PROBLEM TO BE SOLVED: To provide a Diptera larva insecticide that can exterminate the outbreak source of Diptera larvae on the basis of excellent knockdown effects by a short time treatment, makes the outbreak source itself clean and can prevent outbreak of Diptera larvae in a treatment of a small water system such as a drain outlet of a general household, a water receiver of flowerpot, etc., and a Diptera larva exterminating method using the same.SOLUTION: The Diptera larva insecticide includes a bleaching component or the bleaching component and a surfactant as active ingredients. Preferably the bleaching component is one or more kinds selected from oxygen-based bleaching agents being a hydrogen peroxide adduct, a hydrogen peroxide solution and a hydrogen persulfate, and the surfactant is an anionic surfactant and/or an amphoteric surfactant. Preferably the Diptera larva insecticide further includes an insecticidal component besides them.
