COMPARISON OF BAIT CATTLE AND CARBON DIOXIDE-BAITED SUCTION TRAPS FORCOLLECTING CULICOIDES-VARIIPENNIS SONORENSIS (DIPTERA, CERATOPOGONIDAE) AND CULEX-QUINQUEFASCIATUS (DIPTERA, CULICIDAE)

Carbon dioxide-baited suction trap collections were related to simulta neous bait cattle collections of Culicoides variipennis sonorensis Wir th & Jones. Trap collections varied directly with numbers taken from e ach of 3 calves. More (3.4x) C. v. sonorensis were taken in a trap wit h 1,000 ml CO2/min versus a trap baited with approximate to 300 ml/min (matched to calves by weight). Numbers of insects taken from three in dividual calves relative to their equivalent CO2 output did not differ , but engorgement of C. v. sonorensis was higher on 1 calf compared wi th the other 2 calves. Up to 281 C. v. sonorensis fed on a calf expose d for 10 min. More male (7.7x) and female (6.1x) C. v. sonorensis were collected from the calf relative to its equivalent amount of CO2. Und er conditions described here, female C. v. sonorensis caught by a suct ion trap multiplied by 7.2 approximates numbers expected to be caught near a calf. Engorgement of C. v. sonorensis on individual calves decl ined as abundance increased. Culex quinquefasciatus Say was collected in equal numbers from the calves and their equivalent CO2 output, and none fed on the cattle. Most (85%) C. v. sonorensis in the vicinity of the CO2-baited suction trap were collected in the catch bag, compared with 26% of Cx. quinquefasciatus.