1a. Objectives (from AD-416)
Evaluate the efficacy of mating disruption delivered by puffers, targeting navel orangeworm infesting walnuts in Butte, Glenn, and Tehama counties. As part of this effort, determine the baseline populations of navel orangeworm in selected orchard blocks and the efficacy of current sanitation and/or other cultural practices.
1b. Approach (from AD-416)
Currently, there are 600 acres of walnuts participating in a mating disruption program targeting codling moth (Cydia pomonella) and an additional 200-400 acres will be added this year. Blocks with high and low navel orangeworm pressure will be selected and optimal puffer placement and supporting treatment regimes will be determined. Damage by navel orangeworm throughout the growing season will be monitored. Baseline studies to determine the level of sanitation will be performed in these orchards and the relationship between walnut sanitation and navel orangeworm infestation quantified. Populations will be monitored throughout the study using virgin-baited female traps provided by ARS. Growers, PCAs, and farm advisors will be trained in proper puffer installation, monitoring protocols for traps, lures, and canopy counts. Data will be pooled from the puffer demonstrations and emailed to participants on a timely basis. Documents SCA with U C Extension, Yuba City.
3. Progress Report
This research contributes to objective 1 of the in-house project. The goal of this project is to evaluate mating disruption to control navel orangeworm (NOW) in walnuts. One ARS entomologist based in Parlier, CA is collaborating with one UCCE researcher based in Yuba City and one UC entomologist at UC Berkeley to evaluate this technique in the Sacramento Valley. The pheromone, which disrupts mating of navel orangeworm, is dispensed by aerosol puffers in walnuts, as an adjunct to the existing demonstration of mating disruption in walnuts targeting codling moth. Demonstration sites were selected in cooperation with 14 growers and their Pest Control Advisers, covering more than 2,000 acres. This new technology will be expanded to 5,000 acres in the coming year. Supporting studies assessed NOW larval survival in unharvested almonds and walnuts over the winter will develop more accurate monitoring techniques so that the use of puffers could be refined. Additional studies were conducted to document the area affected by each aerosol puffer to enhance control. Cooperator activity was monitored by reports at a stakeholder meeting in August, oral presentations at the annual meeting of the Walnut Board of California, telephone conversations and e-mail.