Publication 444-225, August 1996
Species: There are several species of moths which may be considered "curiosities" of nature because of their large size and bizarre appearance. People usually encounter them by chance. These moths almost never cause significant damage. Pictures and characters which should help you identify them are given below.
Cecropia Moth. This is our largest moth; in some individuals the wings measure over 6 inches tip to tip. Both front and hindwings are brown with white and red wavy lines and crescent moon shaped markings. There is one generation per year. The caterpillars are pale green with distinctive yellow spots along the sides of the body. They feed on cherry, plum, elderberry, apple, boxelder, maple, walnut, birch and willow. Cecropia moths overwinter in large, tough cocoons attached lengthwise to twigs.
Polyphemus Moth. Our most common giant moth measures 3.5 to 5.5 inches, wing tip to wing tip. This insect was named after a one-eyed giant of Greek mythology. Two black and yellow eyespots are set against a buff-colored background on the hindwings.
Normally, when this moth is at rest the eyespots are hidden beneath the forewings. When disturbed, the forewings are pulled forward and the sudden appearance of two large "eyes" is often enough to scare away potential predators, usually birds. The caterpillars are bright green with red spots along the sides of the body and a vertical yellow stripe on each segment. They feed on oak, hickory, elm, maple, birch, and a variety of other trees and shrubs. Cocoons are rounded and parchment-like, and usually found hanging from the food plant.
Great Leopard Moth. This moth is named for its black and white wing pattern which resembles the spots of a leopard. The abdomen of the moth is dark blue with orange markings. The caterpillar is covered with stiff black hairs and has crimson rings between segments; it feeds mainly on plantain.
Io Moth. The Io moth, named for a character in Greek mythology, has a conspicuous black eyespot on each hindwing. Males are golden yellow in color, whereas females are more brown. The caterpillar is yellow-green with a red and a white stripe extending laterally along the body. This caterpillar is covered with numerous irritating spines. Io larvae stay together, often moving in long trains.
Luna Moth. Surely this is one of our most beautiful insects. Adults have light green wings up to 4.5 inches across. Two long, trailing "tails" extend back from the hindwings. The caterpillars are yellow-green with tiny red spots along the sides and top of the body. They feed mainly on sweet gum, walnut, birch and oak. The papery cocoon is usually found on the ground.
Imperial Moth. Females are sometimes as large as 5.5 inches wing tip to wing tip, while males are usually much smaller. The wings are yellow with pink spots and pink wavy lines. The caterpillar is usually green, but may be tan or brown. Along the sides of its body are white spots outlined in black. This caterpillar feeds on oak, maple, pine, sweet gum, and sassafras.
Sphinx Moths. Adult sphinx moths are powerful fliers. Their slender wings have subtle and intricate patterns. The Pandora sphinx moth is a distinctive olive green color with black and pink markings. The caterpillar is green or reddish-brown with large, striking white spots along the sides of the body. All sphinx moth larvae have a horn-like appendage at the rear of the body. When the Pandora sphinx larva is half-grown, it loses its rear appendage and acquires a glassy eyespot in its place. These caterpillars hold their bodies in an erect sphinx-like position, hence their name. They feed mainly on grape and Virginia creeper. Most sphinx moth caterpillars burrow into the ground to pupate. Their mouthparts develop in a distinctive handle-like structure.
Royal Walnut Moth. This is the adult of the frightful looking hickory horned devil. The moths have orange painted front wings with yellow spots, and can be up to 5.5 inches tip to tip. Their caterpillars feed on hickory, sumac and sweet gum.
CONTROL: Adult moths feed on flower nectar and other plant juices but never damage the plants. Caterpillars of giant moths are usually found alone or in small numbers and rarely cause economically important damage. In rare cases treatment will be required; check the Virginia Pest Management Guide for current insecticide recommendations.
Revised by Eric Day. Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0319.