Leptusa (Drepanoleptusa) stimulans, Assing, 2008

Assing, V., 2008, Seven new species and additional records of Palaearctic Leptusa, primarily from Yunnan, China (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 40 (1), pp. 251-273 : 254-255

Leptusa (Drepanoleptusa) stimulans nov.sp. ( Figs 1-10 )

T y p e m a t e r i a l: Holotype 6: China: Yunnan [ CH 07-28A], Nujiang Lisu Aut. Pref., Gaoligong Shan, side valley 19 km NW Liuku, 25°59'02"N, 98°42'23"E, 2730 m, devast. prim. for., litter sifted, 10.VI.2007, M. Schülke / Holotypus 6 Leptusa stimulans sp.n. det. V. Assing 2007 (cAss).

D e s c r i p t i o n: 3.9 mm. Habitus as in Fig. 1 . Coloration: head blackish; pronotum castaneous with rufous margins; elytra and abdomen reddish to reddish brown, with abdominal segment VI and anterior half of VII infuscated; legs and antennae reddish.

Head approximately 1.05 times as wide as long; puncturation rather coarse and dense, interstices narrower than diameter of punctures; microsculpture very shallow, barely noticeable. Eyes slightly longer than postocular region in dorsal view ( Fig. 2 ). Antennae ( Fig. 3 ) slender; antennomere X weakly transverse, distinctly less than 1.5 times as wide as long. Maxillary palpi slender, preapical palpomeres more than 3 times as long as wide.

Pronotum 1.28 times as wide as long and 1.28 times as wide as head; maximal width in anterior half; posterior angles marked; puncturation sparser and distinctly finer than that of head; microsculpture more pronounced than that of head ( Fig. 2 ).

Elytra 1.25 times as wide and at suture almost 1.20 times as long as pronotum; humeral angles pronounced; puncturation coarse (much more so than that of pronotum) and somewhat granulose, but not very dense, interstices wider than diameter of punctures ( Fig. 2 ); microsculpture absent. Hind wings apparently fully developed. Legs slender; metatarsomere I longer than II, but shorter than the combined length of II and III.

Abdomen approximately 0.9 times as wide as elytra, segments III-VI subparallel; segments III-VI with pronounced anterior impressions; puncturation rather coarse, dense on tergite III, decreasing in density from tergite III to tergite VI; tergite VII with rather sparse, oblongly granulose puncturation; microreticulation distinct, rather shallow on anterior tergites and pronounced on tergite VII; posterior margin of tergite VII with pronounced palisade fringe ( Fig. 4 ).

6: tergite VII with pronounced median keel ( Fig. 4 ); posterior margin of tergite VIII concave and distinctly serrate ( Fig. 5 ); sternite VII unmodified; sternite VIII broadly convex posteriorly ( Fig. 6 ); median lobe of aedeagus slender, ventral process acute both in lateral and in ventral view ( Figs 7-8 ); paramere as in Figs 9-10 .

♀: unknown.

E t y m o l o g y: The name - present participle of stimulare (to sting) - refers to the apically acute ventral process of the aedeagus.

C o m p a r a t i v e n o t e s: Leptusa stimulans is distinguished from all its congeners especially by the distinctive morphology of the median lobe of the aedeagus. Based on the shape of the aedeagus (median lobe, apical lobe of paramere), the male secondary sexual characters, and external characters, the species is attributed to Drepanoleptusa PACE . The only representative of this subgenus previously known from Yunnan is L. discolor . From this species, L. stimulans is additionally separated by distinctly larger body, darker coloration ( L. discolor : head brown, pronotum and elytra bright reddish), much longer antennae with less transverse antennomeres IV-X ( L. discolor :

antennomeres VII-X approximately twice as wide as long), larger eyes, and a much finer puncturation of the pronotum. For illustrations of L. discolor and of other Drepanoleptusa species known from mainland China (L. sichuanensis PACE, L. rougemonti PACE, L. microvolans PACE, L. erlangensis PACE, L. chengduensis PACE, L. wuyica ASSING, L. titillans ASSING) see PACE (1997, 1999, 2001) and ASSING (2002, 2006).

D i s t r i b u t i o n a n d b i o n o m i c s: The type locality is situated to the northwest of Liuku, western Yunnan province, China. The holotype was sifted from the leaf litter of a degraded primary forest at an altitude of 2730 m.

Figures

Figs 1-10: Leptusa stimulans nov.sp.: (1) habitus; (2) forebody; (3) antenna; (4) abdominal segments III-VII; (5) male tergite VIII; (6) male sternite VIII; (7-8) median lobe of aedeagus in lateral and in ventral view; (9) paramere; (10) apical lobe of paramere. Scale bars: 1: 1.0 mm; 2-4: 0.5 mm; 5-9: 0.2 mm; 10: 0.1 mm.