Skip to main content Skip to navigation

Research Topics

Our lab develops IPM strategies for pests of treefruit. Currently, we are focusing on pear psylla (pears), leafhoppers (cherry) and spotted wing drosophila (cherry).

Pear Psylla IPM

Pear psylla is a pest of pears (duh) that has plagued the PNW industry since its introduction to the state around 70 years ago. There has never been a lasting effective solution for this pest.  Psylla generate honeydew that drips onto fruit and leaves, culling fruit and suffocating leaves. Managing this pest is the primary charge of our lab. Find more info on pear psylla and pear IPM here: 

Cherry Leafhoppers and X-Disease

Many leafhoppers are found in orchards and vineyards. Although, direct feeding injury is of low consequence, some species vector a phytoplasma born disease known simply as X-disease.  This disease is similar to other “litter cherry” diseases caused by viruses vectored by mealybugs. Immediate symptoms are small, off-color and bitter tasting cherries, but eventually the disease will kill the tree.  This is a very new issue to Washington and there has been almost no previous research on the leafhopper species that vector X disease. More information on x-disease and leafhoppers can be found here:

Spotted Wing Drosophila

Photo by E. H. Beers

Spotted wing drosophila (SWD) is a worldwide pest of soft fruits; in Washington Tree Fruit, cherries are the primary target. The adults invade orchards and lay eggs in the fruit. What makes this pest uniquely dangerous is its ability to oviposit in ripening fruit (as opposed to ripe or overripe fruit like more drosophilids), possible due to it’s serrated ovipositor.  Little is known about where this pests overwinterers and non-crop hosts it uses. Our lab is using next generation sequencing and gut content analysis and determine what non-crop plants are important hosts in Washington. More information can be found here:



  • Developing a phenology-based recommendation program for pear psylla. 2020 – 2023. WSDA Specialty Crop Block / Washington Tree Fruit Research Commission. Co-PI: Vince Jones, Robert Orpet, Matt Jones
  • Insecticidal control of leafhoppers in cherries. 2020 – 2022. WA Tree Fruit Research Commission – Cherry . Co-PI: Tobin Northfield
  • Deep sequencing SWD gut contents to reveal non-crop alternative host plants. 2020 – 2022. BIOAg, WSU CAHNRS, Co-PIs: Robert Orpet, WSU and W. Rodney Cooper, USDA
  • Expanding the IPM toolbox for sustainable pear production. 2020 – 2022. USDA, Crop Protection and Pest Management, Co-PIs: Tianna DuPont WSU, Richard Hilton OSU.
  • Baseline resistance of pear psylla to Bexar (tolfenpyrad) and non-target effects. 2020 – 2021. WA State Commission on Pesticide Registration Co-PI: Tory Schmidt WTFRC
  • Improving pear pest management with integrated approaches. 2019 – 2022. WA Tree Fruit Research Commission – Pear. Co-PI: Elizabeth H. Beers WSU


  • Tactics to improve natural enemy releases in tree fruit (Apple and Pear) 20212023 WA Tree Fruit Research Commission (Apple), PI: Rebecca Schmidt-Jeffris, USDA ARS
  • Wigging out, then wigging in: earwig capture and augmentation for biocontrol. 2020 – 2023. Western SARE. Co-PI: Rebecca Schmidt-Jeffris, USDA ARS
  • Field evaluation of leafhopper controls for X disease management. 2020 – 2022. WA Tree Fruit Research Commission – Cherry. Lead: Tobin Northfield, WSU
  • Incorporating Trechnites into a psylla biocontrol program. 2019 – 2022.WA Tree Fruit Research Commission. Lead: Rebecca Schmidt-Jeffris USDA
  • Erythritol: an artificial sweetener with insecticidal properties. 2021. WA Tree Fruit Research Commission. Lead: William R. Cooper USDA