Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2009
Publication Date: June 1, 2009
Citation: Sisterson, M.S. 2009. Changes in the epidemiology of Pierce’s disease in California due to introduction of the glassy-winged sharpshooter. Phytopathology 99:S170. Technical Abstract: Pierce’s disease is caused by the xylem limited bacterial pathogen, Xylella fastidiosa. This pathogen is vectored by xylem feeding insects and has been present in California for more than 100 years. Within California there are three management regions that have different key vectors: the North Coast, the Central Valley, and Southern California. On the North Coast the key vector is the native blue-green sharpshooter (Graphocephala atropunctata). In the Central Valley, there are two native vectors and one exotic vector. The two native vectors are the green sharpshooter (Draeculacephala minerva) and the red-headed sharpshooter (Xyphon fulgida). Both are widely distributed in the Central Valley. In contrast, distribution of the exotic glassy-winged sharpshooter (Homalodisca vitripennis) is limited to southern portions of the Central Valley and throughout Southern California where it is the sole key vector. Two epidemics of Pierce’s disease occurred approximately 10 years after introduction of the glassy-winged sharpshooter into California. The first occurred in Southern California and was followed by an epidemic in the southern portion of the Central Valley. These epidemics resulted in losses typically not observed with native vectors. Factors hypothesized to contribute to these losses were aspects of glassy-winged sharpshooter ecology, the cropping landscape in Southern California, climate, and the absence of a management program for a newly introduced vector.