Whole-Farm Mating Disruption to Manage Grapholita molesta (Lepidoptera: Tortricidae) in Diversified New Jersey Orchards

Fruit orchards in New Jersey are usually isolated from neighboring farms and diversified, often containing separate plantings of peach (Prunus spp.) and apple (Malus spp.). These crops can suffer significant damage from oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae). This study evaluated the effect of managing G. molesta by using sex pheromone based mating disruption applied to both peaches and apples (whole-farm mating disruption) rather than treating either crop alone. In year 1 of the experiment, G. molesta mating disruption applied to the adjacent peach and apple blocks provided better control than treating peaches or apples alone. During year 2, treating these adjacent blocks or only treating apples controlled G. molesta equally well. G. molesta populations were so low at the end of year 2 that mating disruption was not applied against this pest during year 3. This allowed us to determine whether applying mating disruption for two consecutive years controlled G. molesta well enough that it eliminated the need mating disruption for three consecutive years. The mean cumulative number of G. molesta captured in plots where both peaches and apples had been treated did not exceed two moths per trap in the third year of this experiment. In contrast, G. molesta capture rebounded during August in peaches and apples that had not been treated with mating disruption the previous 2 yr. Implications for managing G. molesta by using mating disruption as a "whole-farm" tactic as well applying it for two consecutive years and not a third year are discussed.