Culicoides biting midges: Their role as arbovirus vectors

Culicoides biting midges are among the most abundant of haematophagous inse cts, and occur throughout most of the inhabited world. Across this broad ra nge they transmit a great number of assorted pathogens of human, and domest ic and wild animals, but it is as vectors of arboviruses, and particularly arboviruses of domestic livestock, that they achieve their prime importance . To date, more than 50 such viruses have been isolated from Culicoides spp . and some of these cause diseases of such international significance that they have been allocated Office International des Epizooties (OIE) List A s tatus. Culicoides are world players in the epidemiology of many important a rboviral diseases. In this context this paper deals with those aspects of m idge biology facilitating disease transmission, describes the factors contr olling insect-virus interactions at the individual insect and population le vel, and illustrates the far-reaching effects that certain components of cl imate have upon the midges and, hence, transmission potential.