I had the misfortune a few years ago to find that bagworms do indeed cause problems in NE. I had a lovely Arborvitae that was about 7' tall and it was totally destroyed by them. I tried to handpick them, but just couldn't keep up with them. I would bring gloves home from work and pick over 1000 every day for days and days. Yes, I did count how many I picked. Gave me something to do while picking them off the tree. They even cause damage to my barberry bushes. Thankfully enough, they don't seem to have come back since then or at least not in numbers enough to be a problem. Thanks for sounding the warning about them.
