Mimosa Webworm Damage Hits Honeylocust Trees in Ohio

Honeylocust and mimosa trees in the Miami Valley and Cincinnati area are showing signs of damage due to the mimosa webworm, a caterpillar that feeds on their foliage. The damage is often mistaken for burning or scorching, but it's actually caused by the caterpillars spinning sticky webs around the tips of branches and consuming the top layer of leaves.

The mimosa webworm has three generations per year, with the third generation causing the most noticeable damage. The caterpillars are tannish brown in color and almost an inch long, and they feed on the leaflets inside their silk nests, producing black spots or frass (bug poop) as a byproduct.

This is not a fatal issue for trees, but it can be a nuisance, especially when the caterpillars start to spin down with their silk and end up in pools or other bodies of water. Homeowners may need to take action if they notice significant damage to their trees, but sprays are not usually necessary unless the tree is already stressed from another issue.