Culex pipiens

Culex pipiens is a species of mosquito commonly referred to as the common house mosquito or northern house mosquito. Native to Africa, Asia and Europe, it is now widely distributed in temperate regions on every continent except Antarctica and is one of the most common mosquitoes found in human habitats in temperate parts of the northern hemisphere. A major vector of some viruses, it can be abundant in cities, especially those with poor wastewater management. It is the most common mosquito to the northern regions of the US. Culex pipiens is the type species for the genus Culex.

Culex pipiens includes two morphologically indistinguishable forms, Culex pipiens form pipiens and Culex pipiens form molestus. Despite their morphological similarity, the two forms exhibit striking ecological and behavioral differences. Form pipiens lives above ground and primarily feeds on birds. Form molestus, also known as the London Underground mosquito, can live under ground and frequently bites mammals including humans. The two forms are largely genetically isolated in Europe, but have been reported to hybridize in the United States. Importantly, hybrids appear to have intermediate feeding behavior, biting both humans and birds, and are implicated as a bridge vector in the maintenance and transmission of the West Nile virus from birds to humans.