Transgenic crops producing insecticidal toxins are now widely used to control insect pests. The benefits of this method would be lost if resistance to the toxins spread to a significant proportion of the pest population. The primary resistance management method, mandatory in the United States, is the high-dose/refuge strategy, requiring toxin-free crops as refuges near the insecticidal crops, and the use of toxin doses sufficiently high to kill insects heterozygous for a resistance allele, thereby rendering resistance functionally recessive. We propose that mass-release of harmless susceptible (toxin-sensitive) insects could substantially delay or even reverse the spread of resistance. Mass-release of such insects is an integral part of release of insects carrying a dominant lethal (RIDL), a method of pest control related to the sterile insect technique. We show by mathematical modeling that specific RIDL strategies could form an effective component of a resistance management strategy for plant-incorporated protectants and other toxins.