Orsunius yunnanus, Assing, 2011

Assing, V., 2011, Orsunius gen. nov. from the Oriental region (Coleoptera: Staphylinidae: Paederinae: Medonina), Linzer biologische Beiträge 43 (1), pp. 221-244 : 226-228

Orsunius yunnanus nov.sp. ( Figs 15-19 )

T y p e m a t e r i a l: Holotype Ƌ: " China: N-Yunnan [C2005-15], Nujiang Lisu Aut. Pref., Gongshan Co., Gaoligong Shan , small creek valley 17 km N Gongshan / 27°54.41'N, 98°39.55'E, 1525-1600 m, along creek under stones, gravel, leaf litter, sifted, 20.VI.2005, M. Schülke [C2005- 15] / Holotypus Ƌ Orsunius yunnanus sp.n. det. V. Assing 2011" (cAss) . Paratypes: 5 exs.: same data as holotype (cSch, cAss) ; 3 exs.: " China: Yunnan [CH07-18], Baoshan Pref., mountain range 22 km S Tengchon , 1750 m, 24°49'29''N, 98°29'27''E, second. forest, litter, dead wood sifted, 2.VI.2007, leg. A. Pütz " (cPüt, cAss); 1 ex.: " China: Yunnan [CH07-25], Nujiang Lisu Aut. Pref. Salween side valley 5 km S Fugong, road SS 228 km 223, under stones, moist embankment, 8.VI.2007, leg. A. Pütz " (cPüt) .

D e s c r i p t i o n: Body length 4.3-5.0 mm. Habitus as in Fig. 15 . Coloration: head reddish-brown to dark-brown; pronotum reddish to reddish-brown; elytra dark-brown, with the anterior margins, the suture, and the posterior margins reddish, rarely uniformly reddish; abdomen reddish to reddish-brown, with the middle of tergite VII infuscate; legs and antennae reddish.

Head of transversely rectangular shape, approximately 1.2 times as broad as long ( Fig. 16 ); punctation coarse and dense, posterior median portion of dorsal surface with small area without, or with sparse punctation; interstices glossy, in most of dorsal surface distinctly narrower than diameter of punctures; sides with numerous long blackish setae. Eyes large and bulging, slightly longer than postocular portion in dorsal view. Gular sutures separated by a distance greater than the width of antennomere III.

Pronotum approximately 1.2 times as wide as long and approximately 1.05 times as broad as head ( Fig. 16 ); posterior angles rounded, weakly marked; lateral margins visible only in posterior two thirds when viewed from above; punctation similar to that of head or slightly less coarse; midline broadly impunctate; lateral and anterior margins with numerous long black setae.

Elytra approximately 1.1 times as long as pronotum ( Fig. 16 ); punctation very dense and fine; interstices without microsculpture. Hind wings fully developed. Protarsomeres I-IV strongly dilated. Metatarsomere I longer than II and slightly shorter than the combined length of II and III.

Abdomen narrower than elytra; punctation extremely fine, dense on anterior tergites and somewhat sparser on posterior tergites; interstices with distinct microsculpture; posterior margin of tergite VII with palisade fringe.

Ƌ: sternite VII not distinctly modified; sternite VIII with truncate posterior margin ( Fig. 17 ); aedeagus 0.90-0.95 mm long; ventral process large, laterally compressed, somewhat asymmetric in ventral view, and with apex of distinctive shape ( Figs 18-19 ).

E t y m o l o g y: The specific epithet (adjective) is derived from the name of the Chinese province where the species was discovered.

C o m p a r a t i v e n o t e s: Based on the similarly derived morphology of the aedeagus, as well as on the similar external and male secondary sexual characters (relatively large size, punctation of forebody, strongly dilated protarsomeres I-IV, slender antennae, posteriorly truncate male sternite VIII), O. yunnanus is closely related to the similar O. wunderlei , from which it is distinguished particularly by the darker coloration of the head and pronotum, the distinctly bicoloured elytra, the less transverse pronotum, the slightly less dense punctation of the abdomen, and especially by the differently shaped ventral process of the aedeagus.

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: Orsunius yunnanus is currently known from three localities in Yunnan, China. The specimens were collected by sifting leaf litter and dead wood in a secondary forest and near a stream, and from under stones near water at altitudes of 1525-1750 m in June.

Figures

Figs 12-19: Orsunius wunderlei nov.sp. (12-14) and O. yunnanus nov.sp. (15-19): (12) left mandible; (13) right mandible; (14, 17) male sternite VIII; (15) habitus; (16) forebody; (18) aedeagus in lateral view; (19) apical portion of ventral process in lateral view. Scale bars: 15: 1.0 mm; 16: 0.5 mm; 12-14, 17-19: 0.2 mm.