Patterns of flight activity of Culicoides variipennis (Coquillett) (Diptera: Ceratopogonidae).

Abstract

The flight activity of Culicoides variipennis (Coquillett), as shown by truck-trap collections, was greater near dusk and dawn and during moonlight hours than in darker periods of the night. Peaks of activity near dusk were larger than those near dawn and began earlier in the fall, relative to sunset, than in the summer. The evening peaks also began at higher light intensities in the fall, which was characterized by relatively low temperatures and evaporation rates. Biting activity, indicated by CO2-trap collections, usually was greatest in a 2-hr period at sunset. However, patterns of biting and flight activity did not always closely coincide. Culicoides haematopotus Malloch and Culicoides posoensis Wirth & Blanton also had peaks of flight activity near dusk and dawn, and Culicoides crepuscularis Malloch and Culicoides freeborni Wirth & Blanton had them near dusk. All species collected were active throughout the night.