In comparative studies, a spherical black decoy and a doughnut-shaped black decoy were generally equally attractive to Tabanids when used as baits in Malaise traps. Three of ten species did not respond to either decoy. The combination of CO2 and a black decoy did not increase collection numbers over those collected with CO2 alone. This would indicate that the two types of attractants, the black object and the CO2 are sampling the same population.