Trisunius volans, 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 : 1532-1535

Trisunius volans nov.sp. ( Figs 1-6 , Map 1 )

T y p e m a t e r i a l: Holotype 3: "Jubing, 1300 m, 20.VI.1979 / O. Nepal, Bhakta B. / Holotypus 3 Trisunius volans sp. n. det. V. Assing 2013" ( NHMB).

E t y m o l o g y: The specific epithet is the present participle of the Latin verb volare (to fly) and refers to the long elytra, the external character best distinguishing this species from other Himalayan species of the genus.

D e s c r i p t i o n: Body length 3.1 mm; length of forebody 1.7 mm. Habitus as in Fig. 1 . Coloration: forebody reddish-brown, elytra with paler posterior margins; abdomen brown with paler apex; legs and antennae reddish-yellow.

Head ( Fig. 2 ) weakly oblong, 1.03 times as long as broad; lateral margins behind eyes subparallel in dorsal view; punctation fine and dense; interstices without distinct microsculpture. Eyes relatively large, slightly more than half as long as postocular region in dorsal view. Antenna 0.8 mm long.

Pronotum ( Fig. 2 ) 1.05 times as long as broad and 0.95 times as broad as head; lateral margins very weakly converging posteriad in dorsal view; punctation fine and rather dense, but somewhat less dense than that of head; interstices without distinct microsculpture.

Elytra ( Fig. 2 ) rather long, approximately 1.15 times as long as pronotum; punctation fine and dense; interstices without distinct microsculpture. Hind wings fully developed. Metatarsomere I approximately as long as II.

Abdomen narrower than elytra; punctation fine and very dense; posterior margin of tergite VII with palisade fringe.

3: sternite VII ( Fig. 3 ) moderately transverse, pubescence not distinctly modified, posterior margin truncate; sternite VIII ( Fig. 4 ) approximately as long as broad, posterior excision rather small and V-shaped; aedeagus ( Figs 5-6 ) small, 0.3 mm long; ventral process laterally compressed.

C o m p a r a t i v e n o t e s: The new species differs from the externally similar and sympatric T. monticola particularly by the longer and relatively broader elytra, the much smaller posterior excision of the male sternite VIII, as well as by the completely different morphology of the aedeagus. For illustrations of T. monticola see ASSING (2011).

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 eastern Nepal ( Map 1 ) at an altitude of 1300 m. The holotype was collected together with a female of T. monticola .

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 1-6: Trisunius volans nov.sp.: (1) habitus; (2) forebody; (3) male sternite VII; (4) male sternite VIII; (5-6) aedeagus in lateral and in ventral view. Scale bars: 1: 1.0 mm; 2: 0.5 mm; 3-4: 0.2 mm; 5-6: 0.1 mm.