Atheta (Microdota) foliacea, 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) foliacea nov.sp. ( Figs 14-26 )

Holotype Ƌ: China: N-Yunnan [C2005-05], Diqing Tibet. Aut. Pref., Zhongdian Co., Xue Shan near lake 23 km S Zhongdian, 3895 m / 27°37.1'N, 99°38.5'E, devast. mixed forest, meadows, lake border, leaf litter, dead wood, sifted, 5.VI.2005, leg. M. Schülke [C2005-05] / Holotypus Ƌ Atheta foliacea sp. n. det. V. Assing 2006 (cAss). Paratypes: 5 exs.: same data as holotype (cSch, cAss).

D e s c r i p t i o n: 2.4-2.9 mm. Habitus as in Fig. 14 . Coloration: head brown to blackish brown; pronotum and elytra brown to dark brown; abdomen blackish brown, with the apex slightly paler; legs light brown; antennae brown, with the basal 3-4 antennomeres yellowish to yellowish brown.

Head, with sexual dimorphism, slightly wider than long, of suborbicular shape ( Fig. 15 ); eyes very small, composed of only approximately 10 ommatidia ( Fig. 16 ), not protruding from lateral outline of head, less than 1/4 the length of postocular region in dorsal view; integument with distinct microreticulation and almost matt; puncturation sparse, fine, and very shallow, barely noticeable in the microsculpture. Antenna distinctly incrassate apically ( Fig. 17 ); antennomere III distinctly shorter than II; IV weakly transverse; V-X of increasing width and increasingly transverse; X approximately twice as wide as long.

Pronotum, with sexual dimorphism, 1.15-1.20 times as wide as long and approximately 1.15 times as wide as head ( Fig. 15 ); maximal width in anterior half; pubescence of midline directed cephalad in anterior half and caudad in posterior half; puncturation and microsculpture similar to those of head.

Elytra with sexual dimorphism, 1.05-1.10 times as wide and at suture less than 0.6 times as long as pronotum ( Fig. 15 ); microreticulation pronounced, puncturation denser and slightly more distinct than that of head and pronotum. Hind wings reduced.

Abdomen slightly (1.10-1.15 x) wider than elytra, maximal width at segments V / VI ( Fig. 14 ); puncturation fine, much sparser on posterior than on anterior tergites; microreticulation distinct; posterior margin of tergite VII with very narrow rudiment of a palisade fringe.

Ƌ: head and pronotum with extensive median impressions ( Fig. 15 ); elytra on either side of suture somewhat elevated ( Fig. 15 ); posterior margin of tergite VIII broadly concave

1147

in the middle ( Fig. 18 ); sternite VIII much longer than tergite VIII, its posterior margin strongly convex ( Fig. 19 ); median lobe of aedeagus with thin, blade-like ventral process ( Figs 22-23 ); apical lobe of paramere shaped as in Fig. 24 , with three relatively short setae.

1148

♀: head and pronotum without or with very indistinct impressions; elytra not distinctly elevated on either side of suture; tergite VIII similar to that of Ƌ ( Fig. 20 ); sternite VIII longer than tergite VIII, its posterior margin in the middle distinctly concave and with distinctly modified marginal setae ( Fig. 21 ); spermatheca as in Figs 25-26.

E t y m o l o g y: The name (Lat., adj.: shaped like a leaf) refers to the thin ventral process of the aedeagus.

C o m p a r a t i v e n o t e s: Based on the modifications of the male head and pronotum, as well as on the morphology of the aedeagus, A. foliacea is very closely related to A. elisa from the Daba Shan in Shaanxi. From this species, A. foliacea is distinguished especially by the darker coloration of the forebody, the less pronounced impressions on the male head and pronotum, the modified male elytra, the different shapes of tergite and sternite VIII in both sexes, the more evenly curved (lateral view), broader and apically less acute (ventral view) ventral process of the aedeagus, as well as by the slightly differently shaped spermatheca. For illustrations of the sexual characters of A. elisa see ASSING (2002). From the syntopic A. xueica , A. foliacea is readily separated by much paler coloration of the forebody and the appendages, by the more transverse antennomeres IV-X, the much smaller eyes, the subcircular head shape, the sexual dimorphism of head, pronotum, and elytra, the smaller and less transverse pronotum, the distinctly shorter elytra, the narrow rudiment of a palisade fringe at the posterior margin of tergite VII, the different shapes of tergite and sternite VIII in both sexes, as well as by the completely different morphology of the primary sexual characters; for comparison see Figs 1-14.

D i s t r i b u t i o n a n d b i o n o m i c s: Thetypelocality is situated in the Xue Shan in northern Yunnan; for an illustration see ASSING (2006: Fig. 20 ). The specimens were sifted from the forest floor in a mixed forest at an altitude of approximately 3900 m.

Figures

Figs 14-26: Atheta foliacea: (14) Ƌ habitus; (15) Ƌ forebody; (16) head in lateral view; (17) antenna; (18) Ƌ tergite VIII; (19) Ƌ sternite VIII; (20) ♀ tergite VIII; (21) ♀ sternite VIII; (22-23) median lobe of aedeagus in lateral and in ventral view; (24) apical lobe of paramere; (25-26) spermatheca. Scale bars: 14: 1.0 mm; 15: 0.5 mm; 16-21: 0.2 mm; 22-26: 0.1 mm.

Figs 1-13: Atheta xueica: (1) habitus; (2) forebody; (3) head in lateral view; (4) antenna; (5) Ƌ tergite VIII; (6) Ƌ sternite VIII; (7) posterior margin of ♀ tergite VIII; (8) ♀ sternite VIII; (9-10) median lobe of aedeagus in lateral and in ventral view; (11) apex of median lobe of aedeagus in ventral view; (12) apical lobe of paramere; (13) spermatheca. Scale bars: 1: 1.0 mm; 2-3: 0.5 mm; 4-8: 0.2 mm; 9-13: 0.1 mm.