Habitats and dispersal of the principal leafhopper vectors of Pierce’s Disease in the San Joaquin Valley

The green sharpshooter (DraeculaceXhala minerva [Ball]) and redheaded sharpshooter (Corneacephala fulgida [Nott.]), important leafhopper vectors of Pierce’s disease bacterium to grape and alfalfa, commonly inhabit permanent pastures and weeds alongside or in cropped fields. The species composition, stand, vigor, and persistence of grasses and other plants determine the extent to which sharpshooter populations can develop. Bermuda-grass (Cynodon dactylon) is a highly preferred host of both sharpshooters and watergrass (Echinochloa crusgalli) is a favorite host of D. minerva. Irrigation and weed control practices that produce succulent stands of preferred host plants thus increase sharpshooter populations.