webworms or tent caterpillars

Asked August 26, 2019, 2:00 PM EDT

I found a tent web in my tree in West Linn Clackamas this weekend. Someone suggested I report it as apparently it can spread. I contacted Clackamas county and they suggested I contact you. Is this something I should be concerned about?

Clackamas County Oregon

1 Response

Yes, that certainly looks like a tent caterpillar web.

General, these pests are sporadic. They seldom seriously damage a tree. The important exception is a young tree which has few leaves in the first place. A full-sized mature tree typically survives well.

You can remove the webbed growth and discard it or, if it's to high in the tree to easily reach, use a broom ha to rip apart the webbing so that birds can feast.

Stress makes a tree more susceptible to insect and disease attack. Sometimes it is impossible to say why one tree is affected by tent caterpillars and one is not. If you cannot reach the tent, see if you can disrupt the nest with a stick or broom handle, which will make it easier for birds to get to the caterpillars. If a tree has tent caterpillars and is otherwise healthy, there is no real reason to be concerned. Having tent caterpillars simply reduces the number of leaves. The time to be concerned is when it is a small tree and the entire tree is covered. Water your tree deeply since this will reduce stress on the tree.