S.K.
We had web worms in our pecan tree. Arborists are expensive and I am a DIY gal so I used an insecticide and a hand held sprayer that I bought at Home depot. I put it on "stream" and sprayed them myself. They started falling on the ground which was pretty gross. I didn't cut the limbs. The tree is fine now. You can get bottles of insecticide that hook up to the hose and will spray pretty far up into the tree.
Good luck.