How do you distinguish webs of eastern tent caterpillar versus fall webworm?

• A. The eastern tent caterpillar makes webs in a tree crotch, while the webworm makes webs over leaves and ends of branches.
• B. The eastern tent caterpillar makes webs in a tree crown; fall webworm makes webs on the ground.
• C. Both species build webs only in the trunk.
• D. Webbing is not produced by any caterpillars.

Answer: (A)

The main way to tell them apart is by where the silk is built and when it’s found. Eastern tent caterpillars create a silk tent inside a tree crotch or fork in early spring, typically high in the canopy. Fall webworm builds large, white, cottony webs around the ends of branches, enclosing a cluster of leaves, and this occurs later in the growing season, in summer to fall. So, look for a tent in a fork in spring versus a loose, leaf-packed web at branch tips in late summer. The other descriptions don’t match how these pests behave: webbing isn’t formed on the ground, isn’t confined to the trunk, and both species do produce silk webs.