Leptusa armatissima, 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 : 268-272

Leptusa armatissima nov.sp. ( Figs 49-62 )

T y p e m a t e r i a l: Holotype 6: China: Yunnan [CH07-08], Dali Bai Auton. Pref., Diancang Shan 43 km NW Dali, 3078 m, 25°59'35"N, 99°52'06"E, W pass, Rhodod., oaks [sic], bamboo, sifted, 29. V.2007, M. Schülke / Holotypus 6 Leptusa armatissima sp.n. det. V. Assing 2007 (cAss) . Paratypes: 5 exs.: same data as holotype (cSch, cAss) ; 2 exs., same data, but leg. A. Pütz (cPüt, cAss) .

D e s c r i p t i o n: 2.1-2.7 mm. Habitus as in Fig. 49 . Coloration: head dark brown; pronotum and elytra reddish; abdomen blackish brown, with segments III-IV slightly paler brown and apex (posterior 1/4 of segment VII and following segments) reddish brown; legs and antennal bases reddish; antennae apically more or less infuscated, reddish brown to darker brown.

Head approximately 1.05 times as wide as long; puncturation sparse and extremely fine, barely noticeable; microsculpture distinct, but shallow. Eyes of moderate size, slightly longer than postocular region in dorsal view ( Fig. 50 ). Antennae moderately slender ( Fig. 51 ); antennomere IV approximately as long as wide; V indistinctly transverse; VI-X of increasing width and increasingly transverse; X slightly less than twice as wide as long. Maxillary palpus with penultimate palpomere approximately 2.5 times as long as wide.

Pronotum moderately convex in cross-section, strongly transverse, approximately 1.35 times as wide as long and 1.35 times as wide as head; maximal width in anterior half; posterior angles moderately marked; puncturation fine, slightly denser and more distinct than that of head; microsculpture distinct, more pronounced than that of head ( Fig. 50 ).

Elytra approximately 1.1 times as wide and at suture as long as pronotum, or slightly longer; humeral angles distinct; puncturation coarse and very dense, but not very deep; microsculpture very shallow, barely noticeable ( Fig. 50 ). Hind wings fully developed. Metatarsomere I of similar length as II.

Abdomen approximately 0.95 times as wide as elytra, widest at segments V/VI; tergites III-V with, tergites VI-VII without anterior impressions; puncturation of anterior impressions of tergites III-V rather coarse and dense, on remainder of tergites III-VI fine and moderately dense, on tergite VII sparse; microsculpture distinct everywhere; posterior margin of tergite VII with pronounced palisade fringe ( Fig. 52 ); tergites VII-VIII without evident sexual dimorphism ( Figs 53, 55 ).

6: sternite VII unmodified; posterior margin of sternite VIII obtusely pointed ( Fig. 54 ); median lobe of aedeagus stout, internal sac heavily armed with strongly sclerotised structures ( Figs 60-62 ); paramere as in Figs 57-58 .

♀: posterior margin of sternite VIII strongly convex ( Fig. 56 ); spermathecal capsule with long and slender cuticular intrusion ( Fig. 59 ).

E t y m o l o g y: The name (Latin, adjective, superlative of armata) refers to the numerous and large sclerotised structures in the internal sac of the aedeagus.

C o m p a r a t i v e n o t e s a n d s u b g e n e r i c a f f i l i a t i o n s: From all other Leptusa species known from the Eastern Palaearctic region, L. armatissima is readily separated by the distinctive morphology of the aedeagus, as well as by the shape of the spermatheca. Since neither the sexual nor the external characters suggest closer a relationship to any of the described subgenera present in the Eastern Palaearctic region, a subgeneric assignment is here refrained from. The external shape of the aedeagus somewhat resembles that of species of Aphaireleptusa, but the internal structures, the shape of the paramere, the male secondary sexual characters (especially sternite VII), and the external morphology (body shape, puncturation, etc.) are completely different.

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 some 40 km to the northwest of Dali, northwestern Yunnan province, China. The type specimens were sifted from the litter of Rhododendron, oak, and bamboo at an altitude of about 3080 m.

Figures

Figs 49-59: Leptusa armatissima nov.sp.: (49) habitus; (50) forebody; (51) antenna; (52) abdominal segments III-VII; (53) male tergite VIII; (54) male sternite VIII; (55) female tergite VIII; (56) female sternite VIII; (57) apical lobe of paramere; (58) paramere; (59) spermatheca. Scale bars: 49- 50, 52: 0.5 mm; 51, 53-56, 58: 0.2 mm; 57, 59: 0.1 mm.

Figs 60-62: Leptusa armatissima nov.sp.: median lobe of aedeagus is lateral and in ventral view. Scale bar: 0.1 mm.