PRINCIPLES OF MOSQUITO CONTROL 287 



places contributing to the mosquito fauna characteristic of the pro- 

 tected district. 



The third step is the provision of funds necessary to seek out and 

 treat with oils and larvicides all mosquito breeding waters of both a 

 permanent and temporary character and to accomplish such an amount 

 of permanent removal of mosquito breeding waters that within a hmited 

 period of years this phase of the work may be brought to completion. 

 The only limitation imposed upon funds for temporary treatment of 

 mosquito breeding waters is concerned with those mosquito breeding 

 waters, the permanent removal of which is provided for. The purpose of 

 the temporary treatments with oil or larvicides is to afford the citizenry 

 of the designated area protection against mosquitoes from the begin- 

 ning of the project. The purpose of providing funds annually for elimi- 

 nation of a reasonable proportion of the permanent mosquito breeding 

 waters is designed to start a process which will eventually render the 

 increasing freedom demanded by the population possible of realization. 



The fourth step is to form an organization to seek out during the 

 mosquito breeding season on a regular weekly schedule all actual mos- 

 quito breeding occurring within the designated territory, to treat in 

 such a fashion as may be practical all such breeding found before it has 

 a chance to develop to adult mosquitoes. In addition the above organi- 

 zation must be so constructed that it can expand its activities in case 

 of heavy rainfall to cover the thousands of temporary pools, created 

 by this rainfall, and in which additional mosquitoes can develop. 



The fifth step is to make intelligent use of mechanical gauges to 

 measure the effectiveness of the work and to indicate where special ef- 

 fort should be focused. 



Drainage is probably the most practical method of removing mos- 

 quito breeding waters from the upland. There are a few instances in 

 which it is financially practicable to fill mosquito breeding pools. Such 

 drainage is naturally devoted to permanent breeding places. Rarely is 

 it practicable to use it on temporary breeding places. There is nothing 

 new or novel about this drainage. It is simply opening outlets to ponds, 

 pools, and swamps by which the water can be drawn away. 



There will be many instances of permanent mosquito breeding places 

 which for one reason or another are undesirable to drain. Such places 

 should have their banks sharpened and their waters stocked with min- 

 nows of game fish. The purpose of sharpening the banks is to prevent 

 aquatic plants from forming a screen behind which the wrigglers can 

 develop without danger from the fish. There are many artificial pools 

 created for the sake of beautification of private property. Such pools 



