The Regal Moth, or Royal Walnut Moth, Citheronia regalis certainly lives up to its name. This large, distinctively patterned moth is said to be the largest moth by weight, north of Mexico. Its normal habitat is east of the Mississippi River, becoming more common in the Deep South. The rusty orange, gray and cream colored markings are unique and it could never be confused with any other insect.

ImageThese beautiful moths are members of the Saturniidae Family and can count other beauties, such as the Luna Moth, Actias luna and Imperial Moth, Eacles imperialis, among its cousins. These are generally large, attractive moths sporting distinctive colors, shapes or patterned eyespots. Like other members of the family, Regal Moths emerge from their pupa stage without functioning mouth parts and their sole purpose is to find a mate and procreate. They live about 10 days, subsisting on stored nutrients left over from their caterpillar stage.

And what a caterpillar stage it is! Imagine coming face to face with a bright green caterpillar covered with black spines and sporting red 'horns' on its head. If this isn't weird enough, the mature caterpillar is about the size of a hot dog! ImageMost caterpillars are simply known as the larval stage of whatever adult they may morph into, but this fellow even has its own name; the Hickory Horned Devil. As fierce and dangerous as this may sound, the caterpillars are docile and harmless. The term 'paper dragon' comes to my mind when I think of them, as they resemble the cloth and paper costumes used in the Chinese Dragon Dance.

The female Regal Moth lays her eggs on many familiar hardwood nut and fruit trees and the caterpillars hatch after about 10 days. The little guys don't resemble the mature caterpillar much except for their spines and horns. They start out black, then turn brown, tan, light green and finally bright turquoise green just before they burrow into the ground to pupate. These are solitary caterpillars and even though they reach a hefty size, are rarely a pest on the trees they dine on. Host plants include hickories, sumacs, persimmons, walnuts, ash and sweetgums. It takes between 35 and 45 days for the caterpillar to go from hatchling to mature and ready to pupate. When the mature moths emerge, the female immediately starts emitting pheromones which males can smell for several miles. They are nocturnal moths, but often will be attracted to streetlights.

ImageDeclining habitat and pesticides have diminished their numbers and often the average gardener has never seen a Regal Moth. You can help by planting their favorite host plants, especially members of the Carya family. Limit, or eliminate pesticides. The caterpillars need loose mulch and leaf litter for burrowing, so leave a bit of those materials available for them. Sometimes a bit of untidiness in your garden makes all the difference in the survival of some of our most beautiful and unique creatures!

The Hickory Horned Devil image is courtesy of Tom Woodward and Wikimedia Commons