MOSQUITOES 643 



sub -family Anophelince. It has been repeatedly proved 

 that infected mosquitoes convey infection, and^that 

 human beings protected from mosquito bites may_live 

 in the most malarious districts without contracting the 

 disease. 



Mosquitoes (Culicidce) are distinguished from other mosquito - 

 like insects by the fringe of scales on the wings. The common 

 mosquitoes belong to the sub -family Culicince. The Anophelince 

 are usually less abundant (but there is great variation in different 

 districts), and bite mainly at night ; the females alone are blood- 

 suckers. Some species breed in natural collections of stagnant, 

 others in slowly running fresh, water well supplied with lowly 

 forms of vegetable life. If the head of a mosquito be examined 

 with a hand-lens, three sets of appendages will be noticed. In the 

 middle is the stout proboscis containing the stinging and suctorial 

 apparatus ; situated at the base of this are two palpi, one on 

 either side, and outside these again are two antennae, which 

 are more or less hairy. In Anophelince, both male and female, 

 the palpi are as long as the proboscis ; in the female Culex (also 

 in Stegomyia and many other genera) they are short and stumpy. 

 In Anophelince the scales on the veins of the wings are usually 

 arranged in alternating light and dark patches, giving a speckled 

 or dappled appearance, different as a rule from anything seen in 

 Gulex. (Some Culices have a similar arrangement, and it is 

 wanting in A. maculipennis and A. bifurcatus.) The front or 

 costal margin of the wing in Anophelince is almost always marked 

 with dark blotches. A dorsal plate, the scutellum, is present at 

 the posterior border of the thorax. In Culicince the scutellum is 

 trilobed, in Anophelince it is simple and rounded. Anopheles, as 

 a whole, is a more slender insect than Culex, and when at rest its 

 body is all in one line, whereas Culex is angular or hump-backed. 

 The important species known to carry malaria are Anopheles 

 maculipennis in Europe, N. Africa, and N. America, A. bifurcatus 

 in Europe, Myzomyia funesta and Pyretophorus costalis in Central 

 and W. Africa, and Cellia argyrotarsis in tropical America. Other 

 species, e.g. Myzorhynchus sinensis, Cellia Kochii, and others, are 

 less important carriers. 



(On Mosquitoes, see Alcock, Entomology for Medical Officers, 

 ed. 2, 1920.) 



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