ABSTRACT
Although from the beginning the Tennessee Valley Authority (TVA) placed principal reliance for mosquito control upon biological or naturalistic control measures, extensive use was made of supplementary measures in the form of chemical larviciding (TVA and the United States Public Health Service 1947). Between 1933 and 1943, developments in larviciding techniques consisted principally of improvements in equipment for hand and boat application of kerosene and black oil larvicidal mixtures and aerial applications of Paris green dust. As DDT and other more effective insecticides became available, the TVA began testing the more promising ones and developing satisfactory equipment for their application. Aeroplane application of DDT was first carried out by the TVA in co-operation with the US Department of Agriculture in 1943. Because of the demonstrable effectiveness of DDT at low rates of application (0.05-0.10 kg/ha) and the resultant economics of aerial distribution, DDT was adopted for TVA use in mosquito control operations. The use of Paris green dust for aerial applications was completely phased out by 1946 and boat applications of kerosene and black oil mixtures were discontinued in 1949. Later, spray equipment was devised to replace the aerosol generating equipment. In the early 1950s, the use of fixed-wing aircraft equipped to produce an aerosol or mist type spray was evaluated, but their use was discontinued shortly after it began.
