An improved method for the extraction of viral RNAs was developed to facilitate the reverse transcription (RT)-PCR detection of mosquitoes infected with Western equine encephalitis virus or La Crosse virus. The solubilization method, which uses only EDTA and sodium dodecyl sulfate (SDS) followed by dilution of sample, allows accurate viral detection through the use of random hexamers for the RT followed by specific primers for the PCR. Identities of the reaction products were confirmed either by sequencing or restriction endonuclease digestion. Previous methods for the extraction of RNA for the coupled RT-PCR depended on combinations of guanidinium isothiocyanate, acid phenol, detergents and multiple centrifugations. Ideally, routine detection of viral RNAs for diagnostic purposes should bypass many of the above steps, while still providing a sensitive assay. Our level of detection is 1 infected mosquito in a group of 100.