Problem with a Sweetheart cherry tree
Greetings, In the fall of 2017, we planted two cherry trees, a Rainier and a Sweetheart, in our Bend garden. This past summer, the Sweetheart had black aphids. We pruned off the affected foliage and killed as many aphids as possible in a bucket of soapy water. The cherries looked ok, but virtually all of them had a small hole near the stem, and tiny white worms (larvae?) inside. Are these two different problems? How can I treat the tree to prevent this from happening this year? We also have honeybees, so I need to be careful about using pesticides. The Rainier cherry is located about 30 feet away, and did not have any problems at all. Thank you for your suggestions. Sincerely, Mariann Gorman
Deschutes County Oregon
If you have a white "worm" or larva in the fruit, this is going to be different than an aphid. The pest in the fruit is likely Western Cherry Fruit Fly more info here: https://pnwhandbooks.org/insect/tree-fruit/cherry/cherry-western-cherry-fruit-fly
You can use yellow sticky traps to monitor for the fruit fly so you know when to spray if your are going to spray for management.
The aphids were likely Black Cherry aphids, more info here: https://pnwhandbooks.org/insect/tree-fruit/cherry/cherry-black-cherry-aphid The one type of chemical control that can be used for both pests is something that has the active ingredients pyrethrins, but you would want to spray according to the labels to avoid non-target insects.