Hickory Horned Devil (larva), Regal Moth or Royal Walnut Moth,Citheronia regalis (Fabricius) (Insecta: Lepidoptera: Saturniidae: Citheroniinae)
The imposing larva, known as the hickory horned devil, is most often observed when it is full grown and comes down from the trees to wander in search of a site for pupation.
The hickory horned devil is among the largest of our native saturniid caterpillars. It is 12.5 to 14 cm in length – about the size of a large hot dog. The caterpillars vary slightly in color, but are commonly blue-green. The second and third thoracic segments each bear two long and two shorter orange, black-tipped scoli (tubercles in the form of spinose projections of the body wall). The abdominal segments each have four short, black scoli, and segments 2 through 8 have a pale, oblique lateral stripe. Although the larva has a fierce appearance, it is harmless.
The regal moth is a beautiful and fascinating member of our native fauna, and its larvae should not be killed. If a larva is found crawling on pavement or in an area of thick turf grass where it would have difficulty burrowing, it should be moved to an area of soft soil or a mulched area where it can burrow for pupation.