How to avoid worms in cherry tree?

Asked May 18, 2020, 3:58 PM EDT

Hello. I live in Portland. We have a cherry tree. It is relatively young (maybe seven years old), is about 25 feet tall, and has a bunch of cherries (still mostly green). I heard that we need to spray it to keep worms out of the cherries. But I am concerned about the health of bees and other "good" insects as well as spraying poison in my yard. How do we treat the cherry tree so as to avoid worms in the cherries? Thanks, ---Robert V.

Washington County Oregon

1 Response

Hi Robert,

Dilemmas! Cherries do attract two insects that lay their eggs in developing cherries - the western cherry fruit fly (Rhagoletis indifferens) and the spotted wing drosophila (Drosophila suzukii). Managing these pests with insecticides is certainly feasible, but its intensive and it will likely impact beneficial insects. Fortunately, treatments after occur after cherries blossom, so the impact to bees is minimal - the caveat being is that the insecticide treatments don't drift onto blooming bee-attractive weeds or plants in the drift zone. Applying insecticides as bee activity is reduced (i.e., close to dusk) can also help minimize exposure, but some products can remain active on the plant surface for many days (others will break down overnight). We would recommend exploring non-chemical options for backyard trees and monitoring the situation. For options, check the two links below:
https://pnwhandbooks.org/insect/emerging-pest-spotted-wing-drosophila-berry-stone-fruit-pest
https://pnwhandbooks.org/insect/tree-fruit/cherry/cherry-western-cherry-fruit-fly
Good luck - here is to a delicious bowl of worm-free cherries this summer!