Eastern tent caterpillars (Malacosoma americanum) build unsightly silk tents in cherry, apple, and other landscape trees in early spring. The caterpillars feed on leaves of these host trees, and may cause significant defoliation when present in large numbers. Caterpillars wander when they are ready to pupate, crawling on houses and decks.
First, be sure you have eastern tent caterpillars, and not another similar pest. Eastern tent caterpillars build their tents in the crotches of tree branches and appear in early spring. Fall webworms also build tents, but their tents will be at the ends of branches, enclosing foliage. Fall webworms also appear at an entirely different time of year - fall, as you can probably guess. Some people confuse eastern tent caterpillars with gypsy moths. Gypsy moths do not construct tents, and usually appear a little later in spring than tent caterpillars.
Eastern tent caterpillars rarely infest ornamental trees in large enough numbers to kill your landscape plants. Because they appear in early spring and complete their life cycle by summer, the host trees have time to produce more leaves after being defoliated. If you have a few caterpillar tents in an apple or cherry tree, don't panic. Control of the pests may not be necessary at all. If the infestation is significant or you just can't stand the sight of caterpillar tents in your trees, there are some things you can do: