Woolly Bear Caterpillar
Arizona Community Integrated Pest Management
Woolly bear caterpillars, also known as woolly worms or woolly bears, are actually the larvae of the Isabella tiger moth (Pyrrharctia isabella). In the fall, these caterpillars start their annual crawls in search of sheltered quarters for winter. This is usually the time that you may see noticeable numbers of these caterpillars crossing roads.
These caterpillars have alarm-orange bands on their back and short stiff hairs throughout the body. Some think that these sharp-pointed bristles may harm people or pets. In fact, these bristles/hairs serve as a defense against many types of predators and protect the caterpillars. They are not stinging hairs and don’t inject venom. However, hypersensitive individuals may suffer severe reactions if the hairs penetrate their skin.
These caterpillars may display high variability in their coloration, possibly linked to caterpillar age, food sources, and moisture levels in the region where they develop.
According to legend, the length of the black on the woolly bear caterpillar in the fall can predict the severity of the coming winter. The longer the black bands, the longer, snowier, and more severe the winter will be. It would be purely entertaining to find this legendary caterpillar and make a prediction about the winter to come!