MOSQUITOES 



125 



Canal, has been made possible mainly through the control of 

 malarial and yellow-fever mosquitoes. 



Of the ten genera of mosquitoes of North America, Anopheles, 

 A<'<li'x (a e' dez), and Culex concern us chiefly. There are taree 

 species of Anoph- 

 eles distributed 

 throughout the 

 country, and it 

 is important to 

 remember that it 

 is through these 

 mosquitoes only 

 that malarial fe- 

 ver is spread. 

 This disease is 

 not as fatal as 

 some others, but 

 is important be- 

 cause so widely 

 distributed and 

 because in ma- 

 larial countries 

 from 25 to tiO 

 per cent of the 

 people are af- 

 flicted. In the 

 United States, 

 according to the 

 estimate of Dr. 

 L. O. Howard, there occur 3,000,000 cases, causing a loss of 

 $100,000,000, annually. In India, where the fever assumes a 

 fatal form, 5,000,000 people have succumbed to it in one year. 



Anopheles is particularly active during the early part of, the 

 night. It may be distinguished from other mosquitoes at a 



03. 



edes calopux Yellow-fever mosquito 

 Egg, larva, pupa, and adult 



