Are you referring to bagworms or tent caterpillars/webworms? I know that I probably removed 50 or so bagworm cases last Fall (we have alot of evergreens). I haven't seen any tent caterpillars yet this year, but typically we do get a few.

You can spray tent caterpillars/webworms with BT when they are young. I typically just break up the nest a little so that the birds can have at them. Sometimes it works, sometimes it doesn't.

Ugh!!! I have a nasty wild cherry tree that literally was/is draped in webbing... including the truck and down to the ground! It actually creeped me out when I noticed how completely they had covered the tree.

If you notice it when they're really small you can just take a stick and do like you'd do with a spider's web- twirl the stick in the webbing and it'll gather they whole mess up, caterpillars and all. When they get bigger it's a lot harder to do that. They especially like cherry and apple tree family members, so watch there first. I check my trees in the winter for the egg sacs, which look like a rounded bump on the stem and scrape it off.

Ok, thanks for the help guys. I think they are caterpillars.
For now I'm just trying to destroy them the best way I can ( and what I can reach) with a stick and stomping on the ones that hit the ground , hopefully the wild birds will help from there out.

Magick, that sounds creepy crawly , literally.

It really was... Also kinda cool in a dark artsy kind of way.

They love the wild cherry trees around here too and give me the shivers!