Mechanisms of Mating Disruption in Moths

Abstract

Insect control (population regulation) by the use of synthetic semiochemicals to disrupt normal mating behavior is now operational for a number of species of Lepidoptera. But, although there have been successes, there have also been failures. Moreover, in some instances a previously successful operation has subsequently failed. Also, there is always the possibility that the technology can be improved, or that it can be made to work more cheaply. In order to improve efficacy and to be able to fix it when it is broken, we have to understand how it works. Unfortunately, the mechanisms of how disruption works are still largely unknown. Because the technique involves complex behavioral interactions between insects in a communication mode (olfaction) to which humans have little inherent affinity, understanding disruption is not easy. First we need to understand what we are trying to disrupt—that is, the mating behavior of the insects. Then we have to know the characteristics of the formulation used to disseminate the disruptant chemicals and how the synthetic material behaves in the airspace, and finally we have to understand the behavior and population dynamics of the target insect that affects its susceptibility to mating disruption. This chapter will therefore be divided into four sections: first, a brief discussion of mating behavior in moths; second, a review of the possible mechanisms by which mating behavior of moths may be disrupted; third, a discussion of the mode of action of different disruption formulations; fourth, a review of some of the factors which affect the success of mating disruption as a control technique.