Cures for Worms Eating My Orange Tree

• Bagworms are perennial insects found throughout the U.S. They get their name from the silky, bag-like cocoon they construct to wrap themselves, which they take with them wherever they go. Bagworms eat leaves and stems of ornamentals, woody trees and fruit trees, including orange trees. Large concentrations of worms can eliminate most of a tree's foliage, leaving it nearly bare. Controlling bagworms at the larvae stage before worms mature into caterpillars and multiple is the best way to protect your orange trees.

Hand Remove Cocoons from Trees

• In the spring, wind transports bagworms to trees in order to feed. Yet when they sense danger, larvae retreat to their cocoon and hide-out until the threat is gone. It's during this time of the year--early to mid-spring--when you can generally find holes in orange tree leaves or cocoons on trees. Manually pluck as many cocoons as possible from trees and destroy them. This is the best way to control the bagworm infestation, especially if only a small number of cocoons are present. Handpicking, however, may be unrealistic if infestation is significant.

Apply a Biological Control

• Bacillus thuringiensis (Bt) is a biological control cure that rids large bagworm populations from orange trees. When bagworms come in contact with Bt after it has been applied to orange trees, the worms become sick and die. For best results, the University of Missouri recommends treating orange trees with Bt in mid-to late-May through mid-June as this is usually the time when bagworms are hatching and feeding.

Use an Insecticide

• Permethrin is a general purpose insecticide that is an effective chemical control for eliminating bagworms from orange trees, states Do-It-Yourself Pest Control. The product is sold as a spray that you apply to orange trees in the late-spring or early-summer ideally in June or July before the bagworm population takes over your orange trees. According to the University of Nebraska-Lincoln, do not bother spraying an insecticide on bagworms in August or the fall as a chemical control method is basically useless when the worms are mature adults.