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A small to medium-sized, dull brown mosquito with unbanded tarsi; wing length 3.5-4 mm. It is appropriately called the common house mosquito.
Proboscis and palps dark. Pedicels uniformly dark brown. Scutum covered with golden brown scales. Abdominal tergites black with pale basal bands, widest at the centre, narrowing laterally before joining lateral triangular pale patches. Tarsi brown. Wings dark-scaled.
Antennae long, spiculate, apical third constricted beyond 1-A. Head setae 5 and 6-C 4 or more branched. More than 35 slipper-shaped comb scales in a triangular patch. Siphon 4-5 x 1, pecten on basal quarter. 4 many-branched setae inserted beyond pecten, penultimate one slightly out of line, placed more dorsally. Saddle surrounding anal segment.
Linnaeus used culex, the Latin word for mosquito when he described the common house mosquito, Culex pipiens. All mosquitoes described in the following 50 years were placed in this genus. In 1818 Meigen decided that there were at least two other major types of mosquito, which he therefore renamed and placed in the genera Anopheles and Aedes. Only three Culex species, one of which is pipiens, are known to occur in British Columbia.
The pale cuticle gives the adults an overall brown colour. The females can readily be separated from those of Anopheles by the short palps and trilobed scutellum, from those of Aedes by the blunt abdomen and from Culiseta and Mansonia females by the absence of both pre- and postspiracular setae.
Eggs are laid in rafts on the surface of almost any standing water.
Larvae have a long narrow respiratory siphon with a short pecten at the base composed of rather small teeth. The siphon lacks basal seta 1-S, but four or more pairs of branched setae arise ventrally beyond the pecten.
Pupae should be kept alive and allowed to emerge.
All our species overwinter as fertilized females and can produce several generations a year.
It is hard to believe that pipiens was once rare in the province. Hearle wrote in 1926 "It would appear that this species has been introduced comparatively recently". It "has been taken, but is very rare, and so far has been found at one point only" (Vancouver). In recent years, it has spread widely and increased enormously in numbers and is now common from Vancouver Island at least to the Okanagan.
On emergence from hibernation fertilized females seek a blood meal and soon lay their eggs in boat-shaped rafts on the surface of water in sewage lagoons, drainage ditches, catch basins, paddling pools, tin cans and also in natural open pools and swamps. The new generation matures, mates and lays its eggs in three to five weeks. Several generations are produced each season, the number depending on the temperature of the breeding site. In the Lower Mainland I have seen groups of about ten males swarming over Douglas Spirea bushes in summer and close to the south walls of buildings later in the season, often until the first killing frost. By then the mated females have found humid places to hibernate, often within buildings.
There has been much debate about the varied behaviour of this species and whether or not there are two strains, only one of which bites humans. In the many ditches of the Richmond area it is often abundant, yet seldom annoying outdoors. On the other hand, it is a pest when it enters houses in late summer and bites the inhabitants. Most residents in the southwest of the Province have experienced its whine around their heads as they tried to sleep. Although the Richmond strain seldom bites outdoors it has been successfully colonized and will feed on guinea pigs in a warm humid laboratory (Gillespie 1978). Specimens naturally infected with SLE and WEE have been found in Washington State (Gjullin & Eddy 1972).
"This species was probably introduced to the west coast of North America in the late 1800’s. Since the 1920’s it has spread across the south of the Province and into Vancouver Island and is now one of the commonest mosquitoes in artificial containers (e.g. rain barrels and paddling pools) drainage ditches and storm sewers, particularly those contaminated with organic matter. It feeds primarily on birds but comes indoors to bite on warm summer nights, often making itself heard in the bedroom. It is a proven vector of WNv, WEE and St Louis Encephalitis (SLE). It was found in Prince George in 2004 and may be widely distributed in the southern half of the Province. This species is a carrier of West Nile virus." It is a competent vector for West Nile Virus (Belton 2007).
Belton, Peter 2007. British Columbia mosquitoes as vectors of West Nile virus. Peter Belton web site. Simon Fraser University.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2021-10-19 11:46:21 AM]
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