Miaotrechus, Tian & Chen & Ma, 2020

Miaotrechus View in CoL n. gen.

Type species. Miaotrechus mahua View in CoL n. sp. (cave Miaoting, Getuhe cave system, Ziyun, southern Guizhou).

Generic characteristics. Small to medium-sized, Anophthalmus-like beetles, eyeless; body depigmented, palps short, antennae and legs moderately long; head and pronotum glabrous ( M. mahua n. sp.) or with a few sparse setae ( M. heweii n. sp.), elytra glabrous ( M. mahua n. sp.) or with short pubescence ( M. heweii n. sp.); head subquadrate, longer than wide, and as long as pronotum (excluding mandibles); frontal furrows entire, two pairs of supraorbital and a pair of suborbital pores present; right mandible tridentate; mentum and submentum completely fused; median tooth short, bifid at tip; antennae extending to about apical 1/3 ( M. mahua n. sp.) or 1/4 ( M. heweii n. sp.) of elytra; propleura invisible from above; pronotum quadrate, two pairs of latero-marginal setae present; elytra moderately convex, shoulders broadly rounded, lateral margins ciliate throughout; striae traceable though they are not well-defined; two dorsal and the pre-apical pores present on each elytron; humeral group (pores 1–4) of marginal umbilicate series equidistantly spaced, middle group (pores 5 and 6) close to each other ( M. mahua n. sp.) or widely spaced ( M. heweii n. sp.); only protarsomeres 1 modified in male; ventrite VII with one pair of apical setae in male, while two pairs in female; male genitalia small and moderately sclerotized, nearly straight ( M. mahua n. sp.) or strongly sinuate ( M. heweii n. sp.), with apex bent ventrally.

Remarks. The bellowing characters are important for the identification of this new genus: mentum with base widely concave; submentum 8- to 9-setose; apical striole well-defined and more or less connected to stria 5; and protibia sulcate ( M. mahua n. sp.) or not ( M. heweii n. sp.).

Miaotrechus n. gen. is close to the genus Guizhaphaenops Vigna Taglianti, 1997 because both of them share the following characters: labial suture absent and only protarsomere 1 modified in male ( Vigna Taglianti 1997; Uéno 2000). However, Miaotrechus is an Anophthalmus-like (frontal furrows complete), whereas Guizhaphaenops a semi-aphaenopsian (frontal furrows obviously reduced). Pronotum is quadrate in Miaotrechus , instead of round or barrel-shaped in Guizhaphaenops . Right mandibular tooth is tridentate in Miaotrechus , but bidentate in Guizhaphaenops (except G. pouillyi Deuve et Quéinnec, 2014 which has a tridentate right mandible). Other differences of both genera are also indicated on elytral configurations including chaetotaxy and male genital structures.

Etymology. Generic name is derived from “ Miao -” (minority people living in Guizhou and other provinces of southern China) + “ trechus ”, to refer to the fact that beetles of this new genus are occurring in Miao’s territory.

Range. China ( Guizhou). Only two species known from two different caves of southern Guizhou Province ( Fig. 1 View FIG ).