Masuria (Oncosomechusa) subnitens, 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 : 1027-1030

Masuria (Oncosomechusa) subnitens nov.sp. ( Figs 17-25 , Map 1 )

T y p e m a t e r i a l: Holotype: " China: Yunnan [CH07-21], Nujiang Lisu Auton. Pref., Gaoligong Shan , pass 22 km W Gongshan, N slope, 3350-3400 m, 27°46'27"N, 98°26'50"E, fern, moss, litter, sifted, 6.VI.2007, M. Schülke / Holotypus Masuria subnitens sp.n. det. V. Assing 2007" (cAss) . Paratypes: 16 exs.: same data as holotype (cSch, cAss) ; 3 exs., same data as holotype, but leg. A. Pütz (cPüt, cAss) .

E t y m o l o g y: The specific epithet (Latin, adjective) refers to the subdued shine of the forebody, one of the characters separating this species from other consubgeners known from Yunnan.

D e s c r i p t i o n: Body length 2.2-2.6 mm; length of forebody 1.0- 1.2 mm. Habitus as in Fig. 17 . Coloration: head and abdomen blackish, except for the dark-brown posterior part of segment VIII and the following segments; pronotum and elytra brown to dark-brown; legs dark-reddish; antennae dark-brown with the basal 3-4 antennomeres reddish.

Head ( Fig. 18 ) with extremely fine, barely noticeable punctation and with distinct microreticulation; eyes relatively small and weakly projecting from lateral contours of head, approximately as long as postocular region in dorsal view or slightly shorter. Antenna ( Fig. 19 ) 0.8-1.0 mm long, relatively slender and moderately incrassate apically; antennomere IV weakly oblong, V approximately as wide as long, VI weakly transverse, VI-X of gradually increasing width and increasingly transverse, X less than twice as wide as long.

Pronotum ( Fig. 18 ) relatively large and distinctly convex in cross-section, 1.25-1.30 times as wide as long and approximately 1.3 times as wide as head; maximal width approximately in the middle; posterior angles rounded, weakly marked; punctation usually extremely fine and shallow, barely noticeable, rarely more distinct; microsculpture similar to that of head, usually pronounced, rarely very shallow; integument usually with weak shine; pubescence of midline directed caudad.

Elytra ( Fig. 18 ) only indistinctly wider than pronotum and very short, at suture approximately 0.5 times as long as pronotum; punctation as fine as that of pronotum or slightly more distinct; microsculpture usually shallower than that of pronotum. Hind wings reduced. Legs relatively short; metatarsomere I elongated, slightly longer than the combined length of II-IV.

Abdomen broad, approximately 1.1 times as wide as elytra and widest at segment V; punctation rather dense, fine, and weakly granulose; microsculpture somewhat variable, but usually pronounced; posterior margin of tergite VII without palisade fringe.

: posterior margin of tergite VIII broadly and weakly convex, in the middle weakly concave ( Fig. 20 ); sternite VIII distinctly longer than tergite VIII, its posterior margin broadly convex ( Fig. 21 ); median lobe of aedeagus ( Fig. 22 ) approximately 0.55 mm long.

: tergite VIII of similar shape as that of male ( Fig. 23 ); sternite VIII longer than tergite VIII, but shorter than male sternite VIII, posteriorly produced, in the middle weakly concave, almost truncate, and with row of stout pale-coloured marginal setae ( Fig. 24 ); spermatheca as in Fig. 25.

C o m p a r a t i v e n o t e s: Masuria subnitens is separated from all its congeners by the morphology of the aedeagus. From M. brevipennis and M. yunnanica , its geographically closest congeners, it is additionally distinguished as follows:

from M. brevipennis by the presence of distinct microsculpture on the head and pronotum, the extremely fine punctation on the head and pronotum, and by the more slender antennae with antennomere IV not transverse;

from M. yunnanica by the much shorter elytra ( M. yunnanica : approximately 0.7 times as long as pronotum), the differently shaped pronotum ( M. yunnanica : widest in anterior half), the weakly marked posterior angles of the pronotum (obtusely marked in M. yunnanica ), the much finer punctation and shorter pubescence of the forebody, the much smaller eyes ( M. yunnanica : eyes more convex and slightly longer than postocular region

in dorsal view), the straight posterior margins of the elytra ( M. yunnanica : sinuate near posterior angles), and by the distinctly finer and shorter antennae.

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: Thetypelocalityissituatedin the Gaoligong Shan, western Yunnan province ( Map 1 ). The types were collected by sifting litter, moss, and fern at an altitude of approximately 3400 m.

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 17-25: Masuria subnitens nov.sp.: (17) habitus; (18) forebody; (19) antenna; (20) male tergite VIII; (21) male sternite VIII; (22) median lobe of aedeagus in lateral view; (23) female tergite VIII; (24) female sternite VIII; (25) spermatheca. Scale bars: 17: 1.0 mm; 18: 0.5 mm; 19-21, 23-24: 0.2 mm; 22: 0.1 mm; 25: 0.05 mm.