Fly Grubs in Cherries

Asked June 14, 2018, 5:47 PM EDT

I have a cherry tree in my yard of unknown variety. This year I am noticing a lot of cherries with grubs in them. The cherries often have a soft spot and a needle sized hole in the skin. The grubs are very small, about 1-2 mm long, and pale white, and until I started looking for them, they are difficult to spot. There will often be three or four grubs in an affected fruit. I'm guessing well over half the cherries on my tree are affected. I haven't seen this particular pest in previous years, and I've never sprayed any of the plants in my yard. Are these grubs likely to spread to other fruits (I have several other cherry trees, blue berry plants, apple trees, and a peach tree)? What should I do to treat the affected tree? Until I'd spotted the grubs, I was eating cherries straight off the tree. Do these grubs pose any health threat to me? Also, I tried to watch several videos from your website, but got "file not found" errors. Your responses would be helpful to me. Thank you.

Washington County Oregon insect issues cherry trees horticulture

1 Response

Two different kinds of small flies infest cherry fruits. The most likely one in your cherries is the Western Cherry Fruit Fly. The other, a smaller fly, is the Spotted Wing Fruit Fly.

“Western Cherry Fruit Fly and your backyard cherry tree” describes how you can interfere with the insect’s life cycle and annual sprays. (It’s too late to spray this year.) Because part of the life is in the soil, sanitation is important every year and is something you can start on right away: Collect and discard all windfalls. (https://s3.wp.wsu.edu/uploads/sites/2071/2013/12/Western-Cherry-Fruit-Fly-Management.pdf)

Yes, you can eat the infested cherries. Some folks do just that and consider the fruits to be protein-enriched whereas other people will pass.