A method for controlling a population of target insects comprising providing a gene comprising a coding sequence encoding one constituent of an enzyme/pro-pesticide system and a regulatory region operatively linked to said coding sequence. The regulatory region of the present invention regulates expression of said coding sequence in a target insect of said population of target insects in a sex specific manner. The method of the present invention further comprises transforming a plurality of said target insects with said gene, and allowing said gene to spread within the target insect population. The method further comprises administering to said population of target insects the remaining constituent(s) of said enzyme/pro-pesticide system wherein said enzyme catalyzes the conversion of the pro-pesticide to a pesticide.