VECTOR COMPETENCE OF AEDES DORSALIS (DIPTERA, CULICIDAE) FROM MORRO BAY, CALIFORNIA, FOR WESTERN EQUINE ENCEPHALOMYELITIS VIRUS

In laboratory vector competence studies, Aedes dorsalis (Meigen) colle cted from Morro Bay, CA, did not vertically transmit sympatric strains of western equine encephalomyelitis virus (WEE). This population of A e. dorsalis was highly susceptible to oral infection and was a compete nt horizontal vector of WEE. The E2 region of the viral genome of the 3 virus strains isolated from Ae, dorsalis in Morro Bay were closely r elated genetically to a strain of WEE isolated in 1953 from a geograph ically separate location that is used regularly in the laboratory. The se laboratory findings support recent field research and indicate that Ae, dorsalis probably does not play a significant role in WEE persist ence in coastal California.