Effects of temperature on virogenesis of bluetongue virus serotype 11 in Culicoides variipennis sonorensis

.Culicoides variipennis sonorensis females were fed bluetongue virus serotype 11 mixed in sheep blood and were held at constant temperatures of 32, 27, 21 and 15 o C. Virogenesis, as measured by enzyme‐linked immunosorbent assay (ELISA), proceeded significantly faster at higher temperatures. Based on ELISA absorbance ≥0.2, some flies first were categorized as infected after 1 day, 2 days and 4 days at 32, 27 and 21 o C, respectively. Peak levels of virus antigen were seen after 5–7, 7–13 and 18–22 days for flies held at 32, 27 and 21 o C, respectively. There was no significant virus replication in flies held at 15 o C for 22 days, but latent virus replicated and was detected easily (44% infection) 4–10 days after these flies were transferred to 27 o C. The implications for temperature effects on bluetongue epizootiology are discussed.