Identification of the forest tent caterpillar

A mature larva of the forest tent caterpillar

Forest tent caterpillar is a colorful caterpillar with many hairs. The sides of its body are blue with narrow orange stripes. Its back is black with conspicuous footprint-shaped white spots. Newly hatched larvae are very small, approximately one-eighth inch in length, and its body is black with conspicuous hairs. When fully-grown, the caterpillars are about 2 - 2.5 inches in length.

Newly hatched caterpillars, size comparison with a dime

Full grown caterpillars, size comparison with a dime