This paper discusses the establishment of insect pest control in Japan for preventing disease transmission. In the late nineteenth century, after the establishment of tropical medicine in Great Britain, many insects were recognized as vectors. However, it was only after the 1920s that the control of insects became a social agenda in Japan. In colonial Taiwan, the transformation of the environment was initiated to exterminate the mosquito vectors of malaria. Almost simultaneously, in the metropolises of the Japanese mainland, extermination of flies was initiated through mass mobilization. This paper compares the scientific framework of the colonial and metropolitan context and throws light on the participation of parasitologists, entomologists, and bacteriologists in studying insect vectors. It also examines the mobilization of scientists during the Asia Pacific War and how it changed the framework of studies related to insect-borne diseases. Finally, I discuss the fact that mobilization under conditions of war rendered post-war control of insect vectors.
