Have you ever noticed dead branches or dying leaves on your trees, even when you take good care of them? You might want to check for the following bugs that eat trees, as they can silently invade and wreak havoc on your beloved foliage. Not all insects are harmful (and some are actually beneficial!) but there are a few insect pests that can cause severe damage to your tree. In this article, we will identify the most common offenders, their behaviors, and what you can do to stop them from damaging your trees.
Photo credit: Michael Bohne, USDA Forest Service, Bugwood,org
Asian Long-horned Beetle:
This invasive species originated from China and Korea and has been spotted in several parts of the United States. They prefer to munch on the leaves and bark of maple, birch, elm, and willow trees. Infested trees would have holes in their trunks and branches, and the bark would peel off easily. Adult beetles are one inch long, shiny, and black with white spots, while their larvae are white and wormlike.
What to do: Because of the invasive nature of this pest, if you spot any signs of infestation, immediately contact USDA APHIS, and do not move any material that may contain the beetle. Infested trees should be removed and destroyed to prevent the spread of the beetles.
Photo credit: Robert L. Anderson, USDA Forest Service, Bugwood.org
Eastern Tent Caterpillar:
These caterpillars weave silk tents around the branches of fruit trees, maple, and oak trees. They devour leaves and can cause the leaves to turn brown and die. Mature caterpillars are hairy and black with white stripes on their back. They usually appear in spring and can be seen crawling all over the tree.
What to do: If the infestation is small, you can remove the tents and caterpillars by hand or using a hose. Birds will make quick work of any caterpillars that fall to the ground. For larger infestations, call us for treatment, especially on sentimental or otherwise important trees in your landscape.
Photo credit: John A. Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org
Bagworms:
When it comes to bugs that eat trees, these caterpillars don’t mess around. These pests are called bagworms because they build protective “bags” made of leaves, twigs, and silk, which they carry around with them as they move, even when they eat. They feed on junipers, evergreens, and fruit trees. Extreme infestations can cause the tree to die.
What to do: Handpick the bags and destroy them before the larvae can emerge. For severe infestations, call us for treatment, especially on important specimens like privacy screens.
Photo credit: James Solomon, USDA Forest Service, Bugwood.org
Aphids and Scale Insects:
These small, soft-bodied insects feed on the sap of trees and excrete a sweet, sticky substance called honeydew. A large infestation can cover leaves and branches with honeydew, leading to the growth of sooty mold that can damage leaves. They attack many types of trees, such as oak, maple, and fruit trees.
What to do: Prevention is the best policy with these insects, especially as honeydew can be a huge nuisance to homeowners and businesses. RTEC offers an aphid and scale control program, including preventative and suppressive measures.
Photo credit: Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org
Japanese Beetle:
This invasive species can cause severe damage to trees. The Japanese beetle feeds on the foliage, flowers, and fruits of several types of trees. In addition to causing skeletonized foliage and defoliation, they can also weaken the tree and make it more susceptible to other pests and diseases.
What to do: Remove any visible beetles carefully and put them in a jar full of soapy water. For severe infestations, contact your arborist for help, especially on trees that are aesthetically important to your landscape.
Photo credit: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org
Spotted Lanternfly:
This destructive invasive pest is a relatively newer issue but is rapidly becoming a significant threat to trees in our area. This pest can cause serious damage to trees, shrubs, and other plants. They prefer Tree of Heaven (Ailanthus altissima) as a host, but will happily feed on other hosts, including many species of hardwood trees. They can cause significant damage to agricultural, forested, and residential areas by defoliating plants and stunting growth.
What to do: If you spot these pests on your property, follow the instructions provided by USDA APHIS to report the sighting immediately. Instructions are also available for trapping these pests on the APHIS website. Many residents in areas that have been severely affected already have been trapping adult spotted lanternflies in bottles and then destroying them.
Protecting against bugs that eat trees requires careful observation, prompt action, and proper treatment. Early detection of an infestation is essential to prevent the spread of the insects and limit the damage caused to the tree. The best way to prevent insect infestations is to invest in a Canopy Protection Program. This program allows our experts multiple opportunities to prevent infestation, identify signs of insect presence, treat for common pest problems, and recommend intensive treatments as needed. This is, by far, the best way to keep your trees healthy, vibrant, and thriving for years to come.
