Callicerus obscurus Gravenhorst, 1802

Brunke, Adam J., Klimaszewski, Jan, Dorval, Julie-Anne, Bourdon, Caroline, Paiero, Steven M. & Marshall, Stephen A., 2012, New species and distributional records of Aleocharinae (Coleoptera, Staphylinidae) from Ontario, Canada, with a checklist of recorded species, ZooKeys 186, pp. 119-206 : 148-149

Callicerus obscurus Gravenhorst, 1802 New Canadian Record Figs 64142-143Map 64

Material examined.

CANADA: ON:Hamilton Div., Hamilton, 15.v.1985, M. Sanborne, 1 (CNC); Huron Co., Brucefield, hedgerow, pitfall, 11.v.2009, A. Brunke, 1 (DEBU), same data except: 22.vi.2009, 1 (DEBU), Auburn, hedgerow, pitfall, 11.v.2010, A. Brunke, 1 (DEBU).

Distribution.

Canada: ON; western Palaearctic ( Assing 2001; Gusarov 2003b). Adventive in Canada.

Comments.

Callicerus obscurus is recorded from Canada for the first time based on Ontario specimens mostly collected in agricultural hedgerows. Gusarov (2003b) first reported this species from North America in an online catalog of North American Athetini based on specimens collected in Ontario (V. Gusarov, pers. comm). The ' undescribed Callicerus s.str.' from Ontario groundhog burrows mentioned by Ashe (in Newton et al. 2000) may in fact be this adventive species. Therefore, all Callicerus in North America may be introduced. Males of Callicerus obscurus are easily recognized by their extremely elongate antennomere 10. In North America, Callicerus obscurus may be separated externally from Callicerus rigidicornis by the more elongate pronotum (Fig. 64).

Callicerus obscurus inhabits open and forested habitats in its native range and was suggested to be largely subterranean by Assing (2001) based on highly seasonal (mostly spring) surface activity and the low numbers of individuals captured in each collection event.