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HICKORY HORNED DEVIL

James R. Baker, Extension Entomologist Emeritus

CAUTION: This information was developed for North Carolina and may not apply to other areas.

Also called the regal moth, Citheronia regalis (Fabricius), Saturniidae, LEPIDOPTERA

General Information

Regal moths are large and have stout bodies. Females (wingspan of about 6 inches) are larger than males. The head and body are orange-red and yellow spots and markings. The wing veins are also red-orange. The dark areas between the veins are dull gray. The forewings of males are pointed toward the tips and narrower than the back wings. Each forewing has two large, light spots at the base and seven oval spots toward the outer edge. The back wings are rounded, with some yellowish shading at the base. The eggs are cream and smooth, shiny and oval (about 1/8 inch long).

The fully-grown hickory horned devil is up to 4.5 inches long with a brown head, dark green body, black prolegs and numerous spines. Each body segment has four or more short, black spines around in a row around it. The two body segments toward the front have four long projections each that are brown at the base, black at the tip and which curve back. These are the "horns" that give the caterpillar its ferocious appearance and name. The "horns" are sometimes 3/4 inch long. The shiny, dark-brown pupa is about two inches long or more and is somewhat cylindrical.

BIOLOGY

Hickory horned devils are found across North Carolina. Shade trees such as ash, butternut, button bush, cherry, hickory, lilac, persimmon, sassafras, sourwood, sumac, sweetgum, sycamore and walnut are commonly infested. Although each caterpillar may consume many leaves, damage is usually not severe because the worms are rarely abundant.

Regal moths emerge from the soil during the summer and mate. Female moths deposit eggs on leaves in small irregular clusters. The eggs hatch in about 16 days. The caterpillars develop through four larval stages, and grow to 4.5 inches long (our largest caterpillar!). In the last stages, the caterpillars have tremendous appetites. When disturbed, the caterpillars throw the front part of their body from side to side in a ferocious display. Despite their appearance, they are harmless. In late summer and early fall, the larvae burrow into the soil to pupate and overwinter. Most remain as pupae for 11 months although a few may take 23 months before developing into moths. Late caterpillars can survive moderate frosts and continue to feed as the temperatures warm up. There is only one generation per year throughout most of its range, but there may be a small second generation of hickory horned devils in the South.  Populations seem to be declining.

Control

The hickory horned devil has never been reported to be abundant enough to be considered a pest and appears to be less common than in years passed. Because they are harmless to people, no pesticide recommendation seems to be appropriate.

Fun Links

http://www.naturalsciences.org/funstuff/notebook/inverts/hickory_horned_devil.html


Other Resources

For assistance with a specific problem, contact your local North Carolina Cooperative Extension Service personnel.

Published by North Carolina Cooperative Extension Service

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

© 2001 NC Cooperative Extension Service

Prepared by: James R. Baker, Extension Entomologist
ENT/ort-108 September 2001

Web page last reviewed January, 2011 by the webperson.