It’s been a long time since my last update on the beetles that I collected during my Great Basin Collecting Trip last August. GBCT Beetle #6 is the longhorned beetle, Crossidius ater (family Cerambycidae). This species is easily distinguished from other species in the genus by its completely black coloration. Moreover, unlike most other species in the genus it shows almost no geographic variation despite being rather widely distributed across the mountainous west. This, compared to the two other species that we were targeting for the trip—C. coralinus and C. hirtipes, each having been classified into numerous, often highly geographically restricted subspecies across the almost equally wide distributions of their parent species. Crossidius ater also differs from these latter two species in its less specific host plant preferences. While adults of C. coralinus and C. hirtipes greatly favor flowers of Ericameria nauseosa and Chrysothamnus viscidiflorus, respectively (Linsely & Chemsak 1961), adults of C. ater can be found on flowers of both of these species as well as those of Haplopappus bloomeri, H. suffruticosa (Linsley & Chemsak 1961) and Guterrizia sarothrae (Barr & Penrose 1969). The latter authors also reported larvae and a teneral adult taken in the roots of Artemisia tridentata.
The adult in the above photograph was one of several collected on flowers of E. nauseosa growing on the eastern slope of the Sierra Nevada in Mono Co., California.
Barr, W. F. & R. L. Penrose. 1969. Notes on the distribution and bionomics of some Idaho Cerambycidae (Coleoptera). The Great Basin Naturalist 29(2):88–95 [pdf].
Linsley, E. G. & J. A. Chemsak. 1961. A distributional and taxonomic study of the genus Crossidius (Coleoptera, Cerambycidae). Miscellaneous Publications of the Entomological Society of America 3(2):25–64 + 3 color plates.
Copyright © Ted C. MacRae 2014