Culex tarsalis mosquito (close anterior view)

In this photograph, the Culex tarsalis mosquito is about to begin feeding after landing on the skin of what would become its human host. Note the light-colored band wrapped around its dark-scaled proboscis (A), the multiple, similarly light-colored bands wrapped around the distal appendages (ie, the tibia and femur) of its forelegs and middle pair of legs (B), and the presence of one of the two silver markings on its dorsal scutum (C). The epidemiologic importance of C. tarsalis lies in its ability to spread Western equine encephalitis, St. Louis encephalitis, and California encephalitis. When this image was created in 2005, C. tarsalis was the main vector of West Nile virus in the western United States. Photograph by CDC/James Gathany in 1976. (Source: Public Health Image Library, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia. Image 7957. Public domain.)