Plate xii. top. In urban areas street drainage catch basins are a source of 

 prolific breeding of house mosquitoes, bottom left. Hand oiling sewer catch 

 basin by using ordinary garden watering can or hand sprayer (not illus- 

 trated) practicable in densely populated areas where heavy traffic interferes 

 with the use of power equipment, bottom right. This power sprayer, de- 

 signed for treating catch basins and flooded cellars, is equipped with a long 

 hose to permit the operator to work at a distance from the truck. Pressure 

 is developed in oil tank by utilizing a small air compressor driven by the fan 

 belt of the truck motor. 



