Regal Moth (Hickory Horned Devil)
Citheronia regalis (F.) (Saturniidae)
L.L. Hyche, Associate Professor
Department of Entomology & Plant Pathology
The regal moth is an eastern species, occurring from New England to Florida west to Texas and Kansas. The caterpillar (Photo 1) feed on foliage of butternut, walnut, hickory, pecan, sweetgum, persimmon, and sycamore.
Life Cycle, Description, and Habits
The species overwinters as a pupa in the ground. Adults emerge in June. The regal moth (sometimes called the royal walnut moth) is a large moth with wingspan of 100-125 mm. The body is orange. The front wings are grayish with red-orange veins and yellow spots; hind wings are mostly orange with some yellow markings.
The larva, commonly called the hickory horned devil, is one of the largest found in the area. The full-grown caterpillar (Photo 1) is 100-125 mm long. The head is orange and the body bluish green or sometimes brownish. Useful distinguishing structures are the long conspicuous spines or horns on the thorax; there are two on the first thoracic segment and four on each of the second and third segments. Thoracic horns are usually orange tipped with black, but sometimes may be mostly black. Rows of short black spines occur along the back and sides of the body.
Caterpillars are generally present from July through September. When fully grown, larvae enter the soil and pupate. There is one generation each year throughout most of the range, but a partial second may occur in the southernmost area.
Occurrence, Damage, Importance
The hickory horned devil is a solitary feeder, and is seldom present in sufficient numbers to cause serious loss of foliage. It is most often encountered in Alabama in August and September. The full-grown, “horned” caterpillar is a fearsome-looking creature, but actually is quite harmless. It has no “stinging” or nettling spines.