286 ILLINOIS STATE ACADEMY OP SCIENCE 



times true air breathers, securing their supply of air 

 through respiratory siphons located on their tails. In 

 two or three days, the wigglers or larvae develop into 

 pupae. Both types of pupae resemble very closely the 

 figure of the comma (,). In two or three days the shell 

 of the pupa splits and the adult mosquito emerges. 



The Anopheles mosquito may be distinguished from 

 other types of mosquitoes by the definite markings on 

 the wings and by the position it assumes when resting 

 or feeding. When resting or feeding its proboscis and 

 body are in the same line, and at an angle from 45 to 90 

 degrees with the surface upon which it is resting. The 

 ordinary Culex mosquito has transparent wings and 

 when resting, keeps its body parallel with the surface. 



The life habits of the two types of mosquitoes are dif- 

 ferent in a great many respects. The Anopheles appar- 

 ently has the better taste and will not breed abundantly 

 in sewage-polluted water. Anopheles crucians breed 

 most abundantly in swamps and fresh marshes; Ano- 

 pheles pmnctipennis prefer slowly moving streams, while 

 Anopheles quadrimaculatus choose woodland pools and 

 the shallow portions of lakes and ponds. The Anopheles 

 mosquito very seldom bites in the daytime and its song 

 is much quieter and less annoying than that of other 

 types. It does most of its work between the hours of 

 sunset and sunrise. The Culex mosquito is very annoy- 

 ing both as to song and bite, and will make its attacks 

 in the daytime as well as at night. 



Only Anopheles mosquitoes, and only the females of 

 that species, can spread malaria. In the "dark ages" of 

 malaria it was commonly believed that the disease was 

 caused by breathing or contact with air in low places or 

 which had passed over swamps or stagnant ponds, espe- 

 cially at nighttime. Whence the name malaria from two 

 Latin words, "mal" meaning bad and "aria" meaning 

 air. There was a grain of truth to this unscientific but 

 popular understanding of the cause of malaria, for it is 

 true that the Anopheles mosquito that can spread ma- 

 laria breeds in swamps and stagnant waters and flies 

 almost entirely after dusk or dark. 



