Miaotrechus, Tian & Chen & Ma, 2020

Tian, Mingyi, Chen, Mengzhen & Ma, Zijun, 2020, A new anophthalmic trechine genus and two new species from southern Guizhou China (Coleoptera: Carabidae: Trechini), Zootaxa 4766 (4), pp. 575-587 : 576

Miaotrechus n. gen.

Type species. Miaotrechus mahua 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 ).

Figures

FIG. 1 Distribution of the genus Miaotrechus n. gen.