).

E t y m o l o g y: The specific epithet is an adjective composed of the Latin adjectives tenuis (narrow) and incisus (incised). It alludes to the conspicuously narrow posterior incision of the male sternite VIII.

D e s c r i p t i o n: Body length 3.2-3.5 mm; length of forebody 1.8-1.9 mm. Habitus as in Fig. 13 . Coloration: body reddish-brown to dark-brown; legs yellowish-red to brown; antennae reddish.

Head ( Fig. 14 ) approximately as long as broad (weakly oblong to weakly transverse); lateral margins behind eyes subparallel in dorsal view; punctation fine and dense; interstices with shallow microsculpture, narrower than diameter of punctures (except in median dorsal portion). Eyes of moderate size and weakly convex, nearly half as long as postocular region in dorsal view. Antenna approximately 1.0 mm long.

Pronotum ( Fig. 14 ) approximately 1.05 times as long as broad and approximately 0.9 times as broad as head; lateral margins converging posteriad in dorsal view; punctation dense and moderately fine, more distinct than that of head; midline narrowly impunctate; interstices without microsculpture.

Elytra ( Fig. 14 ) approximately as long as pronotum; punctation fine and dense; interstices without distinct microsculpture. Hind wings apparently fully developed. Metatarsomere I approximately as long as II.

Abdomen approximately as broad as elytra; punctation fine and very dense; posterior margin of tergite VII with palisade fringe.

3: sternite VII ( Fig. 15 ) transverse, with cluster of stout black setae in postero-median portion, posterior margin weakly convex in the middle; sternite VIII ( Fig. 16 ) distinctly transverse, posterior excision conspicuously narrow and deep; aedeagus ( Figs 17-18 ) 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: This species is readily distinguished from all its congeners by the chaetotaxy of the male sternite VII, the narrower posterior incision of the male sternite VIII, as well as by the shape of the aedeagus. For illustrations of the male sexual characters of other Trisunius species see ASSING (2011, 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 Meghalaya, northeastern India ( Map 1 ). The specimens were collected at an altitude of 1900 m. The long wings suggest that the species may be widespread.

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 13-18: Trisunius tenuincisus nov.sp.: (13) habitus; (14) forebody; (15) male sternite VII; (16) male sternite VIII; (17-18) aedeagus in lateral and in ventral view. Scale bars: 13: 1.0 mm; 14: 0.5 mm; 15-16: 0.2 mm; 17-18: 0.1 mm.