Uenotrechus Deuve et Tian, 1999

Wei, Guofu, Chen, Jujian & Tian, Mingyi, 2017, A review of the aphaenopsian ground beetle genus Uenotrechus Deuve et Tian, 1999 (Coleoptera: Carabidae: Trechinae), Zootaxa 4282 (2), pp. 361-373 : 362

Genus Uenotrechus Deuve et Tian, 1999

Deuve et al. 1999: 133

(Type species: Uenotrechus liboensis Deuve et Tian, 1999 )

Generic characteristics. Highly modified aphaenopsian trechines, large sized, eyeless, depigmented, body densely pubescent, fore body (head and thorax) as long as hind part (elytra). Head elongated, nearly parallel-sided (most species), or slightly expanded ( U. liboensis ), suddenly constricted posteriorly, forming a collar-shaped neck constriction, presence of two pairs of supraorbital setiferous pores, right mandibular teeth tridentate though more or less reduced in some individuals; ventral head as in Fig. 1 a, labial suture moderately defined, mentum 4-setose (but 6-setose in U. gejianbangi sp. n.), mentum tooth short and widened, bifid ( U. liboensis and U. nandanensis ) or simple ( U. gejianbangi sp. n. and U. deuvei sp. n.) at tip; both maxillary and labial penultimate palps much longer than the apical ones respectively, the 2nd labial palps unisetose on inner margin, instead of two in most trechines; antennae thin and elongated, extending at most to apical 1/6 of elytra. Prothorax dolioform, propleura distinctly tumid at basal half, evidently visible from above; pronotum barrel-shaped, distinctly elongated, base as wide as or slightly wider than front; a pair of lateromarginal setae present at about apical 1/4. Elytra oblong-ovate, nearly twice as long as wide, shoulders lacking, prehumeral part long and sinuate, side margins finely bordered, subserrulate and ciliated throughout; striae disappeared; chaetotaxal pattern ( Fig. 1 b): presence of two dorsal and the preapical setiferous pores, the 1st pore in the humeral group of the marginal umbilicate series inwardly and backwardly shifted, the 5th and 6th pores in the middle group widely spaced. Protibia smooth, without longitudinal sulcus; protarsi not modified in male. Abdominal ventrite VII 4 -setose apically in both sexes. Male genitalia weakly, moderately or strongly sclerotized, very thin and elongated ( U. liboensis and U. nandanensis ) or very short and stout ( U. gejianbangi sp. n. and U. deuvei sp. n.), apical lobe distinctly reflexed ( U. liboensis and U. nandanensis ) or hooked ventrally ( U. gejianbangi sp. n. and U. deuvei sp. n.) in lateral view; sagittal aileron present ( U. liboensis and U. nandanensis ) or not ( U. gejianbangi sp. n. and U. deuvei sp. n.); parameres well developed, each with three or four long setae at apical portion.

Range. China (Guizhou and Guangxi) ( Fig. 2 ).

There are four species in this genus which can be divided into two species groups according to the mentum tooth and especially male genitalic structure, i.e. the northern congeners ( U. liboensis and U. nandanensis ) which have a bifid mentum tooth and a long and slenderer median lobe with a well-developed sagittal aileron (Fig. 5), while the southern congeners ( U. gejianbangi sp. n. and U. deuvei sp. n.) have a simple mentum tooth, and a short and stout median lobe without sagittal aileron ( Fig. 7 ).

Figures

FIGURE 1. Uenotrechus gejianbangi Tian et Wei, sp. n., male, paratype. a head, ventral view b elytra, chaetotaxy indicated by white points.

FIGURE 2. Distribution of the genus Uenotrechus. circles U. liboensis Deuve et Tian (a Cave Jinshi Dong b Cave Gui Dong II c Cave Chang Dong); square U. nandanensis Deuve et Tian; star U. gejianbangi Tian et Wei, sp. n.; triangle U. deuvei Tian et Chen, sp. n.

FIGURE 7. Male genitalia of Uenotrechus species, median lobe (lateral view) and apical lobe (dorsal view). a and b U. gejianbangi Tian et Chen, sp. n. (Cave Ji Dong); c and d U. deuvei Tian et Wei, sp. n. (Cave Longmu Dong I).