Wash your contaminated clothes as well, as a few hairs or spines might remain. Degree of severity of the rash depends on the caterpillar species and the individual human’s physiology, and it is rarely a cause for concern. It lives in Canada and the eastern U.S. and favors a diet of oak, maple, walnut and ash leaves. Most of these caterpillars come in a range of colors from bright yellow to bright white even within the same species. These are called “pencils” and are found with one on each “corner” of the body, sort of like a black spot at each corner of a rectangle. Discover Life's page about the biology, natural history, ecology, identification and distribution of Caterpillars -- identification guide -- Discover Life. The adult female moth lays her eggs in May or June on a variety of trees, such as walnut, ash, elm and oak, besides the hickory from which they get their name. Again, each of these caterpillars is native to Michigan, and the irritation caused by contact with hairs is a natural defense mechanism against predators. Black Caterpillar Identification and Guide If you found a black or dark-colored caterpillar, this quick and easy guide can help you identify it. There are also four small areas on the body where there is a very thin cluster of black hairs that are longer than the rest of the fuzz. Sometimes, the black line looks more like individual tufts than a line. She worked as a researcher and analyst in the biotech industry and a science editor for an educational publishing company prior to her career as a freelance writer and editor. Like the yellow-spotted tussock caterpillar, the white woolly worm sports clusters of longer bristles that stick out, in either black or white. American dagger moth caterpillars are bright yellow … They are sometimes called white woolly bears or white woolly worms, even though younger caterpillars are often yellow. They don’t sting or have venom, but the bristles can cause a stinging sensation if they penetrate the skin. In about two weeks, an orange-yellow moth with 1 ½ to 2-inch wingspan emerges. Woolly caterpillars, also called woolly worms, are named for the stiff, hair-like bristles that cover their body. This may prevent birds from spotting the white woolly bears due to their feeding activity. The caterpillars of the American dagger moth are white with a few longer black “hairs” sticking out. To properly identify these caterpillars requires a prepared specimen with a microscope. he says. Woolly bear caterpillar food includes flowers, grasses and the leaves of flowering plants such as clover. This caterpillar identification page will help you identify some of the most commonly seen caterpillars. Any late season feeding is on plants that are already preparing to shut down for winter. "If it is in a place where it can cause problems, clip off the leaf or use a stick to relocate it," Ric Bessin, an entomologist at the University of Kentucky College of Agriculture, tells USA TODAY. The fuzzy caterpillar of the Isabella tiger moth is best known as a woolly bear.