A contribution to cavernicolous beetle diversity of South China Karst: eight new genera and fourteen new species (Coleoptera: Carabidae: Trechini) Author Tian, Mingyi 0000-0003-2823-7619 mytian@scau.edu.cn Author Huang, Sunbin 0000-0001-8357-6651 Author Jia, Xinyang 0000-0003-1936-5926 527748207@qq.com text Zootaxa 2023 2023-02-15 5243 1 1 66 http://dx.doi.org/10.11646/zootaxa.5243.1.1 journal article 54139 10.11646/zootaxa.5243.1.1 1476f0e1-3886-401f-bf56-c294a0a99962 1175-5326 7642400 Ecotrechus n. gen. Type species: Ecotrechus ruruiae n. sp. ( Laba Dong , Ziyun , Guizhou ) Generic characteristics. Medium-sized for cave trechines, anophthalmic though head with uncompleted frontal furrows; body stout, brown, elytra much longer than fore body including mandibles; surface smooth and glabrous. Head elongate, much longer than wide, nearly parallel-sided; neck narrow, constriction well-marked; absence of supraorbital setiferous pores; frontal furrows parallel-sided in most part, divergent and superficial posteriorly; frons slightly but vertex strongly convex; right mandibular tooth bidentate; labium completely fused; mentum bisetose, tooth short, and bifid at tip, base largely concaved; submentum 8 or 9-setose; antennae rather short, extending at about 3/5 of elytra from base, scape slightly widened, shorter than pedicel. Propleura invisible from above; pronotum almost rounded, widest at about middle; lateral margins narrowly and evenly reflexed in most part, wider before hind angles, without latero-marginal setae; both fore and hind angles rounded; base slightly narrower than front, both unbordered; disc moderately convex, both anterior and posterior transversal impressions superficial, median line well marked; basal foveae small and shallow. Elytra ovate, strongly convex; humeral angles widely rounded, whereafter slightly contracted and sinuate; lateral margins finely beaded, smooth but sub-serrate and ciliate from humeral angle and ended before the widest point; widest at about middle; surface depressed near base; striae deep, comprised of large, isolated punctures; intervals convex; absence of dorsal and preapical pores; the marginal umbilicate pores not aggregated, only the 2 nd pore close to marginal gutter, 4 th distant from 3 rd ; the 5 th and 6 th pores closed to each other. Legs moderate elongate for cave trechines; protibiae longitudinally sulcated. Ventrites IV– VI each with two pairs of paramedian setae, ventrite VII quadrisetose in female. Remarks. Ecotrechus n. gen. is a peculiar genus with no evident relative within Chinese cave trechines. Lack of supraorbital setiferous pore on head, absence of latero-marginal setae on pronotum and of dorsal and preapical pores on elytra are the striking unique generic characters of this new genus. At the first sight, Ecotrechus n. gen. is more or less similar to Libotrechus Uéno, 1998 , which is ranging from southern Guizhou (Libo County), through northern (Huanjiang Maonan Autonomous County) to central (Du’an Yao Autonomous County) Guangxi ( Uéno & Ran 1998 , Lin & Tian 2014 ), in body shape in particular the pronotum. However, it is very different from Libotrechus in many aspects, for example: (1) head more elongated in Ecotrechus n. gen. , whereas stouter in Libotrechus ; (2) labium completely fused in Ecotrechus n. gen. , vs. mentum and submentum well separated by a clear labial suture in Libotrechus ; (3) scape of antennae shorter than pedicel in Ecotrechus n. gen. , vs. subequal in Libotrechus ; (4) pronotum almost rounded in Ecotrechus n. gen. , vs. subcordate in Libotrechus . Etymology. “Ec-” + trechus . “Ec” is abbreviated for Explore China , an active caving team in China . Gender masculine. Range. China ( Guizhou ) ( Figure 1f ).