Developing best practices for releasing lacewings in apples

Project Overview

Project Type: Research and Education
Funds awarded in 2024: $350,000.00
Projected End Date: 03/31/2027
Grant Recipient: USDA-ARS
Region: Western
State: Washington
Principal Investigator:
Tianna DuPont
Washington State University Extension


  • Fruits: apples


  • Pest Management: biological control

    Proposal abstract:

    Two men talking in the middle of an apple orchard row, with trees on either side. A drone flies overhead.
    Releasing by drone

    Washington apple growers are experimenting with releasing natural
    enemies purchased from commercial insectaries. Lacewings
    releases, targeting aphids and mealybugs, are the most common.
    Aphid and mealybug organic control options are limited and damage
    from honeydew production alone can cause $400-$4,000/acre of
    yield loss. ≥25% of growers are conducting releases, spending
    $153/acre/year. The industry purchases $1M of natural enemies per
    year, with demand increasing annually, especially for releases by
    drone. Growers’ indicate that their biggest barrier to successful
    adoption is lack of best practice recommendations, not cost or
    perceived lack of efficacy. However, current recommendations are
    based on greenhouse use and are not well-matched to orchards,
    which greatly differ in climate, acreage, crop, and target pests.
    Therefore, this project addresses a need for scientifically-based
    recommendations on how to release lacewings in apple orchards. We
    will determine (1a) which release methods provide the most
    effective aphid and mealybug control by comparing life stages
    (releasing eggs or larvae), available species, and methods
    (sprinkled or hanging egg cards). We will compare the efficacy of
    the two commercially available species of lacewing,
    Chrysoperla rufilabris and Chrysoperla
    (sold as “C. carnea”). We will conduct
    large plot tests of drone-released lacewings to determine (1b) if
    they are effective and to what extent release rates need to be
    increased for success compared to a ground release. For the most
    effective release method, we will (2) identify the release rate
    that best balances cost and pest control. Finally, we will (3)
    determine if and for how long residues of organic pesticides are
    harmful to lacewings, allowing for better integration of chemical
    and biocontrol tactics. To increase grower knowledge and adoption
    of release best practices, we will develop a “tailgate training
    kit” and a natural enemy releases webpage. The bilingual
    “Tailgate training kit” will be designed for managers to train
    crews, with a large flipchart and a plain language handout
    summary for in-field trainings on how to perform releases, and a
    pocket flipbook on identification and other key information for
    later reference. The natural enemy releases “how-to” webpage will
    host summaries of research findings, best practice
    recommendations, and four video tutorials on how to conduct
    releases (ground and drone), do quality control checks of
    lacewings received, and scout after release. A participatory
    research framework will be used to increase grower-to-grower
    information spread and adoption. Each grower-collaborator will
    host a field day, where they will discuss their experiences with
    releasing predators and where we will demonstrate release methods
    and scouting, in collaboration with insectary representatives.
    The grant team will conduct a half-day Natural Enemy Releases
    session, with a grower-collaborator panel discussion. At the end
    of the project, we will conduct a follow-up evaluation to capture
    producer adoption of new practices and the impacts on their
    farms. Increased adoption of and success with biocontrol releases
    will reduce grower expense on unsuccessful releases and decrease
    pesticide use. This will decrease harm to non-target organisms,
    pesticide environmental contamination, and farmer and community
    exposure to residues.

    Project objectives from proposal:

    Research Objectives

    1. Determine which method of releasing lacewings results
    in the greatest establishment and pest control

    a. Compare species, life stages, and cards versus loose eggs

    b. Compare drone to ground releases at orchard-scale

    2. Determine which lacewing release rate is most
    effective for aphid control

    3. Determine the effects of organic pesticides on
    insectary-reared lacewings

    a. Determine acute toxicity of organic pesticides to lacewings

    b. Determine the duration that field-aged residues remain

    Education Objectives

    1. Increase grower knowledge and adoption of natural
    enemy release best management practices

    80% of participants in trainings will gain new knowledge and 50%
    will plan to try natural enemy releases on their farms or alter
    how they are currently doing releases.

    Activity A. Create a toolkit for growers to train their workforce
    on lacewing releases

    Output: Toolkit

    Activity B. Create a web-based resource that acts as a “one-stop
    shop” for information on release best practices

    Output: Website

    Activity C. Increase grower adoption of successful lacewing
    releases using a participatory research framework

    Outputs: Advisory meetings, Field days, Intensive

    2. Disseminate research results to other agricultural
    professionals and the general scientific community

    Activity A. Scholarly outputs

    Outputs: journal articles, conference presentations

    Activity B. Additional grower and other agricultural professional

    Outputs: Fruit Matters articles, grower meeting

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.