none Busseola fusca; Chilo; Sesamia calamistis; FOOD-PLANTS; Pennisetum, Sorghum & Zea; Location by hymenopteran parasite using host & food plant infochemicals; CHEMICAL-SIGNALS; Infochemicals, use in location by hymenopteran parasite; HYMENOPTERAN-PARASITES; Cotesia flavipes & C. sesamiae; Host & host food plant location using volatile infochemicals Chilo orichalcociliellus; Chilo partellus; HYMENOPTERAN-PARASITES; Cotesia flavipes & C. sesamiae; Host & host food plant location using volatile infochemicals Cotesia flavipes; Cotesia sesamiae; CHEMORECEPTION-; Volatile infochemicals, use to locate lepidopteran host & host food plant; LEPIDOPTERAN-HOSTS; Busseola, Chilo & Sesamia; Host & host food plant location using volatile infochemicals Female Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) were attracted to odors in a Y-tube olfactometer from uninfested maize (Zea mays L.), sorghum (Sorghum bicolor (L.)), and napier grass (Pennisetum purpureum Schumach). In dual choice tests, Cotesia flavipes showed a preference for maize over sorghum, while maize and napier grass were equally attractive. In contrast, Cotesia sesamiae preferred volatiles from sorghum and napier grass over those from maize. The two parasitoids were significantly more attracted to maize infested with the stemborers, Chilo partellus (Swinhoe), Chilo orichalcociliellus Strand, Sesamia calamistis Hampson, and Busseola fusca (Fuller), than uninfested maize. In dual choice tests, Cotesia flavipes and Cotesia sesamiae were unable to discriminate between odors from plants infested by the different species of stemborers.