EXPERIMENTAL-INFECTION OF CULICOIDES LAHILLEI (DIPTERA, CERATOPOGONIDAE) WITH EPIZOOTIC HEMORRHAGIC-DISEASE VIRUS SEROTYPE-2 (ORBIVIRUS, REOVIRIDAE)

To evaluate the vector competence of Culicoides lahillei Lutz for epiz ootic hemorrhagic disease (EHD) viruses, wild-caught females were allo wed to feed on 4 viremic white-tailed deer, Odocoileus virginianus Zim mermann, experimentally infected with EHD virus serotype 2 (EHDV-2). C olonized C. variipennis sonorensis (Coquillett) were included as a pos itive control. Virus was not isolated from 13 C. lahillei tested 4-15 d after feeding on deer with viremias of 3.0 or < 2.1 log(10) tissue c ulture infectious dose(50) (TCID50) virus per milliliter of blood. Vir us was isolated from 6 of 69 (8.7%) C. lahillei tested 4-15 d after fe eding on deer with viremias of 5.3 or 6.0 TCID50 virus per milliliter of blood. The average amount of EHDV-S ingested in the blood meal rang ed from < log(10) 1.5 to log(10) 1.9 TCID50 per C. lahillei. Titers of EHDV-2 in C. lahillei that tested positive 4-15 d after feeding peake d at log(10) 2.7 TCID50 EHDV per fly. Replication of EHDV-2 also occur red in control C. varipennis. This report of infection of C. lahillei with an EHD virus serotype indicates that C. lahillei may be a vector of EHD viruses.