Learning of host-infested plant volatiles in the larval parasitoid Cotesiakariyai

The ability to learn plant volatiles in Cotesia kariyai females was examine d by wind tunnel bioassays. Searching experience on a host-infested corn pl ant increased subsequent flight responses of females to the infested plant. Females experiencing host by-products together with the volatiles extracte d from infested leaves one time showed an increased response. However, such behavioral changes were not observed in females which experienced only the host by-products or the volatiles. Thus, the increased response is conside red to be preference learning. Multiple experiences of C. kariyai with host by-products together with the volatiles did not increase their flight resp onse to the volatiles. Furthermore, this learned response gradually decreas ed within 2 days. These behavioral modifications based on experience would be advantageous for C. kariyai to locate their polyphagous hosts efficientl y.