Trechus kashensis, Belousov & Kabak, 2001

Belousov, Igor A. & Kabak, Ilya I., 2019, New species of the genus Trechus Clairville, 1806 from the Chinese Tien Shan (Coleoptera: Carabidae), Zootaxa 4679 (1), pp. 47-68 : 55-56

The kashensis species group

This group currently includes two closely related species, one of which is described below. The species of the group may be characterized as follows: small size, body convex and broadly ovate, appendages rather short and thick, color of the upper-side dark brownish, eyes medium-sized and flat, tempora flat, with distinct, though short and moderately dense pubescence; pronotum markedly transverse, with sides barely sinuate or not sinuate before hind angles, the latter obtusangular, basal margin more or less salient medially, emarginate and obliquely truncate laterally; prebasal transverse impression rather sharply engraved, gradually arcuate; basal foveae small and shallow; basal surface of pronotum longitudinally rugulose, median line deeply impressed near pronotal base; elytra short ovate, convex, with salient humeri and elytral apices commonly rounded; striation rather shallow, though striae 1–3 distinct and continuous; intervals 1–2 subconvex, others flat; preapical pore located close to the apex of elytra, approximately at level of umbilicate pore 8; front tibiae depressed on exterior surface, with only a few, distinct hairs on their anterior surface near apex; aedeagus small, thick, its apex clearly attenuate downward; endophallus armature consisting of pieces heavily sclerotized and complexly twisted, and of a large scaly patch near left wall of aedeagus; parameres short, rather thick, left one longer, with a developed ventral apophysis, each paramere bearing 4 apical setae.

Among the Trechus species of Central Asia, this group seems to be highly isolated in having a short ovate habitus, pronotum with prebasal transverse impression evenly arcuate and sharply engraved; small subcylindrical aedeagus with endophallus armature consisting of heavily sclerotized pieces and large scaly patch near its left wall. In their external morphology and genitalia characters, the species of the group appear to be most similar to some Siberian members of the genus, such as: T. bakurovi Shilenkov, 1984 , T. montanus Motschulsky, 1844 and species of the stipraisi group ( Belousov & Kabak 1992).

The distributional range of the group resembles that of the uygur species group except that it does not extend so far eastward ( Fig. 22 ).

The two known species of the group are similar in their biotope preferences. They mostly occur in the forest zone at middle elevations between 1700 and 2600 m, although some specimens were found in the alpine zone at elevations exceeding 3000 m.

Figures

FIGURE 22. Collecting sites of Trechus species of the kashensis group. Red square—T. kashensis Belousov & Kabak, 2001; yellow square—T. saluki sp. n. Localities’ numbers—as in the “Material” section.