SHARPSHOOTER FEEDING BEHAVIOR IN RELATION TO TRANSMISSION OF PIERCE'S DISEASE BACTERIUM

• Author(s): Backus, Elaine; Purcell, Alexander; Walker, Andrew;
• Abstract: The establishment in California of the non-native glassy-winged sharpshooter (GWSS), Homalodisca coagulata, a vector of Pierces disease (PD) bacterium, Xylella fastidiosa, has transformed the previously low-level problem of PD into a potential disaster for California agriculture. Almost nothing is known of the exact feeding behaviors of GWSS and how they interact with the behavior of X. fastidiosa, (within the sharpshooters foregut) to facilitate transmission to grapevine. The Backus project will combine all three of the most important and successful methods of studying leafhopper-feeding behavior (i.e. histology of fed-upon plant tissues, videotaping of feeding on transparent diets, and electro-penetration graph [EPG] monitoring) to definitively identify all details of feeding. Both AC and DC EPG monitoring will be performed. All recorded waveforms will be thoroughly correlated with stylet activities, cell types within the host plant in which activities occur, and presence or movement of X. fastidiosa in and out of the stylets. Thus, our research also will provide crucial baseline information for the present projects of collaborators. Understanding the role of feeding behavior in the mechanism and efficiency of X. fastidiosa transmission will allow the development of a rapid, EPG-based screening tool for behaviors associated with inoculation (an inoculation-behavior detection method). Such a tool would have a direct impact on the grape industry by making many future, applied studies possible. For example, the detection method could be used to screen for differences in vector feeding or inoculation behavior among grape varieties, or formulations of artificial diet, or between infected vs. uninfected plants, or infective vs. uninfective vectors.
• Publication Date: Dec 2001
• Journal: 2001 Pierce's Disease Research Symposium