Rugilus (Rugilus) confluens ASSING 2012

Assing, V., 2013, A revision of Palaearctic and Oriental Rugilus. III. Five new species from the Palaearctic region and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 171-190 : 179

Rugilus (Rugilus) confluens ASSING 2012

( Figs 18-22 , Map 1 )

Material examined: China:Sichuan:2♂♂, 14♀♀, pass NW Songpan, 32°56'N, 103°26'E, 3600 m, moist N-slope with Salix and other shrubs, litter, grass roots, and moss sifted, 11.VIII.2012, leg. Assing, Schülke & Wrase ( cAss, cSch) ; 6♂♂ [1 macropterous], 9♀♀, N Songpan , road S 301, above Gan lake, 33°15'N, 103°46'E, 2700 m, spruce forest with birch, litter, mushrooms, moss, and dead wood sifted, 12.VIII.2012, leg. Assing, Schülke & Wrase ( cAss, cSch). Gansu: 2♂♂, 3♀♀ [partly teneral], W-Qinling Shan, NW Longnan, 34°03'N, 104°10'E, 2200 m, SW-slope with shrubs, litter sifted, 1.VIII.2012, leg. Assing, Schülke & Wrase ( cAss, cSch) ; 1♂, 6♀♀, W-Qinling Shan , NW Longnan, Lazikou pass, 34°14'32''N, 103°54'29''E, 3000 m, N-slope, pasture with shrubs, litter sifted, 2.VIII.2012, leg. Assing & Schülke ( cAss, cSch) ; 2♂♂, 2♀♀ [partly teneral], S Longnan , Min Shan, 33°03'13''N, 104°40'57''E, 2200 m, secondary pine forest with hazelnut, moist litter and roots sifted, 6.VIII.2012, leg. Assing, Schülke & Wrase ( cAss, cSch) .

Comment: Previously, R. confluens was known only from Sichuan and one doubtful record from northwestern Yunnan, and all examined specimens were micropterous. The above record of a macropterous male from northern Sichuan proves that, like R. gansuensis , R. parvincisus and some other species, R. confluens is wingdimorphic, which would explain why it is one of the more widespread representives of the subgenus Rugilus in China. Its currently known distribution ranges from southern Gansu across northern and western Sichuan probably into northern Yunnan ( Map 1 ). The only record from Yunnan, however, is based on a female. The distributions of R. confluens and R. gansuensis are apparently parapatric and roughly separated by the Bailong river.

The shape of the ventral process of the aedeagus is remarkably variable ( Figs 18-22 ). However, a re-examination of the different morphs revealed no plausible zoogeographic pattern suggesting that the current interpretation of R. confluens is a complex of several closely related species. Since the macropterous morph is apparently very rare, longdistance dispersal and, consequently, gene flow between populations probably occur infrequently, which would account for the observed variation. Therefore, the different shapes of the aedeagus are interpreted as an expression of intra- rather than interspecific variation.

Based on these findings, the possibility that R. meilixuensis from the Meilixue Shan in northern Yunnan ( Map 1 ), whose aedeagus is similar to that of R. confluens , too, will eventually prove to be conspecific with this species cannot be ruled out with certainty. However, the type specimens of R. meilixuensis are additionally distinguished by external characters such as the punctation of the head. Additional records and material from southern Sichuan and northern Yunnan are required to settle this problem.

The majority of the above males (including the macropterous specimen) and some females are at least slightly teneral. The sex ratio is biased in favour of females. Only 26 (26.5 %) in a total of 98 specimens are males.

Figures

Map 1: Distributions of Rugilus gansuensis ROUGEMONT (triangles), R. confluens ASSING (diamonds), R. meilixuensis ASSING (circles), and R. atronitidus nov.sp. (star), based on examined records. Filled symbols: male-based records; open symbols: female-based records.

Figs 13-22: Rugilus nitipennis nov.sp. (13-17) and R. confluens ASSING (18-22; 18: holotype from Sichuan, Qionglai Shan; 19: Sichuan, Jiajin Shan; 20, 22: Sichuan, environs of Songpan; 21: Gansu, Qinling Shan): (13) forebody; (14) male sternite VII; (15) male sternite VIII; (16, 18-22) aedeagus in lateral view; (17) aedeagus in ventral view. Scale bars: 13: 1.0 mm; 14-15: 0.5 mm; 16-22: 0.2 mm.