University of Kentucky Department of Entomology

Mystery Bug Answers

Mystery Picture #2

Mystery Picture #2

(Mystery Picture #2)

Hickory Horned Devil

This is the caterpillar of the Royal Walnut Moth (Citheronia regalis) and is also known as the Hickory Horned Devil. These two common names identify the caterpillars' favorite host plants, however caterpillars will also feed on sumac, sweet gum, lilac, persimmon, ash and beech. They are the largest of the silk moth caterpillars and commonly grow to five inches. The long barbed horns on the forward end of the body make the caterpillar look intimidating but it is entirely harmless to humans. The full grown larva may be still active in late September and October in Kentucky, and reportedly light frosts do not deter its feeding activities. Unlike typical saturniids, this caterpillar burrows into the ground to pupate. The moth emerges in late June to early July and has a wingspread of six inches. The front wings are gray-brown spotted with yellow and brown wing veins.

To read about other relatives of this moth, see ENTFACT 008 - Saturniid Moths.

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