â¢ DDT was a commonly-used pesticide for insect control in the United States until it was canceled in 1972 by the United States Environmental Protection Agency (EPA). Why was DDT used? â¢ DDT was initially used by the military in WW II to control malaria, typhus, body lice, and bubonic plague (1). of malaria fell from 400,000 in 1946 to virtually none in 1950 (3). and Asia for this purpose. â¢ Farmers used DDT on a variety of food crops in the United States and worldwide. DDT was also used in buildings for. pest control. â¢ The reason why DDT was so widely used was because it is effective, relatively inexpensive to manufacture, and lasts a. long time in the environment (2).