Wumengius, Tian & Huang & Jia, 2023

Tian, Mingyi, Huang, Sunbin & Jia, Xinyang, 2023, A contribution to cavernicolous beetle diversity of South China Karst: eight new genera and fourteen new species (Coleoptera: Carabidae: Trechini), Zootaxa 5243 (1), pp. 1-66 : 10-11

Wumengius n. gen.

Type species: Wumengius fengi n. sp. (Da Dong, Duge, Liupanshui, Guizhou)

Generic characteristics. Medium-sized for cave trechines;anophthalmic,body moderately elongate,surface glabrous though genae with sparse setae. Head slightly longer than wide, sides sub-parallel-sided; neck short, constriction well-marked; presence of two pairs of supraorbital setiferous pores; frontal furrows well-marked, strongly divergent anteriorly and posteriorly; frons and vertex convex; clypeus quadrisetose, labrum strongly bisinuate at margin; mandibles moderately developed, feebly curved apically, right mandibular tooth tridentate; mentum and submentum completely fused, mentum bisetose, base largely concave, each side with a long setae; tooth moderately long, rather widened and faintly bifid at tip; submentum with a row of 9 setae; 2 nd labial palp with only a seta on inner margin; antennae short, extending only at about apical 3/5 of elytra. Prothorax not tumid, propleura invisible from above; pronotum subcordate, as long as head including mandibles, widest at about 5/7 from base, fore angles protruding, hind angles nearly rectangular, pointed; base nearly straight; presence of only the anterior pair of latero-marginal setae; disc moderately convex. Elytra elongated ovate, longer than head plus pronotum, widest at about middle, humeral angles completely rounded off; lateral margins sub-serrate near base, ciliate throughout; disc strongly convex, striae fine and deep, intervals slightly convex; apical striole absent; presence of two dorsal and the preapical pores; 1 st, 2 nd and 6 th marginal umbilicate pores near marginal gutter; humeral set aggregated, median set close to each other. Protarsomeres not modified in male; tibiae longitudinally sulcate. Male genitalia weakly sclerotized, thin and elongated, slightly arcuate medially; base small and narrow, with a large sagittal aileron, apical lobe slightly reflexed; parameres moderately developed, much shorter than the median lobe.

Remarks. Wumengius n. gen. is a peculiar genus regarding its non-dilated protarsi in male, basal foveae of mentum with a pair of setae, the 2 nd labial palp unisetose on inner margin and labrum deeply bisinuate at frontal margin. The well-defined frontal furrows and elytral chaetotaxal pattern indicate that it is an anophthalmic type species. It differs from Guizhaphaenops (Vigna Taglianti 1997, Uéno 2000), a semi-aphaenopsian genus ranging in northwestern Guizhou and northeastern Yunnan, by the completefrontal furrows (vs partially reduced in Guizhaphaenops ), subcordate pronotum (vs round-ovate in Guizhaphaenops ), and aggregated humeral set of the marginal umbilicate pores (not aggregated in Guizhaphaenops ).

Wumengius n. gen. is different from Dongoblemus Deuve & Tian 2016 , distributed in Kema Dong of Zhenxiong which is not far from Da Dong, by: (1) maxillary palp 3 glabrous, vs. with several setae in Dongoblemus ; (2) each side of basal fovea of mentum with a seta, vs. no basal foveal seta in Dongoblemus ; (3) Mandibular tooth tridentate, vs. bidentate in Dongoblemus ; (4) pronotum without hind latero-marginal pores, which are present in Dongoblemus ; and dorsal pores of elytra on stria 3, vs. on stria 4 in Dongoblemus .

Etymology. Refers to the Mts. Wumeng which ranges in western Yunnan and northwestern Guizhou province. Gender masculine.

Range. China (Guizhou).