The objective of this research was to char- acterize and identify two double-stranded RNA molecules previously detected in hypovirulent iso- lates of Sclerotinia homoeocarpa, the causal agent of dollar spot of turf. These hypovirulent isolates are being used as biological control agents for dollar spot.This research characterized and identified two new viral agents in infected isolates of S. homoeocarpa, and identified OnuMV3a as the virus associated with hypovirulence in infected isolates. These results will enable us to continue the development of this biological control strategy through conducting environmental fate and persistence studies of this virus, characterizing the mechanisms of action by which this virus reduces the virulence of infected isolates, and through determining the role of this virus in native populations of the pathogen.