The four-armed olfactometer was used to measure the olfactory response of Trichogrammatoidea bactrae Nagaraja,Trichogramma confusum Viggiani,T.raoi Nagaraja and T.closlerae Pang et Chen to the volatiles derived from eggs,hexane extract of egg surface and ventral squama of Corcyra cephalomica(Stainton) in laboratory.The results showed that adults of these four species of trichogrammatid prolonged their retention time in the treated areas,and indicated the kairomones from C.cephalomica could stimulate an intensive search behavior of adults.