Chris,
I've got the same problem over in Acushnet. I was too late this season to stop them before they hatched. But I've had good success killing off the little MF's and keeping them off the house and ornamental trees. I was trying to avoid using pesticide, but it became necessary.
So far I've been using Befenthrin (Ortho MAX). You could use Carbaryl (Sevin) but it's a bit nasty. Mix up a couple of gallons in the pump sprayer and go hunting.
You'll need to think like one of those little caterpillars to kill 'em good. They go up in the trees at night and come down to hide during the daylight. They like to hide under leaves, bark pieces, shingles, the edge of the sill of your house where the concrete meets wood, under trash can lids, etc. Spray their hiding places during the day. Also, spray any ornamental trees that show signs of caterpillars. Under the eaves of the house and edges of the house roof I also sprayed. They haven't been back in days. Go prowling around the yard in the afternoon when the sun is starting to go down a bit and look for the big masses of caterpillars hanging on the sides of buildings and roof edges to maximize the kill.
You can also do things to trap them and stop them from climbing back up the trees. Wrap the tree truck about a foot wide with duct tape and smear the tape with vasoline or something else really sticky. They'll get stuck and die. You can also wrap the tree truck with burlap and go kill 'em when they go under the burlap to hide for the daytime. Another thing I've done is to make a circle of leaves around the base of the tree and spray it real well... . this kills 'em nicely when they try to go back up the tree at night.
For next season, start by collecting all of the egg sacs you can find and destroy them by burning or soaking well in soapy water for a while (I'd personally opt for the burning as it's more satisfying :-laf ) Do this by March or they'll already have hatched. Each sac can produce 1000 caterpillars

Keep a close eye on the trees for the first signs of the little baby caterpillars and webs. As soon as you see 'em then spray the whole dang area with Bacillus thuringiensis. That'll take out the baby caterpillars before they get a foothold, but it does not work on the bigger ones.
Sean