What can we do to rid the worms from our cherries?

Asked June 26, 2013, 11:59 AM EDT

We have recently moved to Idaho and we bought a home with a sweet cherry tree. The first year the cherries were wormy so we put landscape fabric under the tree and sprayed the tree and ground with a systemic product. This year there are still worms and many cherries have more than one worm. What can we do to rid the worms from our cherries?

Canyon County Idaho insect issues gardening tree fruits horticulture

1 Response

Dear Shirley,
Unfortunately, the Western Cherry Fruit Fly is a common pest in our region. At this point in the year, the flies have already done their damage, But the good news is that you can prevent or reduce the problem next year.

From our Pacific Northwest Pest Management Handbook, I offer the following suggestions:

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. This usually occurs around the middle to end of May, or when the cherries start to turn from green to straw yellow. You can also try to remove all fruit from the trees to eliminate sites for the fly to reproduce. That is not very practical, but if you have lots of birds, they might do this for you! Cultivation of the soil has not been effective, as the pupae are very hard-shelled.

Your timing of spray, if you choose to use it, is critical. Begin spraying about May 20 to 25 and continue through harvest. Spray at 7 to 10-day intervals. Most of these products can be toxic to bees so do not spray during the day when they are active. Read and follow all label directions on all products.

The following products are labeled for use in cherries against this pest. The kaolin clay is an organic choice.
  • acetamiprid
  • carbaryl
  • esfenvalerate
  • gamma-cyhalothrin
  • imidacloprid
  • kaolin clay (Surround at Homeā„¢)-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests..
  • malathion
  • pyrethrins
- See more at: http://pnwhandbooks.org/insect/tree-fruit/cherry/cherry-western-cherry-fruit-fly#sthash.kSkEJczB.dpu...

Thank you for contacting University of Idaho Extension!