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: Xylella fastidiosa (Xf) is a xylem-limited bacterium that causes a number of plant diseases such as Pierces disease (PD) of grapevines, almond leaf scorch, alfalfa dwarf, citrus variegated chlorosis, leaf scorch of live oak, pear leaf scorch, and oleander leaf scorch (OLS). Recent studies by Purcell et al. have shown that oleander leaf scorch is caused by a different strain of Xf than the strain that causes PD. Thus far, two strains of Xf have been identified in Southern California; one that causes Pierces disease of grapevines and almond leaf scorch, and another one that causes oleander leaf scorch (OLS). The strain that infects oleander does not appear to infect grape, and the strain that infects grape does not appear to infect oleander. We are interested in documenting the ability of glassy-winged sharpshooter (GWSS) to acquire and transmit more than one strain of Xylella at a time, and to determine the effects of a previous infection with one given strain of Xf on the subsequent acquisition and/or transmission of a second strain. We will document important aspects of the transmission process to determine 1) if the insects can only acquire and transmit one strain of the pathogen at a time, or if they are capable of transmitting more than one strain at a time, and 2) if the order of exposure is important to acquisition or transmission. This type of information is critical to the development of management strategies, particularly those that attempt to utilize mechanisms involving competitive less virulent strains of bacteria, or other methods of control that interfere with vector competence.
• Publication Date: Dec 2001
• Journal: 2001 Pierce's Disease Research Symposium