Gonatocerus ashmeadi is an egg parasitoid that exhibit high potential for managing populations of glassy-winged sharpshooter, Homalodisca coagulata, in California. Homalodisca coagulata adults have different ovipositional and feeding preferences for host plants during the year. One important question to answer about these natural enemies is how do they locate H. coagulata egg masses among the various host plants of H. coagulata? We tested the hypothesis that G. ashmeadi may use chemical cues originating from the host plants themselves, host egg masses, or from interactions between the egg mass and the plant tissue as host location cues. To determine parasitoid preferences for test plant volatiles, plants were offered to individual parasitoids using a glass Y-tube olfactometer. Females were observed for 5 min. We collected data on the wasp time spent in each arm, number of visits per arm, and searching or stationary behaviors. In choice tests, female wasps preferred plants over absence of a plant (blank test). When exposed to a plant with H. coagulata egg masses versus a plant without egg masses, females visited and spent more time searching on the side hosting egg masses. These results suggest that chemical volatiles emanating from the plant-host complex are involved in the host location process of G. ashmeadi. The olfactory responses of female wasps to citrus, grapevines, red-tip photinia, and crape myrtle plants infested with H. coagulata egg masses will be discussed.