They look like the bag worm critters that usually are found in wild cherry trees. I haven't noticed them yet here in central NC. Perhaps I just haven't looked up much. Lots of folks get rid of those trees. You can also take a long stick and wrap up a web loaded with the critters and stomp it, poison it or burn it.

Spray them off with a hose. Another name for caterpillars is "bird food". Think of all the hungry baby birds that these will feed.

It's been a heavy year for them. The earliest instars went after the boxwoods and Japanese hollies previous year's growth but the new growth has covered all the early damage.
From the photo, looks like these loopers are about full size and soon will drop to the ground to eventually become the wingless female or the male and the cycle begins again.

Most of your plants will recover if they have well set roots.

A flock of chickens would solve this problem in one weekend.

Mebbe hers but mine are 70-100 feet up raining down their poop.

How wonderful, dottie, for the birds migrating through your area as well as for the birds raising chicks in the nest.

The plants know very well how to survive this and the poop on the ground is just like slow release fertilizer.

esh, yup..pre-processed organic leaves..good for the earth but I'll still wear a hat.