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Pear psylla phenology model is now live on DAS

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Written by Louis Nottingham, WSU Entomology, and Liesl Oeller, WSU Decision Aide System, March 31, 2022

The new pear psylla phenology model is now live on DAS (! You can follow pear psylla degree days and corresponding development curves, which are updated daily for all of your weather stations. Additionally, the DAS page will display management guidelines for key phenology timings for psylla, mites, mealybug, scale, codling moth, and more.

*In order to access this model, go to “my stations” and add the pear psylla model to each of your stations.

A promotional version with degree days updated weekly for 7 weather stations and full season recommendations can be found on the Tree Fruit Extension website in the Pear IPM section: Please send feedback to Louis Nottingham.


Louis Nottingham

Washington State University, TFREC



Liesl Oeller

Liesl Oeller

Washington State University, DAS

Funding and acknowledgments

The degree day model was completed by Dr. Vince Jones, WSU, in 2019 with funding from the Washington Tree Fruit Research Commission and Fresh and Processed Pear Committees. Guidelines were developed by the collaborative work of the WSU pear IPM research and Extension team lead by Dr. Louis Nottingham, Dr. Robert Orpet, and Tianna DuPont, funded by grants from the Fresh and Processed Pear Committees and WSDA Specialty Crop Block Grant program. DAS web development and support are provided by the DAS team: Dr. David Crowder (Director), Stefano Borghi, Matt Brousil, Liesl Oeller, and Javier Gutierrez Illan.

Additional information

Visit the Pear IPM webpage on the Tree Fruit Extension Website to learn more about pear psylla, its natural enemies, full season management, and local scouting information for Wenatchee, WA (

Subscribe to the WSU Tree Fruit Decision Aid System for real-time updates of pest and disease models at your orchard locations across WA state

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