Seasonal fluctuations of Culicoides species (Diptera: Ceratopogonidae) in Kenya

Abstract

AbstractLight-traps were used to collect adult Culicoides from 61 sites throughout Kenya and to sample long-term population fluctuations at six sites. Activity patterns were recorded with a suction trap and larval habitats were sampled with laboratory emergence traps. Culicoides cornutus De Medllon, C. milnei Aust., C. pallidipennis C, I. & M., C. schultzei (End.) gp. and C. zuluensis De Meillon were found widespread and also concentrated at livestock pens. Their seasonal population fluctuations did not correlate clearly with rainfall but all these species persist throughout the year. The activity of C. pallidipennis and C. schultzei gp. extends over the whole night and is inhibited by winds in excess of 3 m/s and stimulated by high temperatures and relative humidity. Larval habitats were mainly in mud mixed with detritus or dung; larvae of C. pallidipennis and C. schultzei gp. were both found in swamp mud but not in dung pats. The significance of these findings is discussed in relation to the epidemiology of bluetongue virus disease of sheep and ephemeral fever virus disease of cattle.