Introduced to California in the late 1980’s, the glassy-winged sharpshooter has since become established as a major vector of Xylella fastidiosa, the causative agent in Pierce’s disease of grapes and a number of other important plant diseases. The incidence of fungal pathogens of Homalodisca coagulata was studied in Northern Florida and Southern Georgia for two seasons, and three new fungal species were found: Hirsutella sp., Sporothrix sp., and Pseudogibellula sp. Collections were also made throughout the Southeastern U.S. in an attempt to determine the range of these pathogens. The principal pathogen in this system was found, through molecular and morphological evaluation, to be a new species of Hirsutella, whose type specimen description is now awaiting submission for publication. Partial sequences for this Hirsutella were attained in the 28S and 5.8S ribosomal, β-tubulin, actin, and ent-kaurine synthase genes. An intron within the β-tubulin sequence made possible the design of highly specific PCR primers and the discovery of a restriction endonuclease site unique within the amplified sequence. When used in tandem, these provide a high-fidelity method for differentiating between the target Hirsutella sp., other closely related Hirsutella, such as H. thompsonii, and the other entomopathogens and saprobes commonly encountered in the field. Field work is currently underway to investigate the dynamics between the pathogen and leafhopper populations, as well as the influence of humidity on pathogen virulence. Ultimately, a better understanding of this system could lead to the implementation of this new pathogen as a biocontrol agent against H. coagulata in California.