none Cotesia glomerata; CHEMORECEPTION-; FOOD-PLANTS; Brassica oleracea gemmifera (cabbage); FOOD-RECOGNITION; Olfactory preferences to plant volatiles in flight tunnel Olfactory preferences in the host location process of the braconid wasp Cotesia glomerata (L.) (Hym., Braconidae) were investigated by observing the orientation behavior of individual females to various host-habitat related odor cues in a flight tunnel. Responsive wasps showed positive anemotaxis after release into the odor plume. Dual odor-choice tests revealed that wasps can discriminate between cabbage leaves infested by larval Pieris brassicae (L.) (Lep., Pieridae) and uninfested leaves. Infested plants were a preferred source of volatiles attracting the wasps. Feces and host larvae, two major components of a plant-host complex, were less attractive. Wasps probably respond to host-induced synomones, because host-infested leaves were more attractive than mechanically damaged cabbage leaves. Furthermore, the odor from the latter was preferred over that from damaged nonhost plants (tomato), indicating a response the host-plant specific synomones. The flight behavior and responsiveness of the wasps are discussed in relation to the different odor stimuli.