(see www.cdc.gov/ncidod/dvbid/westnile/mosquitospecies.htm). The vast majority of isolates came from Culex pipiens, Cx. quinquefasciatus and Cx. restuans. Numerous isolates have also come from several potential accessory vectors, e. g., Cx. tarsalis, Cx. salinarius, Aedes albopictus, Ae. vexans and Cx. nigripalpus.