HICKORY HORNED DEVIL
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.
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.
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.
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.
Web page last reviewed January, 2011 by the webperson.