I'm seeing a lot as well, though perhaps not as many as lalala. Do these do much damage to the trees? The leaves on my new (as of last summer) ornamental pear trees are looking pretty shredded, and I wonder if I need to spray them with something.

If it is winter moth that's in your area, they definitely love fruit trees. It's late, so they're probably almost done with damage, but you can still spray with a spinosad product like Monterrey Garden Spray. I tried it this year on my roses and ornamental cherry and it worked well. Early in the season you can use Bt. Both are organic and not too damaging to the environment. (Just don't spray spinosad while the tree is in flower because it is bad for bees when it's first sprayed.)