Worms hanging from trees can be very upsetting to homeowners. People sometimes walk into unexpected strands of silk hanging from trees, or find they worms that have fallen from trees on their clothing or cars. Besides the fact that worms in trees are a nuisance, they may cause extensive damage and defoliation of trees. Most insects that appear to be worms hanging from trees are actually caterpillars or larvae.
Oak Leaf Rollers
Oak leaf rollers are small caterpillars usually found in oak trees. When infestation is severe, oak leaf rollers may wrap silk around an entire tree. These pests can defoliate entire trees and can cause severe damage that can't be reversed. They usually feed on early spring leaf growth and may eat all the leaves on the tree. Homeowners find them annoying because they dangle from silk strands. There may be hundreds of these insects dangling from a tree.
Little bags hidden in tree trunks may be home to thousands of bagworm eggs. Bagworm larvae infest both evergreen and deciduous trees. They can affect a variety of trees, including red cedar, elm, birch and pine. Larvae emerging from these bags are black. They spin downward on silk strands hanging from trees, looking for a host plant. Many of these larvae are carried by the wind to nearby plants. If you notice bags hanging from trees, cut them down using garden shears and destroy them.
Cankerworms are also known as inchworms. There are many different species of these worms, and they infest a wide variety of trees including maple, beech, elm, apple and oak. Larvae feed on young leaves, and large populations of inchworms can defoliate entire trees. They may spin downward on strands of silk, dropping on people, picnic tables and automobiles. Insecticides are most effective after eggs have hatched and when larvae are small, according to the University of Rhode Island.
Controlling Worm Infestations
In some cases, eliminating worm infestations may be necessary in order to save a tree or group of trees. When you see egg sacs in trees, remove and destroy them in order to reduce or prevent reproduction. Chemical products intended to kill worms or caterpillars may be an effective method of control. Attracting birds can help to control worm and caterpillar populations, too. If infestations are severe, it may be necessary to call in a pest control professional to identify the species and plan a control strategy.