Tent caterpillars in the wild black cherry trees along the interstate have begun building their homes in the limbs. Like most caterpillars, each of the crawlers is basically a “stomach with legs”. Their existence is dominated by the urge to eat as many leaves as possible in the shortest time period.
Cherry limbs (and trees!) can be completely defoliated in a few days – but the damage is not permanent. The caterpillars will soon drop from the tree and change into pupae in the ground. In a month or so, small butterflies will hatch under the tree. At the end of the summer, they will lay a mass of eggs on small twigs in nearby cherry trees.
No control measures are really necessary unless the webs mar the landscape or the caterpillars are dropping onto a deck. Destroying the “tent” exposes the critters to birds and other predators. An organic pesticide containing Bacillus thuringiensis (Thuricide, Dipel, and Caterpillar Attack) will kill many worms and stop their feeding.