Tetrabothrus inflexus, Assing, 2015

Assing, Volker, 2015, On the Tetrabothrus fauna of China (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Linzer biologische Beiträge 47 (1), pp. 127-143 : 135-136

Tetrabothrus inflexus nov.sp. ( Figs 12-17 , Map 1 )

T y p e m a t e r i a l: Holotype Ƌ: " CHINA: Yunnan, Baoshan Pref., 10 km SE Kambaiti pass, 45 km NW Tengchong, 1700-1800 m, 25°21'13-29''N, 98°13'39-54''E, primary forest, litter and mushrooms sifted, 29.VIII.2009, leg. M. Schülke [ CH 09-15] / Holotypus Ƌ Tetrabothrus inflexus sp. n., det. V. Assing 2015" (cAss). Paratype Ƌ: " CHINA: Yunnan, Baoshan Pref., mount. range 25 km S Tengchong, 1900 m, 24°48'21''N, 98°32'05''E, cleft with devast. primary forest, litter & mushr. sifted, 30.VIII.2009, leg. M. Schülke [ CH 09-18]" (cSch).

E t y m o l o g y: The specific epithet is the past participle of the Latin verb inflectere (to bend) and alludes to the shape of the ventral process of the aedaegus in lateral view.

D e s c r i p t i o n: Species of variable body size; body length 4.5-5.6 mm; length of forebody 2.0- 2.4 mm. Coloration: body brown to dark-brown, with the posterior margins of the abdominal segments reddish; legs yellowish, with the apices of the femora narrowly and indistinctly infuscate; antennae blackish-brown, with antennomeres II and III dark-reddish.

Head ( Fig. 12 ) approximately 1.2 times as broad as long; posterior angles weakly marked; punctation extremely fine and sparse; median dorsal portion impunctate; pubescence greyish and suberect; microsculpture absent. Eyes large and bulging, but noticeably shorter than distance from posterior margin of eye to posterior constriction of head in dorsal view. Antenna 1.1-1.3 mm long and shaped as in Fig. 13 .

Pronotum ( Fig. 12 ) transverse, 1.1 times as broad as long and 1.07-1.13 times as broad as head, broadest in posterior half, narrowly margined; lateral margins nearly straight in dorsal view; posterior angles rounded, but noticeable; anteriorly strongly tapering, anterior angles not visible in dorsal view; punctation sparse and very fine; midline broadly impuncate; pubescence greyish and suberect; microsculpture absent.

Elytra ( Fig. 12 ) nearly as long as pronotum; punctation and pubescence similar to those of pronotum; interstices without microsculpture. Hind wings present. Metatibia 0.75- 0.92 mm long; metatarsus 0.62-0.68 times as long as metatibia; metatarsomere I slightly shorter than the combined length of II and III.

Abdomen ( Fig. 14 ) narrower than elytra, broadest at tergites III-V; tergites III-VI with deep anterior impressions, the impression of tergite VI as deep as that of tergite V; tergites III-VII without microsculpture and impunctate except for few punctures bearing long dark setae at the posterior margins; tergite VIII with thin and moderately long yellowish setae in posterior portion, posterior margin weakly convex; posterior margin of tergite VII with pronounced palisade fringe.

Ƌ: sternite VIII transverse and with strongly convex posterior margin; median lobe of aedeagus ( Figs 15-16 ) of very variable size, 0.38-0.48 mm long; ventral process short and strongly angled in the middle and in lateral view; paramere ( Fig. 17 ) 0.53-0.58 mm long, with moderately slender and moderately long apical lobe.

♀: unknown.

C o m p a r a t i v e n o t e s: Tetrabothrus inflexus differs from other congeners recorded from China by the conspicuous morphology of the median lobe of the aedeagus. It is additionally distinguished from the externally similar T. cavus by the coloration of the femora, the slightly more slender pronotum, the less deep anterior impressions of the abdominal tergites III-VI, and by the smaller parameres with shorter and less slender apical lobes. Based on the similar morphology of the aedeagus (shapes of ventral process, internal sac, and internal structures), T. inflexus is closely allied to T. malaysianus PACE, 2013 , from which it is additionally distinguished by greater body size ( T. malaysianus : 4.0 mm), the different coloration of the antennae, the smaller eyes, the absence of coarse punctures at the base of the abdominal tergite VII, and the absence of fossae on the male tergite VIII. For illustrations of T. cavus and T. malaysianus see Figs 1-11 and PACE (2013b), respectively.

The new species differs from T. nepalensis , with which it shares a strongly angled ventral process of the aedeagus, by distinctly shorter and less massive antennae ( T. nepalensis : antenna approximately 1.6 mm long), the shape of the pronotum ( T. nepalensis : anterior angles not clearly visible in dorsal view), the apically narrowly and indistinctly infuscate femora ( T. nepalensis : femora apically broadly and distinctly infuscate), by the smaller median lobe of the aedeagus with an internal sac of different shape), and by the distinctly smaller parameres ( T. nepalensis : paramere approximately 0.75 mm long). For illustrations of T. nepalensis see PACE (1992).

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 known distribution is confined to two localities in northwestern Yunnan, one of them close to the border with Burma ( Map 1 ). The specimens were sifted from litter in primary forests at altitudes between 1700 and 1900 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 12-17: Tetrabothrus inflexus nov.sp.: forebody (12); antenna (13); abdomen (14); median lobe of aedeagus in lateral and in ventral view (15-16); paramere (17). Scale bars: 12, 14: 1.0 mm; 13: 0.5 mm; 15-17: 0.2 mm.

Figs 1-8: Tetrabothrus cavus nov.sp. from Yunnan (1-7) and Shaanxi (8): forebody (1); antenna (2); abdomen (3); male tergite VIII (4); male sternite VIII (5); paramere (6); female sternite VIII (7- 8). Scale bars: 1, 3: 1.0 mm; 2, 4-5, 7-8: 0.5 mm; 6: 0.2 mm.

Figs 9-11: Tetrabothrus cavus nov.sp. from western (9) and eastern Yunnan (10-11): median lobe of aedeagus in lateral view (9-10); median lobe of aedeagus in ventral view (11). Scale bar: 0.2 mm.