Eastern Tent Caterpillars & Fall Webworms: Not to Worry
Eastern Tent Caterpillars & Fall Webworms
Have you ever wondered about these silky masses that appear on tree branches? Maybe you’ve poked them with a stick and seen hundreds of little caterpillars huddled up in there? Homeowners are often deeply concerned when they notice them in their trees however they are not usually a true threat to tree health.
If you’re noticing these “webs” or” tents” in early Spring in the crotches of branches, they are probably from Eastern Tent Caterpillars. If you’re noticing them in late Summer/early Fall at the tips of branches, they’re more likely from Fall Webworm. These are are 2 different species but they both feed on the leaves of trees before becoming moths.
Trees need leaves for photosynthesis, of course, but the amount of leaves that these caterpillars eat is almost never enough to kill a tree. These bugs usually only eat about 10-15% of the leaves either in early in spring (these leaves will grow back in summer) or in late summer (these leaves were about to fall off anyway). A truly healthy, well-established tree can even withstand full defoliation for at least 1-2 years without worry. The only trees that may be at risk are very young and/or newly transplanted trees that are covered and already have compounding health issues.
So what do we recommend homeowners do about these bugs?
Nothing! This is a great option if you don’t mind how they look. Your trees will likely be fine.
Install and maintain birdhouses. They’re natural predators and they eat hundreds of bugs a day.
Manually remove tents. Do not prune the branches, just break and destroy the silky nests.
As a last resort, contact us for an organic spray application. This will kill the bugs but you’ll still have some empty webs hanging in trees.