Neosclerus praeacutus, Assing, 2011

Assing, Volker, 2011, A revision of the genus Neosclerus C (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 6 (1), pp. 89-148 : 105-106

Neosclerus praeacutus sp. n. ( Figs 34-39)

Type material:

Holotype : " China (N-Yunnan), Lijiang Naxi Aut. Co., 3 km NW Yongsheng, 53 km WSW Lijiang, 1950-2000 m, 26°41.8'N, 100°43.1'E (SE-slope, secondary broadleaved forest) 14.VIII.2003, Wrase [03] / Holotypus  Neosclerus praeacutuspraeacutus sp. n. det. V. Assing 2010 " (cAss) . Paratypes: 3 exs.: " China: N-Yunnan [C03-03], Lijiang Naxi Aut. Co., 3 km NW Yongsheng, 53 km WSW Lijiang, 26°41'.8'N, 100°43.1'E, 1950-2000 m, SE slope, secondary broadleaved forest, 14.VIII.2003, leg. M. Schülke " (cSch, cAss); 10 exs.: " China: Yunnan [CH07-31], Dali Bai Auton. Pref., mtn. range N Er Hai, 42 km N Dali, 26°04'53''N, 100°09'39''E, 2500-2550 m, NE slope with oaks, litter sifted, 12.VI.2007, M. Schülke " (cSch, cAss); 1 : " China: N-Yunnan, Dali Bai Nat. Aut. Pref., 1 km W Dali, foothill of Diancang Shan, 25°41.9'N, 100°08.4'E, 2170 m, 3.IX.2003, A. Smetana [C146]" (cSme); 1 : " China (Yunnan), Nujiang Lisu Aut. Pref., Salween side valley 5 km S Fugong, road SS 228 km 223 (creek bank, litter sifted), 8.VI.2007, D.W. Wrase [25]" (cSch); 3 , " China: Yunnan, (CH07-25), Nujiang Lisu Aut. Pref., Salween side valley 5 km S Fugong, road SS 228 km 223, under stones, moist embankment, 8.VI.2007, leg. A. Pütz " (cPüt, cAss); 1 : " China: Yunnan, Lijiang , Qiaotou, 14.IV.2003, stream moss and litter, G. de Rougemont leg." (cRou); 1 : " China: N-Yunnan, Diqing Tibet Aut. Pr., Deqin Co. , gully W Jinsha Jiang river, 33 km WNW Zhongdian, 27°56.75'N, 99°24.42'E, 2300 m, 4.VI.2005, A. Smetana [C151]" (cAss) .

Description:

Body length 3.0- 3.7 mm. Habitus as in Fig. 34. Coloration: body blackish, pronotum and elytra sometimes indistinctly paler; legs and antennae yellowish.

Head across eyes approximately 1.2 times as wide as long; postocular region very short, shorter than width of antennomere IV; punctation moderately coarse and moderately dense, sparser in posterior portion of dorsal surface ( Fig. 35); interstices in anterior and median dorsal portion without microsculpture and glossy, in posterior portion often with shallow traces of microreticulation; antenna approximately 0.9 mm long.

Pronotum approximately as long as wide or indistinctly oblong, and 0.80-0.85 times as wide as head; punctation similar to that of head ( Fig. 35); impunctate midline of variable width, often narrow or ill-defined (particularly in anterior half); interstices without microsculpture and glossy.

Elytra short, approximately 0.85 times as long, and 1.05-1.15 times as wide as pronotum, slightly widened posteriad; humeral angles relatively weakly marked ( Fig. 35); punctation fine, dense, shallow, and relatively ill-defined. Hind wings present, but probably of reduced length.

Abdomen approximately as wide as elytra; punctation fine, moderately dense, somewhat sparser on tergite VII than on anterior tergites; interstices with shallow microsculpture; posterior margin of tergite VII with palisade fringe.

: sternite VII with posterior margin weakly and broadly convex in the middle, in posterior median portion with cluster of slightly modified (stouter and darker) setae ( Fig. 36); sternite VIII anteriorly unmodified, with sparse pubescence, in posterior median portion without pubescence, posterior excision V-shaped, its depth approximately 1/6 the length of sternite ( Fig. 37); aedeagus with long, straight, subapically weakly dentate, and apically very acute ventral process; internal sac with pair of elongate sclerotized structures ( Figs 38-39).

Etymology:

The name (Latin, adjective: pointed, sharpened) refers to the apically acute ventral process of the aedeagus.

Comparative notes:

This species is best distinguished from its congeners by the morphology of the aedeagus, particularly the shape of the ventral process. It is separated from the similar N .. glaber , which is apparently widespread in southern China, by the shorter and more slender elytra, as well as by the shape and chaetotaxy of the male sternites VII and VIII.

Distribution and bionomics:

The known distribution is confined to four localities in Yunnan, China, where the type specimens were sifted from leaf litter and moss in forests and on stream banks at altitudes of 1950 -

2550 m in April, June, and August.