Those silken webs we spot in trees such as black cherry can be a cause for alarm for gardeners. But never fear: In spring, these webs are the sign of native eastern tent caterpillars (Malacosoma americanum),who are an essential part of another, very important web–the food web!
Our native black cherry (Prunus serotina) is a primary host plant for many caterpillars, including the eastern tent. These gregarious (collectively web-building) caterpillars are often confused with fall webworms (Hyphantrie cunea) , but it’s easy to tell the difference: Eastern tents build their webs in the forks of branches in the spring, while fall webworms can be found at the tips of branches from late summer into autumn. Eastern tent larvae mature in their web, venturing out to consume foliage of trees in the Prunus tribe. (Healthy trees can withstand defoliation and should recover without intervention.) Once they are mature, they leave the tree and march forth to find a place to pupate. No longer interested in eating, these wanderers pose no threat to plants–but are a welcome source of protein for over 60 species of birds, who are often feeding their young at the time. If they’re able to avoid hungry avians, the stout, fuzzy tan/brown moth emerges in summer to lay eggs which will overwinter– if not found by predators such as beetles, parasitic wasps and of course, birds!
