N. J. Mosquito Extermination Association 71 



The idea of impounding water to suppress mosquito breeding 

 is rather foreign to the general conception of the effect of im- 

 pounded water upon mosquito production. The relation which 

 impounded water will bear to mosquito production depends alto- 

 gether upon the conditions under which the work is done and the 

 changes brought about in comparison to the natural conditions. 

 In the question of impounding water in a bayou we must con- 

 sider the natural character of such a stream and the relation of 

 the stream to the roadways of the plantation and to the habita- 

 tions of the people who cultivate the land. The banks of the 

 bayou are the logical location for the houses of the tenants, and 

 it is important to control breeding of Anopheles in this nearby 

 source. The bayou under natural conditions is productive of 

 these mosquitoes, while the change from swamp-like to lake-like 

 conditions does not favor such production. The change in con- 

 ditions is brought about by the preliminary clearing of the vege- 

 tation and by the provision for a permanent level of water suffi- 

 ciently high to suppress the growth of aquatic and semi-aquatic 

 vegetation. Following these operations the maintenance of a 

 clean margin is all important. 



