Towards optimization of sex-attractant pheromone use for disruption of tortricid moth pests in tree fruit.

摘要

As applied to insects, mating disruption is the practice of deploying synthetic sex attractant pheromones into an environment so as to interfere with normal mate finding, thereby reducing pest populations through diminished reproductive success. Recent investigations into the mechanisms of mating disruption have revealed that competitive attraction is the primary mechanism by which mating disruption operates for moth pests. In the competitive mechanism, attraction to a pheromone is the required first step toward disruption. Research presented here used the competition framework to inform development and testing of new mating disruption formulations and deployment tactics with the aim of maximizing efficacy while minimizing costs. A novel release matrix consisting of paraffin wax and ethylene vinyl acetate (hot glue) was developed for inexpensive production of an easy-to-apply and modifiable pheromone dispenser. In the laboratory, this matrix regulated the release of the pheromones of several tortricid moth pests within a desired range over several months. In the field, this matrix proved to be a good lure for possible use in monitoring programs. When applied at high densities (up to 10800 ha-1), matrix dispensers on string suppressed sexual communication of Oriental fruit moth, obliquebanded leafroller, and codling moth populations, although sometimes not as well as high-releasing commercial dispensers. In large field cages, disruption of Oriental fruit moth operated competitively when dispensers released pheromone at ca. 0.04 &mgr;g hr-1. But disruption switched to a non-competitive mechanism when pheromone was released at ca. 60 &mgr;g hr-1. These studies also demonstrated that an attract-and-remove scenario would enhance Oriental fruit moth control. Trapping after attraction improved suppression of sexual communication 10-fold over competitive disruption achieved by releasing pheromone at ca. levels released by female moths. A patent-pending microtrap was developed primarily for use in an attract-and-remove control program. Laboratory and field investigations reported here justify the trap design and function for codling moth. An attract-and-remove study also demonstrated proof-of-concept that obliquebanded leafroller could also be controlled under an attract-and-remove strategy. Collectively, this research demonstrates several ways costs may be reduced while maintaining or improving efficacy when using sex pheromones for pest management. These developments should encourage broader adoption of this environmentally friendly method of pest control.