Location: Crop Improvement and Protection Research
Project Number: 2038-22000-020-026-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Feb 1, 2025
End Date: Jan 31, 2026
Objective:
Objective 1 – Evaluate and determine best practices for mating disruption for diamondback moth management.
Objective 2 – Examine non-crop host use and dispersal of diamondback moth to support best use of mating disruption and management of insecticide resistance.
Objective 3 – Evaluate parasitism of diamondback moth by resident parasitoids to improve integration of biological control into management plans.
Objective 4 – Examine insecticide resistance in diamondback moth populations to best integrate use insecticides to promote use of alternative strategies and proactively manage insecticide resistance and an integrated pest management (IPM) framework.
Objective 5 – Extension of project results and information.
Approach:
Objective 1: Small plot trials (1/2 ac) in commercial broccoli fields will be used to assess the efficacy of different types of mating disruption products and their dispensers. Large scale trials will be used to examine the ability of mating disruption to reduce larval diamondback moth populations and damage to the crop. Trials will also test the effects of dispenser placement in the fields to identify optimal deployment strategies and support their use. The work will take place over three years.
Objective 2: Wild host plants will be surveyed during the winter and spring for diamondback moth. In both the Salinas Valley and Ventura County, non-crop hosts will be surveys for 12 weeks, with sampling occurring every two weeks. In each region, six locations will be selected for monitoring based on the abundance of non-crop brassica species that can serve as reservoirs for diamondback moth in the winter and spring. The work will take place over three years.
Objective 3: Larvae will be collected from the Salinas Valley, Ventura, and Santa Maria production areas at 3 conventional and 3 organic fields per region. For each field, larvae will be collected midway through the cropping cycle and at the end of the crop with up to 150 larvae/collection. Larvae will be sent to California Department of Food and Agriculture’s Sacramento facility and reared on collard leaves until pupation. All parasitoids that emerge from the larvae will be identified to determine the species composition of parasitoids in the environment. The work will take place over two years.
Objective 4: Some of the larvae collected from Objective 3 will be subjected to bioassays to determine the level of insecticide resistance across populations of diamondback moth collected from the three major regions. Bioassays will use several key insecticides that are used in the production regions and data will be used to inform resistance management plans.
Objective 5: Outcomes of the work will be shared with stakeholders in all three major production regions. Information will be shared at field and demonstration days, blog posts, presentations, and manuscripts.