Bug card No. 1155 of 1,500

Regal moth

Citheronia regalis

Eats: Nothing as a grown-up MothsForests and woods6 legs

The regal moth is a giant, royal-looking moth from North America. Its caterpillar is even more famous: a huge green caterpillar with big red horns tipped in black, called the hickory horned devil. It looks scary, but it is really a gentle giant.

Lives in

Eastern and southern United States, in leafy forests

Wingspan

9.5 to 16 cm (3.7 to 6.1 in)

Top speed

about 28 km/h (17 mph)

Flying, estimate

Can it hurt you?

Harmless

Harmless. The caterpillar's horns are prickly but they do not sting, and it is one of the easiest big caterpillars to hold.

What does it eat?

The grown-up moth has a tiny mouth and does not eat. The caterpillar eats leaves of walnut and hickory trees, and a big one can strip whole branches bare.

Photo of Regal moth — Picture by (c) John P Friel, some rights reserved (CC BY). CC BY 4.0, via Wikimedia Commons.

How big is it?

How wide are its wings?

wings as wide as your handcould fly across a whole football pitch in 14 seconds

How big is Regal moth compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

How fast is it?

A kid running fast about 13 km/h (8.1 mph)

A grown-up on a bike about 25 km/h (16 mph)

Regal moth about 28 km/h (17 mph)

A car driving in town about 50 km/h (31 mph)

cool stuff

Fun facts

It is the heaviest moth in North America north of Mexico.

The caterpillar can grow up to 15 centimetres long, as long as a pencil.

Young caterpillars curl up during the day and look just like bird droppings, so birds leave them alone.

Just before it changes into a moth, the caterpillar turns from green to turquoise blue.

It does not spin a cocoon. It digs a little room in the soil and changes there.

you asked

Most asked questions about Regal moth

?Is the hickory horned devil dangerous?

No. It looks fierce, but its spines do not sting and it is harmless.

?How big is a regal moth?

Its wings are about 9.5 to 15.5 centimetres across.

?How long does a regal moth live?

The grown-up moth lives only about a week, because it cannot eat.

Myth buster

Myth: The hickory horned devil is dangerous and can sting.

Truth: No. It looks scary, but its spines do not sting and it is completely harmless.

For bug experts

Scientific name: Citheronia regalis
Named by: Fabricius, 1793
Group: Moths
Family: Saturniidae
Classification: Insecta > Lepidoptera > Saturniidae
Lives on: North America
Also known as: Royal walnut moth, Hickory horned devil

Where the facts come from

Citheronia regalis (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
Picture by (c) John P Friel, some rights reserved (CC BY). CC BY 4.0, Wikimedia Commons. The round sticker of this bug is cut from the same picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at hello@bugwiki.app and we will fix it.