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?
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.