DAHLGREN, THE MALARIA MOSQUITO 7 



The number of mosquitoes in a large swarm is beyond compre- 

 hension, and accounts of "immense clouds filling the air" — "like a 

 column of smoke," or "like a dense wall, miles in length," are by no 

 means infrequent. L. O. Howard, 1 Chief of the Bureau of Entomology 



at Washington, describes a swarm observed in Texas, the 



,,,.,., . .. . . i i • i Mosquito 



mam body or which was three miles wide, ana which re- Swarms 



quired nearly five days to pass a given point. Such mi- 

 grations of mosquitoes, though they are usually on a smaller scale, 

 account for the sudden appearance of the insects in areas from which 

 they were previously absent, and their equally sudden disappearance. 



As a rule, mosquitoes are frail insects and weak flyers. In rain or 

 winds they hastily seek shelter. The Malaria Mosquito (Anopheles) 

 avoids places where draughts exist, and seldom flies more than a few 



hundred yards. An Indian species of the genus is known __ ... 



} & Habits 



which flies a quarter of a mile, but rarely as far as half a 



mile. The Malaria Mosquito as a rule, spends its entire life in the 



immediate neighborhood of human dwellings. 



Mosquitoes are most active at early dawn and after sunset. They 

 seem in general to avoid strong light and to prefer dark colors. The 

 hours of daylight are spent by most species hiding in some secluded spot 

 in a tuft of grass or a bush, while the Malaria Mosquito finds some 

 dark corner indoors, where it passes the day. There are, however, 

 some notable exceptions to this general rule. The Yellow Fever Mos- 

 quito flies at almost any time of day, except noon, and several tropical 

 species resemble it in this respect. 2 



In the autumn all the males die, while the fecundated females seek 



winter quarters. The Malaria Mosquito, which is essentially a house 



mosquito, may be found hibernating in dark corners in „., 



1 . , ■ . , . Hibernation 



cellars, sheds or attics. The strictly out-of-door species 



find winter quarters in the woods or in the fields. In the arctic regions 

 mosquitoes find suitable hibernating places under moss. Large num- 

 bers of the insects undoubtedly perish during severe winters, but, under 

 ordinary conditions, enough mature females survive to furnish locally 

 the first brood of the following season. A warm day in early spring 

 brings the insects out of their stupor; on a sunny day in mid-winter 



1 Mosquitoes, How they live, etc., p. 22. See also Theobald's Monograph of the 

 Culicidse of the World for several interesting accounts: 



-One of the local species of Anopheles (A. crucians) is a " daylight mosquito." 



