How to Get Rid of the Little White Worms in My Cherry Tree

Whether you are growing sweet or sour cherry tree varieties (Prunus spp.), it is important to monitor the trees for pests. If you find bugs inside cherries, it is likely cherry maggots, the larvae of the western cherry fruit fly (Rhagoletis spp.). There are several effective options for dealing with these pests. Depending on the species, cherry trees grow in U.S. Department of Agriculture plant hardiness zones 4 to 7.

Adult cherry fruit flies are small black bugs that are only about 1/5 inch long. They begin emerging from the soil in late May and continue to do so throughout the summer months. After five to seven days, the flies reach sexual maturity, and the females can start laying eggs. They lay the eggs inside the cherries right underneath the skin of the fruit.

After about five to eight days, the eggs hatch within the fruit. At this stage, the fruit fly is a white maggot that grows about 5/16 of an inch. They feed on the cherry for 14 to 21 days before exiting the fruit and falling to the soil to pupate over the winter before they emerge as adults the next summer.

Are there worms in cherries? Until the larvae exit the cherry, there are no external signs on the cherry fruit that a fly has laid eggs or that it is filled with larvae. For this reason, it is best to treat the fruit flies during the adult stage before they are able to lay eggs in the tree. There aren't any biological controls or natural predators that have proven to be effective in controlling these pests.

Yellow sticky panel traps can be an effective method of controlling adult cherry fruit flies. Sticky traps should be placed in the tree at least 6 feet above the ground. Make sure to remove the fruit and leaves directly around the sticky traps. One or two traps should be sufficient to control the fruit fly population but be sure to check the product label for specific instructions.

Chemical cherry worms spray is another effective method of getting rid of cherry fruit flies. There are a number of insecticides you can use to spray your tree that will be effective, such as products containing carbaryl, malathion, spinosad and pyrethrin. You will need to spray multiple times throughout the summer as adults emerge from the soil over a period of several months. If cherry fruit flies are a problem in your landscape, it is best to rotate insecticides for best results. Regardless of the insecticide you select, be sure to review the product label and follow all instructions and warnings.

In order for the adult females to lay eggs inside the cherries, the fruits need to ripen. Unripened green cherries have a hard skin that the flies cannot penetrate. As the cherries begin to ripen, check the tree frequently and harvest ripe cherries right away before the fruit flies have a chance to lay eggs. Be sure to pick up fallen fruit on the ground as well.

Mulch around the cherry tree can also help to control these pests. It can prevent the larvae from reaching the soil to pupate and makes it more difficult for adult flies to leave the soil.