08/10/2026
The Sourwood tent caterpillar (Malacosoma eximia) is a native moth larva found throughout the southeastern United States. Commonly found on Sourwood trees (Oxydendrum arboreum), it may also feed on other hardwood trees, including Blackgum (Nyssa sylvatica), Sweetgum (Liquidambar styraciflua), and several species of Oak (Quercus spp.). Sourwood tent caterpillars are commonly found in dense clusters on the branches of their host trees, where they produce silken webbing that serves as shelter. The silk protects the caterpillars while they rest between feeding periods and provides some defense against predators and environmental conditions.
The silken tents are often the first sign that sourwood tent caterpillars are present. While these webs may appear unsightly, they rarely cause permanent damage to healthy, established trees. Sourwood tent caterpillars play an important role in forest ecosystems. >> Read more below amd please take a moment to make sure you have marked your weekly volunteer emails from Trees Atlanta in your email app as "not spam". Updates, news, and upcoming volunteer events may be getting hidden by your email filters!
Now... onto more about these webby nets you might be seeing in trees.
The Sourwood Tent Caterpillar: Friend or Foe?
by Chipo Tucker
The caterpillars feed on leaves for a short period during their development before pupating into moths. Most healthy trees quickly recover from the temporary loss of foliage by producing new leaves later in the season or the following spring. Their outbreaks are typically short-lived and are often controlled naturally by predators, parasites, and disease.
Sourwood tent caterpillars play an important role in forest ecosystems. They are a food source for songbirds, woodpeckers, predatory insects, spiders, and small mammals. Tiny parasitic wasps and flies also rely on these caterpillars to complete their life cycles, helping regulate caterpillar populations naturally. Once the caterpillars become adult moths, they continue to support wildlife by serving as prey for bats and other nocturnal predators. Their presence contributes to the complex food web that keeps forests healthy and diverse.
If you encounter sourwood tent caterpillars or their silken shelters, the best approach is to observe them from a distance and allow them to complete their life cycle. If caterpillar clusters are found on small ornamental trees or in areas where they become a nuisance, the affected branches can be carefully pruned and disposed of while the caterpillars are still present. The use of insecticide applications is not recommended because they can harm beneficial insects, pollinators, and other natural predators.
