Worm Free Pears And Apples

If you want worm-free apples and pears this fall, you should act now to protect them from the codling moth, a major apple and pear pest. Using insecticide sprays is probably the easiest method of preventing worms from getting into your fruit. There are also a number of other preventative steps you can take to keep worm numbers down.

• Pick up and destroy any fruit that drops prematurely from trees in June and July, since the fruit that falls is usually infested with worms. The worms will develop into new moths that will lay eggs, hatch worms and invade your crop again later in the summer.
• Place corrugated cardboard bands (2-3 inches wide) around trunks of apple and pear trees with the fluted side against the bark. This will provide a good pupation site for the insect larvae before they emerge as moths once again. Use trunk bands from late June through the early fall. Remove bands occasionally to check for the presence of fine silk webbing with worms or pupae inside, then destroy the bands and replace them.
• The best defense against worms invading your fruit is to use a registered insecticide. Based on the first activity of codling moths in the Cache Valley area and the temperatures since then, it is predicted that the first insecticide spray should be applied to apples and pears by June 1. First sprays should go on five to seven days earlier for warmer areas of Northern Utah. Check with your local county Extension agent for an update on when to spray in your area.
• Fruit will need to be protected until you pick it or until the first part of September. Reapply sprays based on the protection interval of the product you use (Imidan, 18-21 days; Diazinon, 10-14 days; Malathion, 5-7 days; Dipel or other Bt products, 3-5 days).

Diane Alston - Utah State University Extension Entomologist