Woolly Bear Caterpillar

The woolly bear caterpillar is the larval stage of the Isabella tiger moth, most commonly referring to the banded woolly bear, *Pyrrharctia isabella*.

The woolly bear caterpillar is the larval stage of the Isabella tiger moth, most commonly referring to the banded woolly bear, *Pyrrharctia isabella*. It is a fuzzy, black-and-rust-coloured caterpillar found across much of North America, including southern Canada, and is known in folklore for supposed winter-predicting abilities.

Identification

The banded woolly bear is easily recognized by its fuzzy appearance and contrasting colour bands. Its bristles are black on the ends and reddish-brown in the middle, though colour can vary with age and feeding conditions.

Life cycle

The caterpillar hatches, feeds through warm months, and survives winter in the larval stage. In spring it spins a cocoon and later emerges as the Isabella tiger moth.

Habitat and range

Woolly bear caterpillars occur across much of North America and are commonly found in meadows, gardens, fields, and other places with vegetation. Sources note their presence in the United States, southern Canada, and parts of Mexico.

Diet

Woolly bears are generalist plant feeders. They consume many herbaceous plants and may also feed on common garden crops and ornamentals. Their diet includes violets, clover, dandelions, nettles, sunflowers, spinach, cabbage, and other herbaceous vegetation.

Folklore

In North American folklore, the size of the caterpillar's brown band is sometimes said to predict winter severity. Scientific sources describe this as a popular belief rather than a reliable forecast.