Atheta (Microdota) detruncata, Assing, 2006

Assing, V., 2006, Six new species of micropterous Atheta and Apimela from northern Yunnan, China (Coleoptera: Staphylinidae, Aleocharinae), Linzer biologische Beiträge 38 (2), pp. 1143-1156 : 1143-1156

Atheta (Microdota) detruncata nov.sp. ( Figs 37-44 )

Holotype ♀: China: N-Yunnan [C2005-12A], Nujiang Lisu Aut. Pref., Gongshan Co., Gaoligong Shan , 2500 m, 27°45.404'N, 98°35.749'E / litter and debries [sic] around snow sifted, 21.VI.2005, M. Schülke / Holotypus ♀ Atheta detruncata sp. n. det. V. Assing 2006 (cAss). Paratypes: 2♀♀: same data as holotype (cSch).

D e s c r i p t i o n: 2.3-2.6 mm. Habitus as in Fig. 37 . Coloration: head brown to dark brown, at least slightly darker than pronotum; pronotum and elytra brown; abdomen blackish, with segments III-IV slightly paler and segments VIII-X light brown; legs yel-

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lowish; antennae dark brown, with the basal 3-4 antennomeres yellowish to yellowish brown.

Head somewhat wedge-shaped, weakly transverse ( Fig. 38 ); eyes moderately large ( Fig. 39 ), slightly shorter than postocular region and weakly protruding from lateral outline of head in dorsal view; integument with distinct microreticulation; puncturation moderately dense, extremely fine, barely noticeable. Antenna distinctly incrassate apically ( Fig. 40 ); antennomere III slightly shorter than II; IV weakly transverse; V-X of increasing width and increasingly transverse; X approximately twice as wide as long.

Pronotum about 1.2 times as wide as long and approximately 1.1 times as wide as head ( Fig. 38 ); maximal width in anterior half; pubescence of midline directed cephalad in anterior half and apparently (not clearly visible in the three specimens available) caudad in posterior half; microsculpture and puncturation similar to those of head.

Elytra slightly wider than and at suture approximately 0.7 times as long as pronotum ( Fig. 38 ); microreticulation less distinct than that of head and pronotum; puncturation fine, but more distinct and denser than that of head and pronotum. Hind wings reduced.

Abdomen approximately as wide as or slightly wider than elytra, maximal width at segments V / VI ( Fig. 37 ); puncturation fine, moderately dense on anterior and sparse on posterior tergites; microreticulation distinct, but shallow; posterior margin of tergite VII with narrow palisade fringe.

Ƌ: unknown.

♀: tergite VIII with almost truncate posterior margin ( Fig. 41 ); sternite VIII somewhat longer than tergite VIII, its posterior margin distinctly convex and with row of distinctly modified setae ( Figs 42-43 ); spermatheca with very short duct ( Fig. 44 ).

E t y m o l o g y: The name (Lat., adj.) alludes to the short spermathecal duct.

C o m p a r a t i v e n o t e s: The species is readily distinguished from all other micropterous Chinese representatives of the subgenus by the shape of the spermatheca and by the shape and chaetotaxy of the female sternite VIII, from most species also by the larger eyes. The only Microdota species from China with a similarly short spermathecal duct are Atheta kadooriorum PACE from Hong Kong and A. yanensis PACE from Beijing. Apart from their longer and larger elytra and longer hind wings, they are separated from A. detruncata also by distinctly smaller size, as well as by their larger ( A. kadooriorum ) or smaller ( A. yanensis ) eyes and by the shape of the spermatheca. For illustrations of the habitus and the sexual characters of A. kadooriorum and A. yanensis see PACE (1998).

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 species is currently known only from one locality in the Gaoligong Shan, northern Yunnan, where the types were sifted near snow at an altitude of 2500 m. The type locality is illustrated in ASSING (in press: Fig. 40 ).

Figures

Figs 37-48: Atheta detruncata (37-44) and A. dimorpha (45-48): (37) ♀ habitus; (38) ♀ forebody; (39) head in lateral view; (40) antenna; (41, 47) ♀ tergite VIII; (42, 48) ♀ sternite VIII; (43) posterior margin of ♀ sternite VIII; (44) spermatheca; (45) Ƌ tergite VIII; (46) Ƌ sternite VIII. Scale bars: 37: 1.0 mm; 38: 0.5 mm; 39-42, 45-48: 0.2 mm; 43-44: 0.1 mm.