Diartiger yaoluopingensis, Yin, Zi-Wei & Li, Li-Zhen, 2013

Yin, Zi-Wei & Li, Li-Zhen, 2013, Notes on synonymy of Diartiger Sharp with Microdiartiger Sawada (Coleoptera: Staphylinidae: Pselaphinae), with description of two new species from East China, Zootaxa 3717 (3), pp. 369-376 : 370

Relationship of Diartiger with Microdiartiger

Kôhei Sawada (1964) erected Microdiartiger Sawada for his new species M. japonicus Sawada from Japan. He separated the new genus from Diartiger by the presence of sparse, thick, suberect setae on the head and pronotum (instead of dense fine setae in Diartiger ), the presence of microsculpture on elytra (microsculpture absent in Diartiger ), less developed trichomes on elytra and abdomen, and mesotrochanters lacking ventral spine (spinose mesotrochanters in Diartiger ).

Besuchet (1986: 263) placed Microdiartiger as a junior synonym of Diartiger , he stated (our translation of French text to English): ‘In my opinion, the genera Diartiger and Microdiartiger belong to the same genus, they differ only in size and a few minor characters, thus the latter is only a synonym of the former’.

Nomura (1997) followed Besuchet’s placement in his revision of Diartiger . In a later revision of Microdiartiger (Nomura 2007) , he discussed the monophyly of these two genera, and resurrected the generic status of Microdiartiger . In 2010, the first species of Microdiartiger from China, M. songxiaobini Yin & Li was described (Yin, Li & Zhao 2010) from Tianmushan Mountain in the Zhejiang Province.

During the present study, we found that Diartiger yaoluopingensis sp. n. has elytra that bear distinct linear microsculpture. This character state blurs the definitions of Diartiger and Microdiartiger . Other characters used by Sawada (see above) are either highly variable in clavigerite genera, or are male sexual features which cannot be used to support Microdiartiger as a distinct genus. Hence we follow the synonymy proposed by Besuchet (1986), and transfer two species from Microdiartiger to Diartiger : Diartiger thinhi (Nomura) and Diartiger songxiaobini (Yin & Li), new combinations. Members of Diartiger are here placed in two groups: the D. japonicus -group, including the species previously placed in Microdiartiger , and the D. fussulatus -group, containing all remaining species.