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New Phenology Based Psylla Management

March 1, 2022

Pear Psylla Phenology IPM Guide will help manage pear psylla using the new degree day model!

As temperatures warm and the snow melts, it is time to think about pear psylla management. In warmer areas like Oregon and southern Washington, psylla are already back in the orchards and laying eggs. In central and northern WA, psylla will move into orchards once the snow melts.

IPM strategies for pear psylla provide optimal season-long control by utilizing selective sprays and cultural strategies to suppress psylla while conserving natural enemies. If you have ever wondered why psylla control falls off toward the end of the season, it is likely due to a lack of natural enemies from too many broad-spectrum sprays. This is why we encourage the use of selective management approaches, such as kaolin clay, insect growth regulators (IGRs), organic insecticides, and cultural techniques like tree washing and summer pruning.

In order to help you choose the right approach for your orchard and better understand the development of pear psylla in your region, WSU has created a pear psylla degree day model and associated management strategies. Visit the new page Phenology Based Pear Psylla Integrated Pest Management for the model and strategies. The website is a work in progress and subject to change as we continue to perform experiments and refine the conventional and organic management strategies.

Leafhopper Deterrence Linked to X Disease Management

two people walk between rows of cherry trees on white reflective fabric covering the orchard floor

March 10, 2021

Leafhopper Deterrence Linked to X Disease Management

WSU entomologists and industry partners learn about X disease vectors to help the cherry industry optimize management. Work by the Nottingham lab on insecticide efficacy (“catching lots of wild leafhoppers and trying to keep them alive long enough to kill them”) and systemic insecticides applied via soil drench is highlighted.

Prebloom Management of Pear Psylla with Particle Film

February 8, 2021

Psylla will soon be on the move!

Louis Nottingham and Robert Orpet wrote an article in the February 2021 edition of ‘Tree Fruit News’ reminding growers to start preparing dormant sprays of kaolin clay (Surround) to deter pear psylla colonization in the orchard. A dormant Surround spray will provide the first line of defense to keep psylla from entering your orchard. The optimal time to make this first Surround application depends on weather, but here is a good rule of thumb: if it is warm and dry enough for you to safely spray, go for it – psylla are probably colonizing your orchard!

Click the pic to learn more.

closeup of two pear buds in the orchard
Picture taken on 3/24/20 of a pear bud just before burst, sprayed at dormant (3/16/20) with Surround CF at 50 pounds/acre. This bud remains protected against oviposition until fresh green tissue ‘bursts’ from within the hard exterior scales.


Surround applied in the fall for pear psylla management

November 19, 2020

Orpet and Nottingham article in ‘Fruit Matter’s Newsletter’ about potential for Surround applied in the fall for pear psylla management.

Kaolin clay (Surround WP) is a white sprayable powder that discourages pear psylla from laying eggs on pear trees by creating a physical barrier over the tree’s surface. If sprayed early in the season, the white coating could also deter psylla from colonizing orchards, possibly due to repellency of reflected UV light to insects. Kaolin is more persistent on trees than most insecticides, especially when used with a spreader-sticker (check labels for compatibility and mixing instructions), and it has low risk of harming natural enemies because it is non-toxic.

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