Abundance and Species Composition of <I>Culicoides</I> (Diptera: Ceratopogonidae) at Cattle Facilities in Southern Alberta, Canada

Abstract

Culicoides fauna was examined at seven feedlots and one rangeland site (Warner) in southern Alberta, Canada, during a 3-yr period. Eight species and species groups accounted for > 99% of the Culicoides (Diptera: Ceratopogonidae) captured. The most abundant species or groups were Culicoides gigas Root and Hoffman, Culicoides sonorensis (Wirth and Jones), Culicoides (Selfia) group, and Culicoides palmerae group. These accounted for 78-88% of the Culicoides captured, with the balance being members of the Culicoides cockerellii section, Culicoides crepuscularis Malloch, Culicoides wisconsinensis Jones, and Culicoides yukonensis Hoffman. Univariate and multivariate analyses indicated that the rangeland site was characterized by greater abundance of C. sonorensis and C. palmerae and lower abundance of C. (Selfia) compared with the feedlot sites. The Culicoides fauna was more dissimilar among sites as geographic distance between sites increased. Species of Culicoides captured in this study showed three broad patterns of seasonal abundance. The C. palmerae group had the earliest seasonal activity, with an increase in June, peak in July, and greatly reduced abundance thereafter. C. crepuscularis, C. (Selfia), C. wisconsinensis, and C. gigas had later periods of activity, with peak abundance in July, but moderate abundance in June and August. C. cockerellii, C. yukonensis, and C. sonorensis had the latest periods of activity, with populations increasing through June and July, peaking in August, and declining thereafter. C. sonorensis was somewhat unique on that it was the only species with moderate abundance as late as September.