Worms in Cherries

Asked June 7, 2018, 6:33 AM EDT

Hi - I live in Beaverton, Oregon and just discovered that many of the cherries we have (on our backyard tree) contain little white worms hence practically speaking we can't consume any cherries from the tree and the tree is loaded with fruit. Can you kindly suggest, how can we remediate this problem? A picture of a fruit is attached herewith. Thanks, Jas

Washington County Oregon

1 Response

Cherry fruits may be attacked by two different kinds of flies: The Western Cherry Fruit Fly and the much smaller Spotted Wing Drosophila. These insects are most likely the larvae (youngsters) of the cherry fruit fly, Rhagoletis indifferens.

This year’s crop is a loss but you can decrease the infestation rate in coming years. Doing so requires a combination of strategies. These larvae are nearly ready to drop to the soil where they will continue their life cycle until the adult flies emerge next year. So, sanitation is key to decreasing next season’s population. Right now, begin to remove infested fruit from the tree and the ground, then bag in plastic and discard in the trash. Next year, you must also spray.

See “The Western Cherry Fruit Fly and Your Backyard Cherry Tree” for further details: http://cru.cahe.wsu.edu/CEPublications/FS125E/FS125E.pdf. It’s written from the perspective that home gardeners must help protect commercial crops in Washington state. Even so, the management principles and sprays also pertain to home gardeners here in Oregon.

Our official insect management handbook states: “Home orchardists: Grow early-maturing varieties such as 'Chelan.' Pick fruit within 8 to 9 days of catching the first flies, which will happen before egg hatch. Remove all fruit from the trees to eliminate sites for the fly to reproduce. Cultivation of the soil has not been effective, as the pupae are very hard-shelled.”