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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Research Project #440528

Research Project: Tactics To Improve Natural Enemy Releases In Tree Fruit

Location: Temperate Tree Fruit and Vegetable Research

Project Number: 2092-22430-003-036-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Apr 1, 2021
End Date: May 31, 2023

Objective:
1. Examine methods for increasing retention of released natural enemies. 2. Determine cost-effectiveness and efficacy of natural enemy release by drone.

Approach:
Objective 1. Examine methods for increasing retention of released natural enemies. A primary complaint from growers is that natural enemies disperse from the orchard immediately after release. Nutritional supplements such as pollen & brine shrimp cysts are commercially available and have been shown to improve retention and survival of natural enemies in greenhouses, but this has not been tested in tree fruit orchards. Using methyl salicylate lures, which attract natural enemies, in combination with nutritional supplements may further improve natural enemy retention with little additional effort on the part of the grower. We will test supplements and lures in combination and individually in plots where commercially available predators, lacewings and minute pirate bugs, have been released in both apple and pear orchards. We will collect data on pest control levels, retention of released natural enemies, and recruitment of “native” natural enemies. Objective 2. Determine cost-effectiveness and efficacy of natural enemy release by drone. One method for reducing natural enemy release labor costs is to conduct releases by drone. However, the ability of natural enemies to survive release by drone into orchards and whether this method significantly decreases natural enemy abundance relative to hand-releases is unknown. We will compare released predator abundance, pest control levels, and labor costs for releases by hand and by drone of lacewings and mealybug destroyers in apples and lacewings and minute pirate bugs in pear.