Masuria (Oncosomechusa) schuelkei, Assing, 2012

Assing, V., 2012, On the taxonomy of Masuria. IV. Four new species from China and Nepal, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 44 (2), pp. 1017-1034 : 1025-1027

Masuria (Oncosomechusa) schuelkei nov.sp. ( Figs 10-16 , Map 1 )

T y p e m a t e r i a l: Holotype: " China: N-Sichuan [CH12-22], Min Shan , pass 17 km NE Songpan, 32°44'54''N, 103°43'43''E, 4080 m, W-slope with scree and shrubs, litter and moss sifted, 10.VIII.2012, leg. M. Schülke / Holotypus Masuria schuelkei sp.n. det. V. Assing 2012" (cAss).

E t y m o l o g y: The species is dedicated to my friend and colleague Michael Schülke, who collected the holotype.

D e s c r i p t i o n: Body length 2.3 mm; length of forebody 1.0 mm. Habitus as in Fig. 10 . Coloration: head brown; pronotum and elytra reddish-yellow; abdomen darkbrown with indistinctly paler apex; legs yellowish; antennae pale-brown, with the basal 3 antennomeres reddish-yellow.

Head ( Fig. 11 ) distinctly transverse; punctation sparse and fine, but noticeable; interstices without microreticulation; eyes relatively small and weakly projecting from lateral contours of head, shorter than postocular region in dorsal view. Antenna relatively short, 0.75 mm long, moderately slender, and moderately incrassate apically; antennomere III distinctly shorter than II; IV indistinctly oblong, V weakly transverse, VI-X of gradually increasing width and increasingly transverse, X less than twice as wide as long.

Pronotum ( Figs 11-12 ) relatively large and distinctly convex in cross-section, approximately 1.35 times as wide as long and 1.3 times as wide as head; maximal width approximately in the middle; posterior angles rounded, weakly marked; punctation moderately fine and distinct; interstices with traces of microsculpture visible only at high magnification, glossy; pubescence of midline directed caudad.

Elytra ( Figs 11, 13 ) at posterior margin approximately as broad as pronotum, posteriorly distinctly widened, and very short, 0.50 times as long as pronotum; punctation somewhat granulose and slightly more distinct than that of pronotum; microsculpture absent. Hind wings completely reduced. Legs moderately slender; metatarsomere I nearly as long as the combined length of II-IV.

Abdomen broad, widest at segment V; punctation rather dense, moderately fine, and distinct; microsculpture absent ( Fig. 14 ); posterior margin of tergite VII without palisade fringe.

: posterior margins of tergite and sternite VIII strongly convex; median lobe of aedeagus ( Fig. 15 ) 0.4 mm long, at base of ventral process with pair of carinae.

: unknown.

C o m p a r a t i v e n o t e s: Masuria schuelkei is readily distinguished from M. appendiculata , its geographically closest congener, by the near absence of microsculpture on the whole body, by the much more distinct punctation of the forebody, by the shorter and less slender antennae and legs, as well as by the different morphology of the aedeagus. It is separated from M. chinensis from Gansu by smaller body size ( M. chinensis : length of forebody approximately 1.2 mm), the more slender body, particularly the more slender abdomen ( M. chinensis : abdomen broader than elytra), by the absence of microsculpture on the abdomen, and by the different shape of the median lobe of the aedeagus (ventral process less strongly bent, carinae instead of appendages at base of ventral process, crista apicalis of different shape).

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 locality is situated 17 km to the northeast of Songpan in northern Sichuan ( Map 1 ). The specimens were sifted from shrub litter and moss in a subalpine shrub habitat at an altitude of 4080 m ( Fig. 16 ).

Figures

Map 1: Distribution of Masuria species in China: M. chinensis PACE (white diamond); M. appen- diculata nov.sp. (black triangle); M. schuelkei nov.sp. (white triangle); M. brevipennis ASSING (black circle); M. yunnanica ASSING (white circles); M. subnitens nov.sp. (black diamond); M. daliensis ASSING (white square).

Figs 10-15: Masuria schuelkei nov.sp.: (10) habitus; (11) forebody; (12) median dorsal portion of pronotum; (13) median portion of elytra; (14) median portion of abdominal tergite VII; (15) median lobe of aedeagus in lateral view. Scale bars: 10: 1.0 mm; 11: 0.5 mm; 3: 0.2 mm; 12-15: 0.1 mm.

Fig. 16: Type locality of Masuria schuelkei nov.sp..