Control of Black Flies on Small Islands in Kagoshima Prefecture, Japan

Among the small islands in Kagoshima Prefecture of Japan, Nakanoshima Island and Kuroshima Island are known to be inhabited by black flies that feed on human blood. These two islands share similar topographical features: rivers are large relative to the island size, flat land is scarce, and most settlements are located near the coast. The species that feeds on humans on these two islands is Simulium japonicum, which is distributed from Hokkaido to Okinawa in Japan. On the larger islands, it inhabits fast-flowing rivers in relatively highland areas; however, on these two islands, it occurs in residential areas near the coast, causing bloodsucking damage. Although the local government has been controlling black flies since the 1980s, and the damage has been significantly improved, some residents still complain of bloodsucking damage.