Observations on larval habitats of suspected Culicoides vectors of bluetongue virus in Florida.

Potential breeding sites for Culicoides variipennis (Coquillett) and C. insignis Lutz, suspected vectors of bluetongue virus (BTV) in Florida, were examined at 7 livestock facilities located in different geographic regions of the state. The 2 most productive habitats were mud contaminated by effluent from milking parlors (92.3 larvae/sample) and margins of vegetated ponds (18.8 larvae/sample). Four species of biting midges, C. crepuscularis Malloch, C. haematopotus Malloch, C. insignis, and C. variipennis were reared from immature stages extracted from substrate samples. Culicoides insignis was recovered from samples taken from muddy areas in pastures and margins of vegetated ponds, whereas C. variipennis was collected around waste lagoons and from mud contaminated by effluent from milking parlors.