Effects of nonhost-plant odors on anemotactic response to host-plant odor in female cabbage root fly,Delia radicum, and carrot rust fly,Psila rosae.

An inflatable polythene wind tunnel was used for behavioral assays of femaleD. radicum andP. rosae in diffuse host- and non-host-plant odor, alone and in combination. Host-plant odor caused an upwind anemotactic response in both species. Changes in fly distribution, relative to wind direction, occurred when onion odor was combined with host odor forD. radicum andP. rosae, and when sage odor was combined with carrot ordor forP. rosae. The assay has potential for screening volatiles for their behavior-modifying effects.