Regal Moth: What It Is and When to See It

Citheronia regalis · Saturniidae

The Regal Moth (Citheronia regalis) is a large gray-and-orange giant silk moth with bold yellow spots, and its caterpillar is the famous Hickory Horned Devil - the biggest caterpillar in North America and, despite its menacing horns, completely harmless. Adults fly mainly in July and August and are recorded most in North Carolina, Virginia, West Virginia, Kentucky, and Tennessee. Like other silk moths the adult does not feed and lives only about a week, so look for it at lights on warm mid-summer nights.

Peak months
July, August
Most recorded in
North Carolina, Virginia, West Virginia

How to identify a Regal Moth

The adult Regal Moth is a heavyweight, with a wingspan of roughly 4 to 6 inches. The forewings are gray to slate, veined and edged in burnt orange, and dotted with cream-yellow spots; the hindwings flush orange with yellow markings. The body is thick and orange-banded. It has no tails and no eyespots, and its slow, heavy flight and large size make it stand out at a light sheet. Females are bulky and broad-winged; males are a touch smaller and slimmer.

Where it lives

The Regal Moth is a southeastern and mid-Atlantic species of hardwood forests. Open records place it most often in North Carolina, Virginia, West Virginia, Kentucky, and Tennessee, tied closely to the range of hickory, walnut, and related host trees. It is less common and more local than its cousins, so a single sighting is always a treat. Browse what else is flying in Virginia or North Carolina in summer.

When it flies

Adults peak in July and August, with a fairly short flight season. Because the moths emerge over just a few weeks and live only days, timing your light nights to mid- and late summer matters more for this species than for most.

The Hickory Horned Devil and life cycle

The caterpillar steals the show. The Hickory Horned Devil grows to about the length of a hot dog - North America's largest caterpillar - turning a vivid blue-green with black-tipped orange horns near the head. It looks terrifying but is entirely harmless: the horns are soft and it does not sting or bite. It feeds on hickory, pecan, walnut, sweetgum, persimmon, and other hardwoods. When full-grown in late summer it leaves the tree, burrows into the soil, and pupates underground without a cocoon, overwintering before the adult emerges the next summer.

How to see one at night

Adults come to UV and mercury-vapor light far more readily than to white LED, so a blacklight on a white sheet is the classic setup - moths respond most to short-wavelength light, and artificial light seems to disrupt the flight orientation they normally hold against the moon, leaving them circling nearby. Pick a warm, calm, moonless July or August night; check our good night for moths guide for the ideal conditions. New to mothing? Start with mothing for beginners, then run the predictor to see if Regal Moths are likely near you. For another spectacular silk moth, compare the Imperial Moth.

When Regal (Hickory Horned Devil) Moths are recorded (by month)

J
F
M
A
M
J
J
A
S
O
N
D

From 422 open-licensed GBIF records. Want what's flying at your spot tonight? Open the live tool →

Frequently asked

Is the Hickory Horned Devil dangerous?
No. Despite its size and spiky horns, the Hickory Horned Devil caterpillar is completely harmless - it does not sting or bite. The horns are soft and only for show.
How big does the Regal Moth get?
The adult has a wingspan of about 4 to 6 inches, and its caterpillar can reach the length of a hot dog, making it the largest caterpillar in North America.
When do Regal Moths fly?
Adults are on the wing mainly in July and August, with a short flight season, so mid-to-late summer nights are your best window.
Where can I find Regal Moths?
They are recorded most often in North Carolina, Virginia, West Virginia, Kentucky, and Tennessee, following the range of hickory and walnut host trees.
Do adult Regal Moths eat?
No. As a giant silk moth, the adult has no working mouthparts and does not feed. It lives only about a week, relying on fat stored from the caterpillar stage, just to mate.
What do Hickory Horned Devils eat?
They feed on hardwood leaves including hickory, pecan, walnut, sweetgum, and persimmon, then burrow into the soil to pupate.

More moths: Ailanthus Webworm Moth · White-lined Sphinx · Spongy Moth · Banded Tussock Moth · Polyphemus Moth · Virginian Tiger Moth · Salt Marsh Moth · Luna Moth · Hickory Tussock Moth · Forest Tent Caterpillar Moth

Per-species open-licensed GBIF records (CC0/CC-BY), aggregated from the precomputed index. Months and states reflect where the species is most recorded, not a complete range. Butterflies excluded. GBIF download DOI: 10.15468/dl.3w3w76.