Large trees tolerate some feeding injury without harm. Trees repeatedly attacked, or having some other problem, may need spraying. Tent caterpillars form nests in trees then eat the foliage. The nests can be pruned out when small. Chemical controls for tent caterpillar are Orthene, Diazinon, malathion, or methoxychlor.
Twig pruner causes twigs to drop off in late summer.
The larvae ride the twig to the ground. Rake up and destroyed fallen twigs. Lace bugs suck juices from leaves causing them to look dusty or whitish gray. Use sprays of Orthene, rotenone, or malathion when lace bugs are first noticed then again in 10 days. Spraying may be repeated in several weeks.