Improved deposition and performance of a microencapsulated sex pheromone formulation for codling moth (Lepidoptera: Tortricidae) with a low volume application

Experiments were conducted to evaluate the deposition pattern and effectiveness in dis-rupting male orientation to virgin female-baited traps of a microencapsulated sex phero-mone formulation for codling moth, Cydia pomonella (L.) in apple, Malus domestica Bordhausen. The efficacy of two application techniques was evaluated in field trials with the microencapsulated formulation Checkmate ® CM-F: a high volume (926 liters per ha) application with an air blast sprayer and a low volume (46 liters per ha) applica-tion with a custom-built vertical boom sprayer. These treatments were compared to an unsprayed control and a control treatment where the formulation was applied directly on the ground within the plots. Disruption of virgin female-baited traps was significantly greater in the low volume versus the air blast application and versus the two types of control plots. Levels of disruption in the air blast-sprayed plots were not different from untreated plots or in plots where the sprayable sex pheromone was applied directly on the ground. A significant increase in the proportion of traps catching moths occurred in week 4. A significant interaction occurred among the effects of spray method, tree can-opy position, and leaf surface on microcapsule deposition. This interaction was likely due to the low rate of deposition of microcapsules on the undersides of leaves in the lower canopy with the low volume sprayer. The low volume sprayer deposited signifi-cantly more microcapsules in the upper canopy than the air blast sprayer. Significantly more microcapsules were deposited on the underside versus the top of leaves in the up-per canopy with the air blast but not with the low volume sprayer. Key Words: sex pheromone, mating disruption, apple, pest managemen