Ooh you are lucky to have only one. I have several, and am still trying to get rid of them. If I remember correctly, they are the larvae of a moth or butterfly. I don't know which one or even if they are "good" ones.
Dad used to burn them out. Take a long stick or pole, wrap something burnable around it and set it afire. The long stick enabled you to reach way up in the tree. Just be VERY careful not to set anything else on fire. We did that earlier this year when I notice them starting to get closer to our house. But some of the burning web, fell onto a pile of very dry leaves. Luckily I had noticed more smoke than there should have been and we got it out quickly.
I don't mind them too much in the woods, but don't want them up around the house. I figure this way if they are good worms, I am not doing too much damage, and if they are bad worms, then maybe nature can take care of it herself. I keep hoping the birds will eat them.
Tammy

I'll stick with the Real-kill Wasp & Hornet Killer .
It sprays up to 20 feet , and does a very good job of eliminating the worms . Anything higher than 20 ft. ; I'll just let nature take it's course !!!
By the way , the local cuckoos love to feed on those worms .

From what I read the webworm comes from a white moth with dark spots on its wings. Apparently these webworms are not considered an important pest because by fall the trees have produced and stored enough energy resources for their survival and growth. So other than defoliating the tree, I guess the harm is not significant. Sure looks ugly and THEY sure are ugly. Also said early summer generation of these webworms is not as numerous.

I'll be out checking for more though.

Webworms are heavy in NE OK. We took a drive today and trees of all sizes are infested. Many hickory and black walnut in our neighborhood are covered with webs.

I believe if you put a ring of sticky tape around the tree or a stick product made to keep crawling worms etc out of trees you can prevent this from happening again