Comparison of monitoring techniques in and near almonds and pistachios under mating disruption treatment for navel orangeworm

Abstract

As use of mating disruption for control of the navel orangeworm Amyelois transitella Walker (Lepidoptera: Pyralidae) in California increases, it becomes more important to find non-pheromonal attractants that perform well for monitoring both in the presence and absence of mating disruption. Accordingly, in a study running from June to mid-September we compared the performance of navel orangeworm traps baited with either phenyl propionate (PPO) or an attractive synthetic five-component kairomone blend (kairomone blend). The attractants were evaluated alone and combined with a pheromone lure in both almond and pistachio orchards that were either under navel orangeworm mating disruption treatments or in the vicinity of mating disruption. Under all tested conditions, traps baited with PPO alone and in combination with the pheromone lure (PPO-combo) captured more navel orangeworm adults than the kairomone blend alone, or, in three of the four sites, the kairomone blend with a pheromone lure (blend-combo). Traps baited with PPO alone capture more moths than traps baited with the kairomone blend alone and, under the conditions of this study, the attractiveness of both PPO and the kairomone blend were enhanced when presented with pheromone. These findings indicate that both the kairomone blend and PPO can serve for monitoring navel orangeworm in orchards under mating disruption treatments and in regions where mating disruption is common; but the more robust detection ability of PPO gives it an advantage for this application.