MOSQUITOES AND DISEASE 



91 



Control of Mosquitoes. — The Anopheles mosquito will breed 

 wherever there is a small accumulation of water. Small creeks 

 through meadow land, the ditches and gutters or .drains along 

 railroad and other embankments, and the shallow overgrown 

 edges of ponds or swamp areas are favorite breeding places (Fig. 

 56). Pools containing grassy or other vegetation are nearly 

 always infested, and ponds with lily pads, dock, sagittaria, and 

 other plants of a similar character, are danger points. The 



Fig. 57. 



Oiling 



a pond near a railroad track where mosquitoes breed. 

 (After Herms.) 



larvae need only a mere film of water, and this being found over 

 a leaf or at a grassy edge, protects them from the usual natural 

 enemies ... no other mosquito has as wide a range of breeding 

 places as have the species of Anopheles (Smith). 



Two methods may be used to prevent mosquitoes from breed- 

 ing in such places. The best method is to remove all receptacles 

 in which water may collect and to drain all wet places. The 

 other method is to treat the breeding places so as to kill the wig- 

 glers (larvae and pupae). Many different substances have been 



