Population structure in the Culex pipiens complex of mosquitos.

Mosquitos of the Culex pipiens complex offer unique opportunities for study of the mechanisms that separate populations and of the possible advantages of the blood-feeding habit. C. pipiens is a polytypic species in which there are at least three major adaptations to environment. The tropical quinquefasciatus (fatigans) is a generalized blood-feeder dependent on the year-round availability of a variety of hosts. The obligate blood-feeding pipiens form of the temperate zone appears to be adapted to feeding upon nesting birds. The autogenous molestus form is essentially non-blood-feeding. Additional variants are present in different parts of the world.The variety of devices that serve to separate these different populations pose difficult problems for the taxonomist.