Tree Protector Against Caterpillars

Barrier Bands

• A barrier band is a strip of elastic material, usually cloth or tape tied around the trunk of a tree several feet from ground level. Usually coated with a slick substance, like organic oil, these bands prevent caterpillars from climbing up to the tree's branches. Some barrier bands, covered in a sticky chemical, traps the caterpillars later removal and elimination. Purchase barrier bands at garden supply stores or make your own at home with waterproof tape and petroleum jelly.

Burlap Sack Trap

• A simple trap constructed from a piece of string and a section of burlap material can protect trees from caterpillar infestations. Fold the burlap over itself and secure it to the tree with string or rope about five feet from the ground. Most foliage-feeding caterpillars hide during the day and emerge at night to feed. The burlap sack provides a welcoming shelter for the caterpillars as they descend from the tree in the morning. Check the traps every day, particularly during seasons of peak activity. Kill trapped caterpillars by immersing them in soapy water.

Bacterial Spray

• Bacterial spray is an alternative to chemical insecticides for controlling outbreaks of caterpillars on trees. The spray contains living cells of the Bacillus thuringiensis bacterial species, a pathogen that only affects the larvae of moths and butterflies, according to the University of Tennessee. The bacteria is fatal to caterpillars when ingested. It is effective against several common pest species, including the cabbage looper and tomato hornworm. The bacterial spray lasts about a week before it needs reapplication. It may take multiple applications to manage a large infestation of caterpillars.

Insecticide

• Some caterpillar infestations are severe enough to warrant the application of insecticides to control the outbreak. Federal, state and local laws strictly regulate the use of insecticides, particularly for domestic use. There are hefty penalties for misusing insecticide, so it is important to research all applicable regulations before purchasing these solutions. Insecticides containing chemicals like carbaryl, acephate and Malathion are effective for controlling caterpillars. Apply insecticides to tree foliage to combat an infestation or to prevent caterpillars in neighboring trees from spreading to healthy plants.