304 INSECTS AFFECTING MAN AND HOUSEHOLD 



Mosquitoes. There are a large number of species of mosqui- 

 toes in the United States; the two most dangerous are Anopheles 

 (Fig. 312), a particular species of which is an intermediary host for 

 the germ of malaria; and Stegomyia, dangerous because it spreads 

 yellow fever (Fig. 313). The first-named genus is sometimes found 

 in localities where malaria does not exist, and under those condi- 

 tions, of course, it is not a dangerous insect. However, all mos- 

 quitoes are annoying, and, although the male is innocuous, since 



FIG. 312. The malaria-bearing mosquito. (Lugger.) 



it does not bite, the female mosquito is the cause of many wakeful 

 hours. It is also of commercial importance in certain sections, 

 in that it seriously affects the condition of stock and milk cattle. 

 Out-of-door occupations and pleasures in some localities are im- 

 possible during the summer on account of the presence of this 

 pest. 



Life History. While details of life histories vary strikingly, 

 there being marked differences in the length of life cycles, in a 

 general way we may include all species in making the statement 



