The regal moth is the adult form of the caterpillar known as the hickory horned devil.
Its scientific name is Citheronia regalis, and it belongs to the giant silk moth family, Saturniidae. The caterpillar is famous for its large size, green body, and prominent orange-and-black spines. Despite its intimidating appearance, the hickory horned devil is harmless to people because its spines do not deliver venom.
The adult regal moth looks very different from its larva. It has broad, rusty-orange wings marked with yellow spots and dark veins, while the adult has greatly reduced mouthparts and does not feed. Its primary purpose is reproduction after emerging from the pupa.
The species is native to the eastern United States. Caterpillars feed on trees and shrubs including hickory, walnut, sweetgum, persimmon, and ash. A common mix-up is confusing the regal moth with other large North American saturniids, such as the cecropia and polyphemus moths; their caterpillars and adult wing patterns are different.