IMPACT OF MULTIPLE-STRAIN INFECTIONS OF XYLELLA FASTIDIOSA ON ACQUISITION AND TRANSMISSION BY THE GLASSY-WINGED SHARPSHOOTER

• Author(s): Cooksey, Donald; Costa, Heather; Gispert, Carmen;
• Abstract: In this project, studies were conducted to 1) develop a method to detect and differentiate multiple strains of Xylella fastidiosa in individual glassy-winged sharpshooters (GWSS,) and 2) determine the relative ability of an individual GWSS to simultaneously retain or transmit two strains of X. fastidiosa. Strain-specific primers were developed that can detect and differentiate the Pierces disease strain (PD) and the oleander strain (OLS) present in extracts from individual insects fed on X. fastidiosa-infected grape and oleander plants. After feeding on infected grape and oleander source plants for one day each, 76% of surviving adults tested positive for one or both strains of X. fastidiosa. The majority of individuals tested positive for only one strain of the pathogen (29% PD, 41% OLS), and only 7% tested positive for both strains; 24 % tested negative. Overall, individual insects transmitted the pathogen 39% of the time (13% PD, 26%OLS). Thus, only about half the insects that tested positive for X. fastidiosa actually transmitted the pathogen to a susceptible host. Although each individual used in transmission studies was exposed to both strains of the pathogen and both types of test plants, in all cases an individual insect transmitted only one strain of the pathogen, never both.
• Publication Date: Aug 2003
• Journal: 2003 Pierce's Disease Research Symposium