Tropimenelytron sinuosum, Assing, 2011

Assing, V., 2011, Six new species and additional records of Aleocharinae from China (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 43 (1), pp. 291-310 : 299-301

Tropimenelytron sinuosum nov.sp. ( Figs 20-23 , 33-35 )

T y p e m a t e r i a l: Holotype: " China: Yunnan, Baoshan Pref., Gaoligong Shan , 32 km SE Tengchong, 2150-2250 m, 24°51-53'N, 98°45'E, devast. prim. and second. forest, litter, dead wood, mushrooms sifted, 26.VIII.2009, leg. M. Schülke [CH09-08/09] / Holotypus Tropimenelytron sinuosum sp. n. det. V. Assing 2010" (cAss). Paratypes: 2: same data as holotype (cSch); 1, 1: " China (Yunnan) Pu´er Pref., Ailao Shan , 37 km NW Jingdong, 24°45'12''N, 100°41'24.5''E, 2300 m (devastated forest remnant, litter/moss/grass roots sifted, 13.IX.2009, D. W. Wrase [48]" (cSch, cAss); 1: " China: Yunnan, Lincang Pref., Wuliang Shan, old pass road, W side, 24°42'58.6''N, 100°29'52.0''E, 2200 m, small creek valley with primary forest remnant, litter & debris sifted, 12.IX.2009, M. Schülke [CH09-47]" (cSch).

D e s c r i p t i o n: Body length 3.0-4.0 mm. Coloration: head, pronotum, and abdomen (except for the paler apex) blackish; elytra yellowish, with the scutellar region and the postero-lateral angles diffusely and more or less extensively infuscate, rarely most of elytra dark; legs yellowish; antennae blackish-brown.

Head ( Fig. 20 ) approximately as wide as long; punctation sparse and extremely fine, barely noticeable; interstices with very shallow microsculpture, glossy. Eyes large, approximately twice as long as postocular region in dorsal view. Antenna slender; antennomere IV weakly transverse; V-X gradually and weakly increasing in width; X approximately 1.5 times as wide as long; XI approximately as long as the combined length of IX and X.

Pronotum ( Fig. 20 ) with sexual dimorphism, slender, approximately 1.20-1.25 times as wide as head; posterior angles weakly marked; punctation sparse and very fine, but more distinct than that of head; on either side of middle with two larger punctures, the four punctures approximately forming a square or an oblong rectangle; surface with shallow microsculpture and glossy.

Elytra ( Fig. 20 ) with pronounced sexual dimorphism, 0.8 (large male) to 0.95 (female) times as long as, and much broader than pronotum; humeral angles pronounced; punctation fine and dense; interstices with shallow microsculpture. Hind wings fully developed.

Abdomen with very sparse punctation and transverse microsculpture, glossy; posterior margin of tergite VIII with palisade fringe.

: pronotum approximately as long as wide and produced posteriorly, middle of dorsal surface flattened (only in large male), posterior margin pointed in the middle ( Fig. 20 ); elytra with enormous sinuose carinae on either side of middle, extending well beyond middle of suture ( Fig. 20 ); tergite VII near posterior margin with smooth median tubercle ( Fig. 33 ); posterior margin of tergite VIII truncate, serrulate, and with marked lateral angles; sternite VIII broadly convex posteriorly; median lobe of aedeagus 0.35-0.38 mm long, shaped as in Figs 21-22 .

: pronotum approximately 1.05 times as wide as long, posterior margin weakly convex; elytra and abdominal tergite VII without modifications; tergite VIII broadly and weakly convex posteriorly ( Fig. 34 ); posterior margin of sternite VIII distinctly concave in the middle ( Fig. 35 ); spermatheca as in Fig. 23.

I n t r a s p e c i f i c v a r i a t i o n: The somewhat smaller male paratype has less pronounced male secondary sexual characters than the holotype; the pronotum is not flattened in the middle and posteriorly less distinctly pointed, the sutural carinae are slightly less conspicuous, and the median tubercle at the posterior margin of the abdominal tergite VIII is smaller.

E t y m o l o g y: The name (Latin, adjective) refers to the conspicuous sinuose carinae on the male elytra.

C o m p a r a t i v e n o t e s: In both external and sexual characters, T. sinuosum is most similar to T. viaticum , from which it is readily distinguished by the distinctly larger eyes ( T. viaticum : eyes only slightly longer than postocular region), the much less pronounced microsculpture of the head and pronotum ( T. viaticum : microreticulation pronounced, surface only with subdued shine), the modifications of the male pronotum and elytra ( T. viaticum : posterior margin of pronotum weakly convex; elytral carinae short, weakly elevated, and straight), the smaller and differently shaped aedeagus, the distinct median concavity of the posterior margin of the female sternite VIII ( T. viaticum : very weakly concave), and the slightly different shape of the spermatheca. For illustrations of T. viaticum see Figs 24-27 and PACE (1998c).

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 specimens were collected in three localities in Yunnan, by sifting litter in primary forest remnants and secondary forests at altitudes of 2150-2300 m.

Figures

Figs 20-27: Tropimenelytron sinuosum nov.sp. (20-23) and T. viaticum PACE, paratype (24-27): (20, 24) forebody; (21, 27) median lobe of aedeagus in lateral view; (22) median lobe of aedeagus in ventral view; (23) spermatheca; (25) male tergite VIII; (26) male sternite VIII. Scale bars: 20, 24: 0.5 mm; 25-26: 0.2 mm; 21-23, 27: 0.1 mm.

Figs 28-37: Bellatheta diacangica nov.sp. (28-32), Tropimenelytron sinuosum nov.sp. (33-35), and Oroekklina excaecata (ASSING) (36-37): (28) habitus; (29) forebody; (30-31) median lobe of aedeagus in lateral and in ventral view; (32) spermatheca; (33) male tergites VI-VII; (34) female tergite VIII; (35) female sternite VIII; (36) male tergite VIII; (37) male sternite VIII. Scale bars: 28: 1.0 mm; 29, 33: 0.5 mm; 34-37: 0.2 mm; 30-32: 0.1 mm.