Eastern Tent Caterpillar
from here: http://www.ag.auburn.edu/enpl/bulletins/easterntentcaterpillar/easterntentcaterpillar.htm
It is a foliage feeder and, as the name implies, a web- or tent-maker. Cherry, apple, and other trees of the rose family (Rosaceae) are the preferred hosts, but larvae have been reported to feed on a variety of hardwoods, including ash, birch, blackgum, oak, sweetgum, maple, and poplar.
The eastern tent caterpillar is common and often abundant in Alabama. It is among the first insects to break winter dormancy and become active in the spring.