Collection size of 3 species of mosquitoes (Aedes taeniorhynchus, Anopheles atropos, and Culex nigripalpus) and a species of biting midge (Culicoides furens) in CDC-type traps baited with carbon dioxide and octenol were significantly increased with the addition of heat. The presence of heat also significantly reduced collection size of the tabanid Diachlorus ferrugatus.