Orbiviruses from Culicoides in Florida

Between 1980 and 1983, 45,484 Culicoides spp. collected in Florida near cattle have been examined for orbiviruses by attempted isolation in cell cultures and intravenous (IV) inoculations of embryonated chicken eggs. Bluetongue virus (BTV) serotype 2 was isolated from a pool of Culicoides insignis trapped at Ona. This is the 1st recovery of BTV from this species representing the 2nd new world species of Culicoides from which BT viruses have been isolated. C. insignis is a neotropical form which extends from northern Florida through the Caribbean region and much of South America. If this species is proven capable of biological transmission of BTV, it could help explain the distribution of antibodies to BTV in areas lacking C. variipennis. Epizootic hemorrhagic disease virus (EHDV) serotype 2 was recovered from several pools of C. variipennis collected at 2 beef cattle operations in Florida. No viruses were isolated from the small number of C. arboricola, C. stellifer and C. niger examined.