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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Research Project #446053

Research Project: Best Practices for Releasing Lacewings in Apples

Location: Temperate Tree Fruit and Vegetable Research

Project Number: 2092-22430-003-061-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Jun 1, 2024
End Date: May 31, 2025

Objective:
Research: 1. Determine which method of releasing lacewings results in the greatest establishment and pest control. 2. Determine which lacewing release rate is most effective for aphid control. 3. Determine the effects of organic fire blight pesticides on insectary reared lacewings.

Approach:
1a. Release insectary recommended rates of two lacewing species (Chrysoperla rufilabris and Chrysoperla carnea) as sprinkled eggs, eggs glued on cards, and as sprinkled larvae (C. rufilabris only) and compare to a no-release control in three commercial apple orchards. Treatments will be compared based on pest levels (aphids and mealybugs) and for recovery of released lacewings. 1b. For each year of the project, five blocks of commercial apples will be divided into thirds, each third receiving one treatment: drone release, ground release, or no release. The grower will select the release rate, timing, etc., and conduct drone releases. The research team will do the ground releases and insect counts to determine lacewing recovery rates and pest levels. 2. Four release rates of lacewings from the most effective method in 1a will be compared to a no-release control for pest control and cost. 3a. Lab assays will assess all available organic flight blight pesticides for direct contact toxicity to purchased C. rufilabris and C. carnea (eggs and larvae) compared to a water control. We will assess larval mortality and egg hatch. Surviving larvae will be monitored using motion tracking software (Ethovision) for 30 minutes, measuring distance travelled and angular velocity. We will also assess the prey consumption rate of surviving larvae. 3b. Single trees at a research orchard will be treated with organic fire blight products using a backpack sprayer. Trees will be treated at different times so that 0, 3, 7, and 14 day-old residues of each pesticide are simultaneously available. We will make leaf disk arenas, on which a single lacewing egg or larvae of each species will be placed and then assess larval mortality/egg hatch. Captured lacewings in Obj. 1-2 will also undergo molecular gut content analysis to determine if they are effective predators of orchard pests and the degree to which they are intraguild predators of resident natural enemies.