DISTRIBUTION:

Citheronia regalis, The Hickory Horned Devil, (wingspan: males: 96-125mm; females: 109-147mm) ranges from southern Vermont and New Hampshire south to Florida and westward to eastern portions of the Great Plains.

Although this species is still (2010) quite common in some areas, particularly in the southeastern states, from Maryland southward, it is rare or possibly even extirpated from the New England states and northward.

FLIGHT TIMES AND PREFERRED FOOD PLANTS:

Regalis fly from late June to mid-August. They have been taken in early June in Maryland and probably fly in May in more southerly states where there would be at least two generations each year.

Larvae prefer various nut trees: hickories, walnuts, pecans, and butternut, but other species of sumacs, ash, sycamore, etc., are readily accepted.

Because of its rapid growth, relatively small size, and ease of transplanting, Staghorn sumac (Rhus typhina) is often used as a hostplant by rearers.

Willow and sweetgum are usually also also good foodplant choices.

Citheronia regalis male, courtesy of Viktor Suter and Bernhard Wenczel.

ECLOSION, SCENTING AND MATING:

Adult Citheronia regalis emerge from 9:00-11:00 P.M. and remain quiet until the following evening.

Females generally call from 11:00 pm until 2:00 am. with males on the wing shortly after dusk. Pairs remain coupled until the following evening. Upon separation, the females begin ovipositing shortly after dark. Males are readily attracted to light; females much less so.

EGGS, LARVAE AND PUPAE:

Yellowish eggs (2mm) are deposited either singly or in groups of up to four on upper and under surfaces of hostplant foliage. Incubation lasts 7-10 days with larvae becoming visible through transparent eggshells a day or so before emergence. Only put a couple of eggs in each incubation chamber/container as regalis eggs seem to give off a gas which may be toxic to other eggs or may condense on other eggs causing suffocation.

Warmth hastens incubation and larvae are relatively large upon emergence. Female regalis will readily oviposit on the insides of brown paper grocery bags.

Larvae (full grown at 15 cm long) are solitary nighttime feeders in early stages when they curl up in a "j" shaped pattern during the day and resemble two-toned bird droppings on upper leaf surfaces. Larvae, in all instars, thrash their heads about violently when disturbed, using their well-developed armaments to frighten would-be predators.

My experience has been that the early instar larvae are not very clingy, and they sometimes fall to the bottom of the sleeve if disturbed.

In later instars Citheronia regalis larvae also feed during the day and grow very rapidly with very efficient assimilation of host plants, especially Rhus. All regalis images (copyright) on this page, unless noted otherwise, are courtesy of John H. Campbell. To the right, a third instar larva has not yet taken on the green coloration of the final two instars. Larvae are quite disease resistant and do very well in outdoor sleeves.

It is easy to see how the moth came to be known as the Hickory Horned Devil from the menacing display of non-urticating, generally harmless, body spines. This fifth instar larva can reach a length of six inches in just a little over four weeks. Larvae to the right, on sweetgum, will descend tree in a few days searching for soft earth in which to pupate. Visit Citheronia regalis adults, eggs, larvae, and photo setup, courtesy of Leroy Simon. Visit Citheronia regalis first, fourth and fifth instar, courtesy of Ryan St. Laurent. Visit Citheronia regalis eggs, various instars, pupa, male and female, courtesy of Jean-Yves Malmasson. Visit Citheronia regalis prepupal, focus stacking, courtesy of Rod Millar.

I still remember a time when my father and I were visiting some friends. As we got out of the car, parked under a large walnut at the end of the lane, a dropping approximately 3/8 inch wide and over 1/2 inch long hit the engine bonnet and rolled to the ground, joining several other such offerings. My father looked up and spotted two gigantic devils feeding on outer leaves. Larvae can be found in the wild when inspecting trees for stripped foliage.

Pupation is normally deep underground, but most of the earth pupators can be induced into pupating in any dark enclosure.

My father has had regalis pupate regularly in the dark chambers of a closed fishing tackle box. I regularly have Sphingidae pupate under paper towelling in large buckets placed in a warm dark closet. The smooth, stout pupa has a relatively short cremaster.

Regalis pupae should be stored just above freezing; sprinkling in June with air temperature water sometimes helps induce eclosions. Moths tend to eclose in a synchronized fashion and it is not difficult to obtain pairings even in a relatively small cage.

Photo courtesy of Mark Deering.

Occasionally regalis larvae will approach seven inches in length.

Recommended reading for those who wish to rear this species:

Citheronia regalis: Do's and Don'ts
Rhus typhina: Staghorn Sumac
Earth Pupators
Citheronia hybrids
Whopper Citheronia regalis!
Citheronia regalis, Egg Care, Dry Envrionment
Another Rescue
An Emergence Cage for Citheronia Regalis

I usually have eggs for sale in June, and pupae for sale in October-November. The pupae are usually sold out before Christmas.

Many of you received Citheronia regalis eggs from Ty Clark in Maryland 2013 and 2014. Ty writes, "Well the results of my experiment with Pecan are about in. I was only able to rear four larvae on my small tree due to its size, but they all came in as the largest regalis I’ve ever reared, and substantially larger than any of the 500 or so that I’ve reared on sweetgum, sycamore, sumac, hickory, or walnut. They about stripped the entire tree so I’m going to baby it next year."

Citheronia regalis fifth instar on pecan, Maryland,
courtesy of Ty Clark.

Larval Food Plants

Listed below are primary food plant(s) and alternate food plants listed in Stephen E. Stone's Foodplants of World Saturniidae. It is hoped that this alphabetical listing followed by the common name of the foodplant will prove useful. The list is not exhaustive. Experimenting with closely related foodplants is worthwhile.

Carya glabra Carya illinoensis..... Carya ovata Cephalanthus occidentalis..... Corylus Diervilla Diospyros virginiana Fraxinus Gossypium herbaceum Juglans cinerea Juglans nigra Juglans regia Ligustrum Liquidambar styraciflua..... Nyssa sylvatica Oxydendrum arboreum Platanus occidentalis Platanus occidentalis Prunus domestica Prunus serotina Quercus Rhus cismontana Rhus choriophylla Rhus glabra Rhus laurina Rhus typhina Salix Sassafras albidum Syringa vulgaris

Pignut hickory Pecan Shagbark hickory Button Bush Hazel Bush honeysuckle Common persimmon Ash Levant cotton Butternut Black walnut English walnut Privet Sweetgum Black gum Sourwood American plane tree/Sycamore Oriental sycamore Garden plum Wild black cherry Oak Mountain sumac Sumac Smooth sumac Laurel sumac Staghorn sumac Willow Sassafras Common lilac

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The pronunciation of scientific names is troublesome for many. The "suggestion" at the top of the page is merely a suggestion. It is based on commonly accepted English pronunciation of Greek names and/or some fairly well accepted "rules" for latinized scientific names.

The suggested pronunciations, on this page and on other pages, are primarily put forward to assist those who hear with internal ears as they read.

There are many collectors from different countries whose intonations and accents would be different.

The species name "regalis" comes from Latin and Greek meaning royal, probably alluding to the majesty and coloration of this species.

The source of the genus name "Citheronia" is probably Mount Citheron (Greek mythology), an untamed wilderness, exempt from the laws of civilization. The goddesses go naked there and are free from any of the pressures of society.