A method and composition for controlling insects is disclosed. A method and composition are most effective for killing insect populations in enclosed spaces, although direct contact with insects may also be effective. The method involves exposing the insects to 1,4-dimethylnaphthalene for a sufficient period of time to cause death to the same, wherein the insects may then be more readily destroyed. In enclosed spaces which are to be disinfected, a mist or vapor of 1,4-dimethylnaphthalene may be diffused into the space with the space sealed for a sufficient period of time to eliminate insects.