The responses of male and femaleMicroplitis croceipes(Cresson) (Hymenoptera: Braconidae) to volatiles fromHeliothis zea(Boddie)(Lepidoptera: Noctuidae) larvae feeding on cowpeas were examined in a flight tunnel. The flight response of ovipositionally experienced female parasitoids to individual components and the removal of individual components (i.e., larvae, leaves, and feces) from the plant-host complex was examined. The flight response to control odors, larval feeding damage, and artificial leaf damage also was studied. Larval feces was the most important component of the plant-host complex in the initiation of flight, oriented flight, and landing on the odor source. Artificial leaf damage had an inhibitory effect on these behaviors. There was no treatment effect on flight durations.