Wormy apples

Codling moth larvae cause wormy apples and pears.

Click here to watch a video on making home-made traps for Codling Moths.

Chemical Control

Spraying apple and pear trees to control codling moths should start about June 6 in the Uintah Basin. Sprays will need to be applied periodically to protect fruit until September 1. If some damage can be tolerated, trees can be sprayed during the first and third weeks of June and then about July 1 and August 1.

Chemical Sprays to Control Codling Moth in Home Orchards
Chemical Examples of Brand Names

Spray Frequency

carbaryl Sevin, Bonide Fruit Tree Spray  10-14 days May thin apples if sprayed in June
malathion Malathion  7-10 days  
esfenvalerate Ortho Bug-B-Gone  2-3 weeks repeated use may increase mites
permethrin Bayer Advanced Dust 10-14 days repeated use may increase mites
pyrethrin Concern Multi-Purpose  7-10 days repeated use may increase mites
spinosad Green Light, Monterey Garden Insect Spray 10-14 days some formulations are approved for orgnanic production
acetamiprid Ortho Flower, Fruit and Vegetable Insect Killer Concentrate 14-21 days don't use more than 4 times per year
 Always read and follow label directions.

Bagging Fruit

Good control can be achieved by enclosing young fruit in bags right on the tree to protect them from the codling moth. This is the only nonchemical control method that is effective. However, it is quite time consuming to apply the bags so this method is most manageable on smaller trees with fewer fruit. You may bag all the fruit on the tree or just as many fruit as you think you will need. Keep in mind that any unbagged fruit is likely to serve as a host and increase the pest population so it would be prudent to employ sanitation and mass trapping to keep the population in check.

Bagging should be done about 4 to 6 weeks after bloom when the fruit is from 1/2 to 1 inch in diameter. You may want to apply a chemical spray in June to protect fruit until it is large enough to bag. Prepare small bags by cutting a 2-inch slit in the bottom fold of each bag. Thin the fruit to one per cluster. Slip the thinned fruit through the 2-inch slit so that it forms a seal around the stem and staple the open end shut.

This technique won't affect the maturity or quality of the fruit, but it will prevent full color development on red varieties. You'll need to open some bags to check for ripeness after September 15 to allow for color developmet. Other benefits to bagging include protection from sunburn and larger fruit as a result of diligent thinning.

Click here to see an image of the fruit bagging technique.