What Plants Do Woolly Caterpillars Eat?

Wild Herbaceous Plants

• Woolly bear caterpillars dine on the leaves of herbaceous plants such as sunflowers, lambsquarters, spinach and grasses. Herbaceous plants are flowering species that wilt to the ground during autumn and winter. Although their stems, flowers and leaves die, herbaceous plants' roots survive underground when temperatures are low. When the temperatures warm in spring, perennial herbaceous plants renew their growth cycle. Some herbaceous plants are annual or biennial, meaning they live for only one or two years.

Deciduous Trees

• Deciduous trees drop their leaves during autumn and winter, conserving energy until spring. Before the trees lose their leaves, though, woolly caterpillars eat their vegetation. Oak, beech, sourwood, willow and chestnut are some deciduous trees that host woolly caterpillars. Woolly caterpillar species found on deciduous trees include the gypsy moth caterpillar and the pale yellow green caterpillar.

Landscape Plants

• Landscape plants are rarely a target for woolly bear caterpillars because the caterpillars usually eat leaves from wild herbaceous plants, but the woolly bear caterpillars attack landscape plants if the pickings are slim for wild plants or weeds. When they eat landscape plants, woolly bear caterpillars usually stick with herbaceous varieties such as barberries and asters. Woolly bear caterpillars are difficult to remove from landscape plants due to their girth. Handpicking is a recommended method for gardeners to rid their gardens of the caterpillars.

Evergreens

• The fall webworm and Western tent caterpillars eat leaves on evergreen trees, especially conifers. Evergreens do not drop their leaves in autumn or winter. The fall webworm is a white-colored caterpillar, while the Western tent caterpillar features orange and black hairs. Fall webworms do not subject evergreens to a significant amount of damage, but the Western tent caterpillars usually cause needle loss and damage evergreen sapling growth.

Alkaloids

• Plants are a source of alkaloids, which is sometimes a lifesaver for woolly bear caterpillars. Parasitic flies lay their eggs within woolly bear caterpillars during spring with the intent of the hatched larvae preying on the caterpillars. Alkaloids, however, offers medicinal properties for the caterpillars, either eliminating the larva parasites or boosting the woolly bear caterpillars' immune system.