Culex quinquefasciatus (originally named Culex fatigans), commonly known as the southern house mosquito, is a medium-sized mosquito found in tropical and subtropical regions of the world. It is a vector of Wuchereria bancrofti, avian malaria, and arboviruses including St. Louis encephalitis virus, Western equine encephalitis virus, Zika virus and West Nile virus. It is taxonomically regarded as a member of the Culex pipiens species complex. Its genome was sequenced in 2010, and was shown to have 18,883 protein-coding genes. American entomologist Thomas Say described Culex quinquefasciatus, which he collected along the Mississippi River, in 1823. Originally written as "C. 5-fasciatus", the name refers to 5 (quinque) black, broad, transverse bands ("fasciatus" or "fasciae") on the mosquito's dorsal abdomen. The name remains despite later revelations of more than 5 fasciae, thanks to improved microscopy. Although quinquefasciatus is the official scientific name, there are at least 5 synonymous names for this species. Cx. quinquefasciatus is a member of the Culex pipiens species complex. Smith et al. 2004 develop an assay specifically for this complex and use it to confirm that it does encompass this species. The adult C. quinquefasciatus is a medium-sized mosquito and is brown in colour. The body is about 3.96 to 4.25 mm long. While the main body is brown, the proboscis, thorax, wings, and tarsi are darker than the rest of the body. The head is light brown, with the lightest portion in the center. The antennae and the proboscis are about the same length, but in some cases, the antennae are slightly shorter than the proboscis. The flagellum has 13 segments that may have few or no scales. The scales of the thorax are narrow and curved. The abdomen has pale, narrow, rounded bands on the basal side of each tergite. Males can be differentiated from females in having large palps and feathery antennae. The larva has a short and stout head. The mouth brushes have long yellow filaments used for filtering organic materials.