Trechus validicollis, Sciaky et Pavesi, 1995

Belousov, I. A. & Kabak, I. I., 2021, Three new species of the genus Trechus Clairville, 1806 from Sichuan (Coleoptera: Carabidae: Trechini), Russian Entomological Journal 30 (4), pp. 401-421 : 407

The validicollis -species group

The group includes some species common in northern and central Sichuan. It can be characterized as follows: large-sized species, habitus robust and convex, color rufous to pitchy black, pronotum mostly with acute or rectangular hind angles and sides deeply sinuate before them, elytra broad ovate, with striae clearly impressed and roughly punctured. Preapical pore is mostly located closer to the elytral apex than level of anterior end of apical striole. The most important diagnostic feature of group members is the structure of the male genitalia: the median lobe large and thick, with apex curved upward; endophallus armature heavily sclerotized, consisting of several complexly twisted pieces.

The group is typical for Sichuan Province, only marginally penetrating to neighboring areas of Gansu Province (unpublished data).

Species are largely ripicolous and inhabit humid biotopes on banks of mountain streams. Despite their dark pigmentation, robust habitus and large size, members of this species group inhabit not only forests but also alpine meadows and often occur at very high elevations exceeding 4000 m.

The group is named after the first species described, Trechus validicollis Sciaky et Pavesi, 1995 from the mountains near Sanggarpar. The group encompasses six known taxa (including the new species described below): T. validicollis . T. validicollis yakoushanus Deuve, 2004 , T. altitudinum Deuve, 2004 , T. kurbatovi Belousov et Kabak, 2000 , T. trachypachys Sciaky et Pavesi, 1995 . The latter species is known only from female specimens [ Sciaky, Pavesi, 1995; Belousov, Kabak, 2000] and its assignment to this group needs further evidence.