Caterpillar Web in Canadian Choke Cherry
On 8-25-20, I noticed a caterpillar web about 25 feet up in our Canadian Choke Cherry tree in Sisters, OR. I've attached two photos. With binoculars, I can see the caterpillars moving in the web. Can you tell me your best thoughts on what it might be, whether it will be detrimental to the trees health, and if I should spray to kill the caterpillars or just let them be. Thanks
Deschutes County Oregon
Tent caterpillars aren't usually a significant threat to healthy, mature trees. They do strip away some of the trees' leaves and weave unpleasant looking webs, but that's the worst of their damage. But, there are two exceptions: black cherry trees and young trees are extremely vulnerable to tent caterpillars. The safest and most effective method of dealing with webworms is as follows: Prune the tree in the spring and spray with a lime-sulfur and dormant oil spray.