Mosquitoes 



places, unless they are carried by light and continued winds. 

 In heavy winds they cling to the nearest point of attachment. 

 They are carried long distances by railroad trains, and many 

 localities where mosquitoes were unknown have become infested 

 by the introduction of railways or improvement of the through 

 train service. 



Many localities can be practically rid of mosquitoes by the 

 adoption of any one of three measures: either by the drainage 01 

 the swamps or ponds in which they breed, or by the use of 

 kerosene upon the surface of the waters in which they breed, or 



Fig. 57. — Pupa of Culex pungens at left; pupa of Anopheles maculipennis 

 at right — greatly enlarged. (Author's illustration.) 



by the introduction of fish into fishless ponds so that they may 

 €at the larvae of the mosquitoes. In all mosquito-extermination 

 work, however, it must be remembered that they will breed suc- 

 cessfully in any transient pool of water or in any receptacle where 

 water is left standing for a week, no matter how small this 

 receptacle may be. They may breed in collections of water in 

 the hollows of old stumps or in old bottles or in old discarded 

 tomato cans. They breed profusely in rain-water barrels, and 

 in rain-water tanks, and in old wells, and even in cess-pools 

 where the adults are able to gain access to such pools. There- 

 fore every possible source of this kind must be hunted for when 

 one is engaged in mosquito extermination. 



103 



