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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Research Project #439378

Research Project: New Tools for Improving Biological Control of Pear Psylla by Trechnites Parasitoids

Location: Temperate Tree Fruit and Vegetable Research

Project Number: 2092-22430-003-008-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Oct 1, 2020
End Date: Sep 29, 2023

Our project will improve biocontrol of pear psylla by increasing understanding of one of its key natural enemies, the parasitoid Trechnites isidiosus. Objective 1: Develop a grower tool to estimate parasitism levels based on adult Trechnites trap capture and pear psylla populations. Objective 2: Determine the diversity of Trechnites spp. parasitoids in the U.S. Objective 3: Determine the role of pear psylla honeydew volatiles in Trechnites attraction to their hosts.

Use lab assays to experimentally determine how accurately dissection can detect small stages of Trechnites by allowing Trechnites to oviposit into pear pasylla, dissecting those psylla, and conducting PCR on dissected psylla. Monitor adult Trechnites trap catch, pear psylla nymph age distribution, percent parasitism in 12 locations in WA and OR and use adult trap catch. Use this data and weather station data to create a model allowing prediction of percent parasitism based on Trechnites and psylla abundance. Monitor Trechnites populations in WA and OR pear, pear in other parts of the US, and near native willows to determine if multiple species/morphotypes are present. Use lab assays to determine if Trechnites is attracted to pear psylla honeydew. Then, collect and identify honeydew volatiles to make a synthetic volatile blend.