The seasonal and geographical distribution of Culicoides imicola, C. pulicaris group and C. obsoletus group biting midges in central and southern Spain

Abstract

Pirbright-type light traps were used to collect Culicoides biting midges (Diptera: Ceratopogonidae) at fifteen sites in twelve provinces of central Spain and Andalusia. A total of 293,625 Culicoides were collected in 1,387 samples over a two year period. These comprised approximately 9.2% Culicoides imicola, 11.4% C. pulicaris group, 1.6% C. obsoletus group and 12.2% C. circumscriptus. Culicoides imicola was present at ten of the fifteen sites; the five sites from which it was absent were the most eastern of the fifteen. The greatest abundance of this species was at Navalmoral in Caceres Province. Culicoides pulicaris group were present at all sites; C. obsoletus group were present at twelve sites. The annual peaks in abundance were: C. imicola, August-October; C. pulicaris group, May-June; and C. obsoletus group, March-June. The geographical and seasonal distributions of C. imicola are consistent with those of the outbreaks of African horse sickness (AHS) and bluetongue (BT) during epizootics in Spain, and support the contention that C. imicola was the major vector of AHS and BT viruses.