Tetrabothrus brevalatus, Assing, 2015

Assing, Volker, 2015, On the Tetrabothrus fauna of China (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Linzer biologische Beiträge 47 (1), pp. 127-143 : 136-138

Tetrabothrus brevalatus nov.sp. ( Figs 18-23 , Map 1 )

T y p e m a t e r i a l: Holotype Ƌ: " CHINA: Yunnan, Lincang Pref., Xue Shan, 11 km ENE Lincang, 2510 m, 23°55'01''N, 100°11'17.5''E, second. pine forest with Rhodod., small cleft with water, litter & mushrooms sifted, 10.IX.2009, leg. M. Schülke [ CH 09-39] / Holotypus Ƌ Tetrabothrus brevalatus sp. n., det. V. Assing 2015" (cAss). Paratype ♀: same data as holotype (cSch).

E t y m o l o g y: The specific epithet is an adjective composed of the Latin adjectives brevis (short) and alatus (winged). It alludes to the conspicuously short elytra.

D e s c r i p t i o n: Body length 6.3-7.0 mm; length of forebody 2.6-2.8 mm. Coloration: forebody body dark-brown to blackish-brown; abdomen blackish, with the apex (segments VIII-X) and the posterior margins of segments III-VII reddish-brown; legs reddish-brown, with the femoral bases slightly paler; antennae blackish-brown.

Head ( Fig. 18 ) approximately 1.2 times as broad as long; posterior angles obsolete; punctation extremely fine and sparse; median dorsal portion impunctate; pubescence whitish and suberect; microsculpture absent. Eyes large and bulging, but noticeably shorter than distance from posterior margin of eye to posterior constriction in dorsal view. Antenna relatively long and massive, 1.7 mm long, shaped as in Fig. 19 .

Pronotum ( Fig. 18 ) transverse, 1.10-1.12 times as broad as long and 1.12-1.18 times as broad as head, broadest in the middle, narrowly margined; lateral margins weakly convex in dorsal view; posterior angles rounded, but noticeable; anterior angles both visible in dorsal view; punctation sparse and very fine; midline broadly impunctate; pubescence withish and suberect; microsculpture absent.

Elytra ( Fig. 18 ) conspicuously short, approximately 0.55 times as long as pronotum; punctation sparse and fine; pubescence yellowish, conspicuously long, and suberect; interstices without microsculpture. Hind wings reduced. Legs long; metatibia 1.24-1.28 mm long; metatarsus 0.63-0.68 times as long as metatibia; metatarsomere I approximately as long as the combined length of II and III.

Abdomen ( Fig. 20 ) broader than elytra, broadest at tergite V; tergites III-VI with moderately deep anterior impressions, the impression of tergite VI as deep as that of tergite V; tergites III-VI without microsculpture and impunctate except for few punctures bearing long dark setae at the posterior margins; tergite VII posteriorly with several long blackish setae, with or without narrow rudiment of a palisade fringe; tergite VIII posteriorly with thin and moderately long yellowish setae, posterior margin weakly convex or truncate.

Ƌ: sternite VIII transverse, posterior margin obtusely pointed in the middle; median lobe of aedeagus 0.6 mm long and shaped as in Figs 21-22 ; paramere ( Fig. 23 ) 0.8 mm long and with long and slender apical lobe.

♀: posterior margin of sternite VIII strongly convex, in the middle truncate and with short marginal setae.

C o m p a r a t i v e n o t e s: Tetrabothrus brevalatus is readily distinguished from all other species recorded from China not only by the morphology of the aedeagus (shape of median lobe; longer paramere with longer apical lobe), but also by its larger size, the longer and more massive antennae, and particularly by the much shorter elytra, the reduced hind wings, and the reduced palisade fringe at the posterior margin of the abdominal tergite VIII. The geographically closest congeners with wings of reduced length are two species from Nepal and North India ( ASSING 2006), T. micropterus PACE, 1992 and T. curtipennis ASSING, 2006 , which differ from T. brevalatus by the different coloration of the legs alone (legs pale yellowish, with the femoral apices infuscate). For illustrations of T. micropterus and T. curtipennis see PACE (1992) and ASSING (2006), respectively.

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: The type locality is situated in the Xue Shan in West Yunnan ( Map 1 ). The specimens were sifted from leaf litter in a moist cleft with secondary pine forest with rhododendron undergrowth at an altitude of 2510 m.

Figures

Map 1: Distributions of Tetrabothrus species in China: T. puetzi (open triangle); T. inflexus (open circles); T. brevalatus (open star); T. cavus (filled circles); T. rubricollis (open diamond); T. chinensis (filled triangle).

Figs 18-23: Tetrabothrus brevalatus nov.sp.: forebody (18); antenna (19); abdomen (20); median lobe of aedeagus in lateral and in ventral view (21-22); paramere (23). Scale bars: 18, 20: 1.0 mm; 19: 0.5 mm; 21-23: 0.2 mm.