Mosquitoes 



77 



ment, habits, and structure until now, if one could 

 gather together all that has been written about 

 mosquitoes in the last ten or twelve years he would 

 have a considerable library. 



Those who are particularly interested in the 

 group will find some of these books and papers 

 easily accessible, so there may be given here only 

 a brief summary of the more important facts in 

 regard to the structure and habits of the mos- 

 quitoes in order that we may more readily under- 

 stand the part that they play in the transmission 

 of diseases and see the reasonableness of the 

 recommendations in regard to fighting them. 



THE EGGS 



Mosquito eggs are laid in water or in places 

 where water is apt to accumulate, otherwise they 

 will not hatch. Some species lay their eggs in lit- 

 tle masses (Fig. 52) that float on the surface of 

 the water, looking like small particles of soot. 

 Others lay their eggs singly, some floating about 

 on the surface, others sinking to the bottom 

 where they remain until the young issue. Some 

 of the eggs may remain over winter, but usually 

 those laid in the summer hatch in thirty-six to 

 forty-eight hours or longer according to the tem- 

 perature. 



