The banded woolly bear larva emerges from the egg in the fall and overwinters in its caterpillar form. It survives winter freezes by producing a cryoprotectant in its tissues. Once the weather warms, the larva devours all the grass and weeds it can, pupates, and becomes an adult, which then lives through the summer. It is the larvae of this species which are the subject of common folklore, which has it that the forthcoming severity of a winter can be predicted by the amount of black on the caterpillar. Recent research has shown that the woolly bear caterpillar may eat alkaloid-laden leaves to help fight off parasitic fly larva that can be laid inside their abdomens. This research showed what is called 'the first clear demonstration of self-medication among insects'.
The larva is black at both ends, with or without a band of coppery red in the middle. The adult moth is dull yellow to orange with a robust, furry thorax and small head. Its wings have sparse black spotting and the proximal segments on its first pair of legs are bright reddish-orange.
This species is a generalist feeder - it feeds on many different species of plants.