PURPOSE: An insecticide preparation that is composed of both a composition that leberates heat by reaction in the presence of water and oxygen and an insecticidal constituent that evaporates or vaporized with the heat liberated by the composition, thus killing insect pests such as mosquitoes by no use of electricity of fire with safety and ease.

CONSTITUTION: The objective insecticidal composition contains both of a composition that consists of activated carbon, iron dust, inorganic salt and so on and liberates heats by their reaction in the presence of water and oxygen and of an insecticidal constituent that vaporizes or evaporates with the heat generated by the composition. The above heat-liberating composition is mixed with a powdery or granular insecticide. The insecticidal constituent is varied, according to the purpose, place to be applied, the kind of the insect, for example, fluoride, DDVP, nicotin or organophosphate is used. When it is applied to mosquitoes, the constituent is preferably a pyrethroid such as pyrethrin which is less harmful to men and animals. The resultant insecticide is kept from air, when stored and the composition is controlled so that the oxidation reaction and vaporization complete in 12W13hr.