Evaluation of Alternative Pheromone Dispensing Technologies

Development of alternative pheromone dispensers continue to show promise for disruption of long-range communication between male and female codling moths. Hollow fibers containing the codling moth pheromone that can be dispersed at 30,000-40,000 units per acre can currently be distributed by specialized application equipment affixed to either helicopters or fixed wing aircraft, whereas efforts to develop ground-based applications are underway elsewhere. The applications suppressed virtually 100% of the codling moth trap counts in 3 orchards using 2 applications of the fibers, but damage suppression was not equally dramatic. A similar result was obtained with low rates of puffer (aerosol style emitters) delivery devices. Trap suppression was easily obtained, but damage suppression did not follow. Therefore, different strategies targeting short-range location by codling moth need to be developed in conjunction with disruption of long-range disruption. Future programs will focus on multiple types of dispensers in combination to simultaneously target both long and short range orientation. A rapid means to assess a broad array of pheromone dispensers was tested using the antenna of codling moth to detect pheromone emissions from a unit. Using this approach, the duration of the fibers was determined to potentially exceed 10 weeks, whereas other units (laminated flakes) emitted for shorter durations depending on the level of sunlight striking the unit. The sprayable formulations of codlemone are still not stabilized enough to avoid breakdown in sunlight with the Suterra formulation no longer being detectable within 1 week, whereas the 3M formulation was detectable at 7 days, but not 14 days. These products have been shown previously to have much longer emission rates for applications made to shaded portions of mature walnut canopies.