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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Publications at this Location » Publication #402843

Research Project: Integrated Approach to Manage the Pest Complex on Temperate Tree Fruits

Location: Temperate Tree Fruit and Vegetable Research

Title: Seasonal activity of Trechnites insidiosus(Hymenoptera: Encyrtidae) and its host Cacopsylla pyricola (Hemiptera: Psyllidae) in pear

item Zilnik, Gabriel
item Cooper, William - Rodney
item Horton, David
item ORPET, ROBERT - Washington State University
item NOTTINGHAM, LOUIS - Washington State University
item HILTON, RICHARD - Oregon State University
item ADAMS, CHRIS - Oregon State University
item DICKENS, KATRINA - Florida Department Of Agriculture And Consumer Services
item HALBERT, SUSAN - Florida Department Of Agriculture And Consumer Services
item SNYDER, JAMES - Florida Department Of Agriculture And Consumer Services
item Schmidt, Rebecca

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2023
Publication Date: 11/7/2023
Citation: Zilnik, G.L., Cooper, W.R., Horton, D.R., Orpet, R., Nottingham, L., Hilton, R., Adams, C., Dickens, K., Halbert, S., Snyder, J., Schmidt-Jeffris, R.A. 2023. Seasonal activity of Trechnites insidiosus(Hymenoptera: Encyrtidae) and its host Cacopsylla pyricola (Hemiptera: Psyllidae) in pear. Journal of Economic Entomology. 116:1957-1968.

Interpretive Summary: Pear psylla is the major pest of commercial pear production. Trechnites insidiosus is a parasitoid wasp that was introduced as a biological control agent for pear psylla. Researchers at the USDA-ARS laboratory in Wapato, WA, Washington State University, Oregon State University, and the Florida Department of Agriculture and Consumer Services carried out a study to improve trapping methods for both species. Experiments were conducted in four research orchards over three years. The study found that 3D-printed cylinder traps and screened sticky cards were effective new tools for monitoring both species. These findings will improve monitoring tools and integrated pest management programs for pear psylla in the pacific northwest.

Technical Abstract: Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae) is the most expensive and challenging insect pest of commercial pear trees in the Pacific Northwest. Integrated pest management (IPM) programs are working toward relying more heavily on natural enemies to reduce insecticide use. Trechnites insidiosus (Crawford) (Hymenoptera: Encyrtidae) is the main parasitoid of C. pyricola, but little is known about its biology in the region. Developing sampling tools is important for the deployment of IPM programs, including monitoring of natural enemies. In this study, we examined 2 conventional monitoring methods: beat trays and yellow sticky cards, in addition to screened sticky cards and 3D-printed cylinder traps. Additionally, we tested an overwintering trap for the collection of parasitized C. pyricola. The trapping methods were tested in orchards in Oregon and Washington. Unscreened cards caught the most T. insidiosus and C. pyricola, followed by screened cards, cylinder traps, and then beat trays. Beat trays sometimes failed to catch any T. insidiosus, even when it was found in abundance via other methods. Screened cards and cylinder traps reduced bycatch and increased ease of identifying T. insidiosus. Specimens from the cylinder traps were also more suitable for use in molecular analysis. The overwintering traps were effective at capturing parasitized C. pyricola, but were highly variable year to year. The ideal trapping method will vary based on research needs (e.g., DNA preservation, reducing bycatch, catching higher numbers), but both screened sticky cards and cylinder traps were viable methods for monitoring T. insidiosus and its host.