EVALUATION OF OLFACTORY RESPONSES BY GONATOCERUS ASHMEADI, A PARASITOID OF GLASSY-WINGED SHARPSHOOTER EGG MASSES ON VARIOUS HOST PLANTS

• Author(s): Coviella, Carlos; Luck, Robert; Morgan, David;
• Abstract: This proposal seeks to improve the use of Gonatocerus spp. (Hymenoptera: Mymaridae) i.e., egg parasitoids, in urban and riparian habitats where it is a politically accepted tactic for suppressing glassy-winged sharpshooter, Homalodisca coagulata (Say) (Homoptera: Cicadellidae) (GWSS). Such releases are part of an area wide pest management strategy for suppression of GWSS. This proposal has two general objectives: 1) to determine the relative importance of volatile cues (host plant versus host egg-mass) for Gonatocerus spp. to locate and parasitize GWSS egg masses, and 2) to determine whether Gonatocerus spp released in an urban or riparian environment is equally successful in locating egg-masses in the variety of host plants utilized by GWSS as oviposition sites in these habitats. To fulfill these objectives, olfactometer techniques will be used to study the long-range host location behavior of G. ashmeadi to determine whether it a) is innately attracted via chemical cues to GWSS egg masses, b) learns these cues after attacking an egg mass in a particular host plant species or emerging from an egg-mass in a particular host plant species, or c) gains experience by attacking an egg-mass located in a particular host plant species that modifies its innate host location behavior for egg masses laid in other host plant species. Host location-host selection information will identify host plant species with GWSS egg-masses preferred by Gonatocerus spp for parasitization and identify those that are not recognized or readily recognized by these parasitoids. These results will then be used to compare the host finding behavior of the other Gonatocerus spp.
• Publication Date: Aug 2003
• Journal: 2003 Pierce's Disease Research Symposium