Potential of an Attractive High-Rate Navel Orangeworm (Lepidoptera: Pyralidae) Pheromone Dispenser for Mating...

Mating disruption is used to manage Amyelois transitella (Walker) (Lepidoptera: Pyralidae). Current mating disruption uses a single compound, but at least one other is necessary for source contact in laboratory assays and efficient capture in traps in the field. We conducted experiments to examine disruption of sexual communication and attraction of males to these high-rate dispensers with either one or both compounds. Trap suppression experiments compared males captured in pheromone traps in orchard blocks treated at a low, medium, or high number of dispensers per ha, and a trapping study used the dispensers as attractants in sticky traps to compare their relative attractiveness. The 2-compound dispensers suppressed male capture in pheromone traps more effectively than the 1-compound dispensers at the intermediate density. The trapping study found that both dispensers captured fewer males than a monitoring lure in the absence of mating disruption but more males in the presence of mating disruption. These data provide additional support for a hybrid mechanism of mating disruption for this species and indicate that the use of the more attractive 2-compound dispensers could make mating disruption more effective at the lowest dispenser density currently used. Alternatively, a lure base on the 2-compound dispenser could provide equally effective monitoring in the presence of mating disruption.