A large species; wing-length 5-6 mm. The wings have dark spots and a diagnostic patch of pale fringe scales (silver, yellow or bronze) at the tip.
Proboscis and palps dark brown. Scutum with scattered yellow setae and a broad grey median stripe with a waxy bloom. Legs black with a bluish iridescence and a few scattered yellow scales at the apices of tibiae and femora. Wings with narrow, dark brown scales usually clustered to form 4 darker spots; wing tips with a patch of light fringe scales.
Inner clypeal seta, 2-C, forked distally into 2 to 5 branches; outer clypeal, 3-C,5 or more branched distally; post clypeal, 4-C,0 to 5-branched, 4 or 5 in most specimens. The abdominal segments have 2 dark median sclerites, the anterior one about as wide as the distance between the palmate setae. These are found in all 3 anophelines.
Anopheline mosquitoes are different in many respects from other genera. Because of these differences they were placed in a separate tribe Anophelini (Carpenter & La Casse 1955) and more recently in a separate subfamily Anophelinae (Knight & Stone 1977).
All stages of anophelines are distinct from other mosquitoes in British Columbia and there should be no difficulty in identifying them in the field. Adults have narrow wings and look very long and slender. They often adopt a well-known resting attitude, where the mosquito almost stands on its head with the proboscis, thorax and abdomen in a straight line. They indubitably adopted this position long before the evolution of man, but one is tempted to think of it as cryptic adaptation when they sit on rough-cut wooden surfaces looking deceptively like splinters.
The palps of both males and females are about as long as the proboscis; those of the male look bushy because of the long apical setae. All our species have the dark scales on some of the wing veins aggregated into spots or patches. In both sexes, the posterior margin of the scutellum is evenly rounded with a fringe of regularly distributed setae and the abdomen bears setae but no scales.
The females hibernate and can be found in winter resting under culverts, bridges and eaves and inside sheds where they usually settle in the roof. Far from civilization they hibernate in burrows, caves, hollow trees and other sheltered places.
The eggs are laid singly among vegetation at the margin of bodies of fresh water-from lakes to small ditches with slowly-flowing water. The eggs have buoyant lateral "wings," not found in our other mosquitoes, and they float horizontally.
The larvae are slim, their head and thorax relatively narrower than in the other genera. Special fan-shaped (palmate) setae on the dorsal surface of the abdomen enable them to float horizontally. In this position the eighth segment can break through the surface film. They feed here on particles from the film or "graze" on larger particles below the surface and on the bottom. Anopheline larvae have an extremely short respiratory siphon. The pecten, unlike that of our other mosquitoes does not have separate teeth, but is part of a sclerotised plate on segment VIII. Because there are few differences between the larvae of the three anophelines found in the Province, only An. earlei is illustrated.
Larvae from the related families Chaoboridae and Dixidae can be misidentified as anophelines. Chaoborid larvae, however, have prehensile antennae and are all predaceous. Of the species that could be confused with mosquito larvae, the commonest in this area is Eucorethra underwoodi which has no siphon and floats horizontally on the surface. It has a squarish head and stout bristly looking thorax and should not be difficult to identify when once seen with the slimmer anophelines. If any chaoborid larvae are reared or collected they should be separated from the mosquitoes or there may be a sharp decline in the population of the latter. Although the dixids are dark and slim like anophelines, they have the unusual habit of attaching themselves to the sides of a container in the shape of a U.
Anopheline pupae are not markedly different from those of other genera. A key that separates pupae to their genera is found in Bohart and Washino (1978).
In the past this species was confused with occidentalis which is similar but which is now thought to extend only as far north as Oregon (Curtis's remarks about occidentalis in 1967 are now believed to refer to earlei), and it was misnamed maculipennis (by Hearle, Gibson and others), a species not found in Canada.
An. earlei is widely distributed in British Columbia but less common in the lower Fraser Valley than punctipennis. The larvae develop in very cold water, usually in a slowly flowing stream or ditch with emergent marginal vegetation and in irrigation seepage in the interior. The females bite viciously and will enter houses in search of blood meals. They can attack in air so cold that no other mosquitoes are flying and are the only anophelines found in the Yukon or Alaska. In a paper entitled Canada's National Mosquito? Hudson (1978) reports finding large numbers of earlei females, many of which were engorged with blood, in a beaver lodge in central Alberta. This is obviously an ideal place for a mosquito to spend the winter. It is a host of western equine encephalitis (WEE) in Saskatchewan (Hayles et al. 1979).
"This species extends much farther north than Anopheles punctipennis but its biology is similar with several generations a year in the south. It probably feeds mainly on mammals and, often found in beaver lodges, has been called our national mosquito." (Belton 2007). Its competency as a vector for West Nile Virus is low (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) 2019. 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:
17/11/2019 6:51:38 AM]
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