Laboratory infections of Culicoides debilipalpis and C. stellifer (Diptera: Ceratopogonidae) with bluetongue virus.

Six species of field-collected Culicoides females were used in preliminary laboratory tests: C. biguttatus, C. debilipalpis, C. obsoletus, C. stellifer, C. variipennis and C. venustus. Tests were conducted to determine if females would take a blood meal through a membrane, if blood fed females could be maintained in the laboratory for up to 14 days and if they could support replication of bluetongue virus (BTV) serotype 11. One pool of C. stellifer (23 specimens) assayed positive for BTV 7 days following intrathoracic inoculation, which datum suggests that this species might be capable of harboring the virus. One of 52 individually assayed C. debilipalpis females in 2 trials was positive for BTV at 14 days after membrane feeding on a mixture of BTV and sheep blood (infection rate 1.9%), and 1 of 2 pools of C. debilipalpis (26 specimens) was positive 14 days after blood feeding. These data for C. debilipalpis showed that the species can pick up and harbor BTV through replication of the virus.