Failure to propagate equine infectious anemia virus in mosquitoes and Culicoides variipennis

Laboratory-colonized mosquitoes, Culex tarsalis, aedes aegypti, Culiseta inornata, and Anopheles free-borni, and the biting gnat, Culicoides variipennis, were exposed to equine infectious anemia virus. Exposure to the virus was by intrathoracic inoculation for mosquitoes and by oral ingestion of an infective blood meal through a membrane for C variipennis. After various intervals, groups of 15 to 20 insects were homogenized and inoculated into susceptible ponies. Positive immunodiffusion test results were used as criterion for equine infectious anemia infection in ponies. Virus was not detected in the 4 species of mosquitoes at 3, 6, 12, and 18 days after inoculation, or in C variipennis at 6, 8, 12, 14, 21, and 26 days after oral exposure to the virus.