INSECT control designed to prevent human disease has been carried on for only half a century-but this short epoch is characterized by an almost incredible range of technical, administrative, and organizational developments. It is regrettable that only a few of those believed to be important in advancing insect control as a public health practice can be mentioned. The transfer of disease by insects t was first demonstrated in 1893 when Smith and Kilborne showed that Texas cattle fever was spread by ticks.' Within twenty years it was found that some of the more important diseases of manmalaria, yellow fever, plague, typhus, and many others-were carried by insects. These discoveries provided the epidemiologic basis for a new but important principle in environmental sanitation, namely, communicable disease control by preventing contact between man and insect vectors of infection. By the turn of the century, the life cycles of certain disease-transmitting insects -mosquitoes, house flies, fleas, and lice-were known. This information was essential in developing effective control principles and practices. Those available at the time included drainage