1a. Objectives (from AD-416)
The overall objective is to improve the sustainability of apple, pear, and walnut cropping systems in the western U.S., by developing knowledge and tools that would allow growers to take full advantage of biological control in their orchards.
1b. Approach (from AD-416)
• Objective 1: Evaluate the sublethal effects of newer pesticides on key natural enemies in laboratory assays, and in apple, pear, and walnut orchards • Objective 2: Characterize the phenology of key natural enemies using banding studies in the fall and orchard sampling during the spring and summer • Objective 3: Evaluate semiochemicals as a method of monitoring natural enemy presence, abundance, and phenology; assess effectiveness of this tool in evaluating the effects of inseticides on natural enemies; and compare sampling efficacy of these products to results of sampling done using beating trays • Objective 4: Develop methods in gut contents analysis to monitor predation of codling moth by generalist natural enemies, and confirm gut contents results using video monitoring. Documents Reimbursable agreement with Washington State University (CSREES Specialty Crops Research Initiative). Log 37158.
3. Progress Report
Enhancing biological control to stabilize western orchard IPM systems. Effects of newer pesticides on seven key natural enemies were evaluated in laboratory assays, and in apple, pear, and walnut orchard trials. The phenology of key predators and parasites of orchard insect pests, including timing of emergence from overwintering quarters, onset of entry into orchards in the spring, and development of spring and summer generations was determined. Natural enemy presence, abundance, and phenology was monitored. Gut contents analysis methods were developed to monitor predation of codling moth by generalist predators and parasites. Gut contents results were confirmed using video monitoring. Economic analyses were conducted to determine the long-term costs associated with IPM programs with and without various levels of biological control. Clientele were surveyed to identify optimal ways for presenting information that will lead to quicker adoption of new technologies and synthesize existing and new information to provide real-time support for pest control decisions by growers and pest managers. Early bioassays with two natural enemies indicate that new insecticides targeting ryanodine receptors did not affect beneficial insects. Emergence studies showed predators leave overwintering sites from mid April to late May. Natural enemy trapping studies showed two chemicals are potent attractants of an important lacewing species. Emergence and phenology studies showed that the third generation of the predator D. brevis coincides with the second generation of codling moth, putting this predator at risk when insecticides are used to control codling moth. Video observations of sentinel codling moth cocoons showed that vertebrate predators such as birds account for most predation. A new codling moth DNA detection protocol from predator homogenates has proven to be robust and broadly applicable for predator gut content studies. Identification of vulnerability periods of natural enemies will allow modification of pesticide programs to conserve beneficial arthropods. Attractants allowing monitoring of presence and abundance of beneficial insects will promote more cautious pesticide use by fruit growers. New DNA-based forensic studies will enhance throughput of predator gut content analysis. ADODR Statement: Monitoring of activities and progress on this project was accomplished by direct supervision of on-site employees, and use of email and telephone to communicate with off-site collaborators.