It’s easy to mistake an eastern tent caterpillar for a moth, especially since this type of caterpillar is from the moth family. The scientific name is Malacosoma americanum, and they are pests that are native to North America. Eastern tent caterpillars can be a nuisance because their nests are eyesores and they can defoliate a tree when in high numbers. If you’ve been noticing a lot of moth-like creatures around the home lately, it’s worth the effort to determine whether they are eastern tent caterpillars or something else.

What Makes Eastern Tent Caterpillars a Nuisance?

There are fluctuations in the population of eastern tent caterpillars, and they vary from region to region. These pests become a nuisance in the spring months when there is little foliage on the trees and they can build nests and crawl around leaves and plants. Eastern tent caterpillars are most commonly found on wild cherry, apple and crabapple trees, but they can be found on many other types of trees, including peach, pear and plum trees.

If eastern tent caterpillars travel in large numbers, they can defoliate a tree and build plenty of silken nests that are found in the limbs of the trees. The larvae are almost more of an eyesore than the nests because they can be found crawling around trees and plants, and they become vulnerable to being squashed on sidewalks and streets, leaving behind more mess. Having eastern tent caterpillars around the home is not fun, and they can quickly become a headache for the average homeowner.

How Do I Know that I’m Dealing with Eastern Tent Caterpillars?

One of the telltale signs that you’re dealing with eastern tent caterpillars is that the activity is occurring in the spring, as opposed to the fall like with webworms. The nests can be rather large, and they are found in the crevices of the limbs of trees. Looking closely, there will be egg masses that contain up to 400 eggs! These sacs are covered with a black varnish and encircle very thin branches.

When the caterpillars begin to hatch, it’s early spring, around March. Eastern tent caterpillars are very social creatures, so you’ll notice them staying together and building nests. The larvae look very similar to baby caterpillars; they’re hairy and are black with stripes. It takes about 4 to 6 weeks for the caterpillar mature, and at this point, the caterpillars will wander away from the nest where they have been living and find a private area to spin a cocoon. About 3 weeks later, an adult eastern tent caterpillar emerges, and what you see is a moth that has pale stripes and reddish-brown color.

What Can I Do if My Trees are Infested with Eastern Tent Caterpillars?

It’s always best to call in a professional arborist who can advise you on the best steps to take. First, you want to be able to verify what type of pest is in your trees, and second, you want to apply the correct treatment. The good news is that there are proactive steps you can take to avoid the risk of eastern tent caterpillars taking over your trees.

If you find egg masses in the trees, remove them by hand. The key is to look for egg masses in the winter when they begin to creep up. Checking for them in the spring will be too late; although you can still remove the egg masses if you find them. There are also natural occurrences that control the population such as other insects and moth diseases. If you find that large nests have been built around the branches, remove them and prune the tree for better health. Do not burn out the nests as some people may suggest, as you can damage your tree.