Pierce’s Disease of grapes is caused by the bacterial pathogen, Xylella fastidiosa. Xylella is primarily spread by a leafhopper, the glassy-winged sharpshooter, GWSS, Homalodisca coagulata, but it is also spread by other leafhopper species. Our research on leafhopper pathogens has identified the presence of viral pathogens. Examination of viral infection by an insect iridovirus demonstrated that the virus infected the cells of many different tissues of the GWSS. Virus infection reduced the longevity of GWSS adults, which also reduced the overall fecundity of infected females. Use of naturally occurring viral pathogens to reduce GWSS populations is discussed.