Bionomics of livestock-associated Culicoides (biting midge) bluetongue virus vectors under laboratory conditions

Females of several species of Culicoides Latreille (Diptera: Ceratopogonidae) can transmit arboviruses of veterinary importance, for example bluetongue virus. The basic bionomics of the major bluetongue virus vector species remains unknown. This study reports on the bionomics of livestock-associated vector Culicoides species under laboratory conditions. Insects were collected from the field from spring to autumn 2014 on a cattle farm in Spain. Eggs obtained from gravid females were maintained for larval rearing and pupal development. Culicoides imicola Kieffer took the longest time to oviposit; the highest number of eggs was laid by Culicoides circumscriptus Kieffer (148.7 +/- 73.8 eggs). Field-collected gravid C. imicola and Obsoletus complex females showed the longest lifespans. The longest lifecycle, generally more than 40 days, was recorded for Culicoides cataneii Clastrier. Culicoides paolae Boorman and C. circumscriptus seemed to be the most suitable for laboratory rearing in view of their high oviposition rates, short lifecycles, long adult lifespans and female-biased sex ratios. Vector species such as Culicoides obsoletus (Meigen) appeared difficult to maintain in colonies in the laboratory. This research contributes to knowledge of the basic bionomic parameters of vector and non-vector Culicoides species, highlighting the complexities involved in the establishment of sustainable laboratory colonies of field-collected Culicoides species.