A first estimation of Culicoides imicola and Culicoides obsoletus/Culicoides scoticus seasonality and abundance in Europe

Abstract

Culicoides imicola and C. obsoletus/C. scoticus are considered important vectors in Europe for the transmission of bluetongue and Schmallenberg virus. The seasonality and abundance of C. imicola and C. obsoletus/C. scoticus was assessed in Europe based on literature, expert input and modelling techniques detecting the onset and end of the vector season. Culicoides obsoletus/C. scoticus has a large distribution across Europe and can often be found in high abundances. The abundance peak is driven by temperature and humidity and is reached late spring/early summer and fall. The species is sometimes found as adult overwintering in stables but numbers are rather low; this can however have implications for the overwintering of the bluetongue virus. Culicoides imicola is restricted to countries around the Mediterranean basin and the predicted abundance is lower and the species appears only later in spring with a peak in fall.