What kind of moth is this?

A large moth – about three inches long – was resting on the library’s back door, and we wanted to try and identify it. Its fuzzy-looking legs and body were a rusty orange color and its grey wings were veined with the same shade of orange. Both its body and wings were patterned with ivory markings.  

One of our librarians checked the Moths of Ohio Field Guide on the Ohio Department of Natural Resources website while another looked in Butterflies and Moths: A Guide to the More Common American Species by Robert T. Mitchell and Herbert S. Zim. At the same time, we both came across the Regal Moth, also known as the Royal Walnut Moth. Its distinctive colors and markings matched our moth’s exactly.

The Regal Moth is active in Ohio during June and July. While it’s more common in the southern part of the state, it can be found wherever its food sources (hickory and walnut, primarily) are available. The adult moth actually doesn’t eat or drink at all. It only lives about a week, long enough to mate and lay eggs. The larva can grow to be about six inches long, “the size of a small hotdog,” according to the Moths of Ohio Field Guide. It’s called the Hickory Horned Devil after its favorite food and inch-long red spikes. As ferocious as it looks, though, the Hickory Horned Devil is harmless; its spikes are just for show.