Trisunius spathulatus, Assing, 2011

Assing, V., 2011, Trisunius gen. nov. from the southern East Palaearctic and the Oriental regions (Coleoptera: Staphylinidae: Paederinae: Medonina), Linzer biologische Beiträge 43 (1), pp. 195-220 : 198-200

Trisunius spathulatus nov.sp. ( Figs 1-9 )

T y p e m a t e r i a l: Holotype Ƌ: " China: Yunnan, Lincang Pref., Bangma Shan , 33 km SSW Lincang, 2150 m, 23°35'41''N, 100°00'27''E, decid. forest remnant, N-slope, litter and dead wood sifted, 11.IX.2009, leg. M. Schülke [CH09-42] / Holotypus Ƌ Trisunius spathulatus sp. n. det. V. Assing 2011" (cAss) . Paratypes: 131 exs. [13 teneral]: same data as holotype ( OÖLL, cSch, cAss) ; 7 exs.: " China: Yunnan, Lincang Pref., Bangma Shan, 20 km NW Lincang, 2210 m, 23°58'25''N, 99°54'36''E, water reservoir, devast. forest with ferns, litter & ferns sifted, reservoir bank, 9.IX.2009, leg. M. Schülke [CH09-37]" (cSch, cAss); 1♀: " China: Yunnan, Lincang Pref., Mekong valley , small creek cleft, 38 km SSE Lincang, 854 m, 23°33'13.2''N, 100°09'56.8''E, wet litter & flood debris under waterfall, 11.IX.2009, leg. M. Schülke " [CH09-44a]" (cSch); 2 exs.: " China: Yunnan, Lincang Pref., Laobie Shan, Wei Bo Shan pass, 24°08'16''N, 99°42'53''E, 2375 m, creek valley, devastated second. decid. forest, litter & moss sifted, 8.IX.2009, leg. M. Schülke [CH09-35]" (cSch); 2 exs.: " China: Yunnan, Pu'er Pref., Ailao Shan, 37 km NW Jingdong, 24°45'12''N, 100°41'24.5''E, 2300 m, devastated forest remnant, litter & dead wood sifted, 13.IX.2009, leg. M. Schülke [CH09-48]" (cSch, cAss); 6 exs.: " China (Yunnan) Pu'er Pref., Ailao Shan, 37 km NW Jingdong, 24°45'12''N, 100°41'24.5''E, 2300 m (devastated forest remnant, litter, moss, grass roots sifted, 13.IX.2009, D.W. Wrase [48]" (cSch, cAss); 3 exs.: " China: Yunnan, Dali Bai Aut. Pref., Wuliang Shan, 9 km SW Weishan, 25°10'15.5''N, 100°14'21.8''E, 2480 m (scrub with oak, alder, pine), litter & mushrooms sifted, 14.IX.2009, leg. M. Schülke [CH09-51]" (cSch, cAss); 7 exs. [2 teneral]: " China: Yunnan, Dali Bai Aut. Pref., Wuliang Shan, 11 km SW Weishan, 24°08'46.7''N, 100°14'14.1''E, 2520 m, pine forest, litter & dead wood sifted, 14.IX.2009, leg. M. Schülke [CH09-52]" (cSch, cAss); 5 exs.: " China: Yunnan, Lincang / Dali Pref., Wuliang Shan, old pass road, N pass, 24°45'16.4''N, 100°29'50.3''E, 2350 m, forest remnant & tea plantation litter, mushrooms, grass sifted, 16.IX.2009, leg. M. Schülke [CH09-55]" (cSch, cAss).

D e s c r i p t i o n: Body length 3.0- 3.5 mm. Habitus as in Fig. 1 . Coloration: head dark-brown to blackish-brown; pronotum and elytra reddish to reddish-brown; abdomen reddish to dark-brown, with the apex reddish; legs and antennae reddish.

Head ( Fig. 2 ) weakly oblong, approximately 1.05 times as long as wide; punctation fine and moderately dense; interstices with fine, but distinct microsculpture ( Fig. 3 ). Eyes approximately half as long as postocular region in dorsal view. Antenna as in Fig. 4 . Anterior margin of labrum with two distinct teeth on either side of median incision. Labial palpi as in Fig. 5 .

Pronotum ( Fig. 2 ) approximately 1.1 times as long as wide and 0.90-0.95 times as wide as head; punctation rather fine and dense, more distinct than that of head; midline with narrow impunctate band not reaching anterior and posterior margins; interstices without microsculpture.

Elytra short, usually 0.85-0.95 times as long as pronotum; humeral angles marked ( Fig. 2 ); punctation dense and shallow, less defined than that of pronotum; interstices without microsculpture. Hind wings of reduced length, approximately twice as long as elytra

(approximately 30 specimens examined). Metatarsomere I approximately as long as II.

Abdomen slightly broader than elytra, widest at segment VI; punctation fine and dense; interstices with distinct microsculpture; posterior margin of tergite VII with palisade fringe.

Ƌ: sternite VII with shallow impression in posterior median portion, on either side of this impression with extensive cluster of long dark setae ( Fig. 6 ); sternite VIII with median impression and with deep and rather narrow V-shaped excision ( Fig. 7 ); aedeagus approximately 0.45 mm long, with long and slender ventral process ( Fig. 8 ); apex of ventral process scoop-shaped in ventral view ( Fig. 9 ).

E t y m o l o g y: The specific epithet is an adjective derived from the Latin noun spathula (scoop, spattle) and refers to the conspicuous shape of the ventral process of the aedeagus.

C o m p a r a t i v e n o t e s: This species is characterized particularly by the chaetotaxy of the male sternite VII and by the shape of the aedeagus. It is distinguished from many of its congeners also by the relatively short elytra and by the reduced length of the hind wings.

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: Trisunuius spathulatus is known from several localities in southwestern Yunnan, where it was sifted from forest litter at altitudes of 2150-2520 m in September; one specimen was sifted from wet debris at a waterfall at approximately 850 m. Syntopic species are T. cultellatus , T. schuelkei , T. iaculatus , and T. truncatus . Several specimens are teneral.

Figures

Figs 1-9: Trisunius spathulatus nov.sp.: (1) habitus; (2) forebody; (3) median dorsal portion of head; (4) antenna; (5) labial palpi; (6) male sternite VII; (7) male sternite VIII; (8-9) aedeagus in lateral and in ventral view. Scale bars: 1: 1.0 mm; 2: 0.5 mm; 4, 6-7: 0.2 mm; 3, 5, 8-9: 0.1 mm.