Caterpillars can be both good and bad. On one hand, caterpillars eat almost everything in sight. Large caterpillar infestations can kill trees and other plants. However, many species of caterpillar turn into moths and butterflies when they reach maturity. Butterflies spread pollen and add attractiveness to any garden. Most caterpillars can be controlled with a number of natural repellents that either remove or kill the pests from tree leaves.
Many natural and organic solutions will repel caterpillars from trees. One of the most effective methods is to wash the caterpillars out of the tree with a hose. The caterpillars can then be killed, or moved to another location. Plastic bags covered in Tanglefoot (a sticky anti-pest barrier) can be tied around the bottom of the tree during the fall to prevent some caterpillars, such as canker worms, from laying eggs in trees. Bacillus thuringiensis is a natural insecticide that can be used to kill caterpillars of all kinds. BT is sprayed on the bottom of leaves and kills caterpillars after ingestion. Other materials, such as hot pepper sauce, garlic, wax and neem oil can all be applied on tree leaves to discourage caterpillars from eating.
Many benefits can be achieved by using a natural pest remover to eliminate caterpillars. A natural repellent will not cause damage to the tree like some non-natural pesticides. Many natural repellents do not kill the caterpillar but rather encourage it to move to another location. This protects many caterpillar species from extinction and allows the caterpillars to complete their transition to moth or butterfly. Natural repellents are also safe to use around children and pets.
A few natural remedies for removing caterpillars can still be damaging to the tree or to people or pets. A few natural repellents, such as BT, are still somewhat toxic. After the caterpillar repellent has been applied, you should make sure to wash your hands right away. Do not allow children to climb into the tree until the repellent has been diluted by a rainfall.
In some cases caterpillars can be prevented from ever reaching the tree. The best way to prevent caterpillar attacks is to grow surrounding plants that do not appeal to the adult form of the caterpillar. You can also plant surrounding species of plants that are naturally resistant to caterpillar attacks. You can also plant trees that are native to your area. Usually native plants have a higher tolerance for native species of insects.
If your caterpillar infestation is severe, a natural remedy may not be enough to control the bugs, and your tree could die. Some of the natural repellents may also actually cause damage to delicate trees. If you cannot determine the best course of action, consult with a local arborist who will be able to determine what steps to take for your specific problem.