Trichotichnus, Morawitz, 1863

Kataev, Boris M., Hongbin, Liang & Wrase, David W., 2022, New data on carabid beetles of Trichotichnus s. str. (Coleoptera: Carabidae) of Yunnan (China) and adjacent areas, with description of six new species and two new subspecies, Zootaxa 5159 (3), pp. 301-353 : 303

Subgenus Trichotichnus s. str.

Diagnosis [slightly modified from Kataev (2020)]. Fronto-ocular furrows shallow, at most deepened only at clypeus, reaching or not reaching supraorbital furrows. Fronto-clypeal suture superficial or slightly deepened. Genae narrow to moderately wide. Ligular sclerite widened at apex or almost parallel-sided. Paraglossa narrow, separated from ligular sclerite by wide (about as wide as paraglossa apically) notch. Elytra with lateral groove flat throughout, without distinct elongate convexity along this groove apically. Elytral marginal umbilicate series more or less continuous or with a short gap at middle. Metepisternum markedly narrowed posteriorly, its anterior margin not longer than inner margin. Last abdominal sternite (VII) of male with one or two pairs of marginal setigerous pores. Gonocoxite with one short seta (occasionally with two setae) on ventral outer edge or on both ventral and dorsal outer edges at their middle or in their basal portion. Median lobe of aedeagus with apical orifice in dorsal position or slightly shifted to left; apical capitulum absent or small, in many species prominent only dorsally.

Remarks. Habu (1961, 1973, 1980) arranged the species of Trichotichnus s. str. from Japan and Taiwan in four species groups: the congruus, longitarsis, wansuiensis and leptopus groups, but their diagnostic characteristics, particularly the number of setae on the abdominal sternite VII of male and the presence of longitudinal sulcus on the dorsal side of the protibia, are variable among closely related species from mainland China, and at least the Chinese species with reduced wings, which should formally be included in the leptopus or wansuiensis groups, most likely arose independently from different ancestors that had fully developed wings. The problem of the arrangement of Chinese species in species groups, though of great importance, is largely beyond the scope of the present study, since it cannot be solved based on this material. The true relationships between species of Trichotichnus require special integrative studies, including molecular analysis, which are possible only based on a comparative revision of most of the described species from all regions.