What Do Hyalophora Cecropia Caterpillars Turn Into?

The stunning appearance of a large adult cecropia moth takes many people by surprise.

The cecropia moth, Hyalophora cecropia, lives in most of the United States east of the Rocky Mountains. As a member of the family Saturniidae, which includes other large, showy silk moths, members of this family are sometimes called royal or regal moths and sometimes giant silkworms. The cecropia moth is the largest moth throughout most of its range.

Larvae (Caterpillars)

Cecropia moth caterpillars grow to be fairly large and typically go through five instars before pupating. The third through fifth instars look similar; large, bright green or sea green bodies, prominent protuberances along the larva's back. Sometimes the full-grown larvae appear to be green with a hint of fluorescent blue. The protuberances along the body are bright blue, yellow, orange and red; each protuberance has black spines. In the fifth instar, the caterpillar can reach up to 4 1/2 inches long and 3/4 inch in diameter.

Adults (Cecropia Moths)

Reaching up to a 6-inch wingspan, although size greatly varies in adults, adult cecropia moths are showy and admired by collectors and lepidopterists alike. The wings are brownish in color with red on the forewing. The hind wings show prominent red and white crescent-shaped spots, although these spots are visible on all wings. The body of the moth is red and white; red, furry legs add to the moth's colorful appearance.

Life Cycle

Adults emerge from their cocoons in mid-spring; you may see them as early as April in some areas through the middle of summer. When she emerges, the female is full of eggs waiting to be fertilized by the male. A male and female will mate for the remainder of the day once they find each other; the female then goes to lay her eggs that night. In late summer, the full-grown larvae spin dark gray or brown cocoons approximately 4- to 5-inches long and 1- to 2-inches wide; the cocoon is attached to twigs or between branches. The cecropia moth then pupates over winter.

Economical Information

Although the larvae feed on a variety of ornamental plants including cherry, apple, plum, lilac, willows, birch and maples, they rarely cause significant damage because of their low populations in any given area. Sometimes, though, you may notice defoliation on young, small transplants.

Because of their large size and striking appearance, many people try to raise cecropia moths. To raise these moths, place a caterpillar in a bug-safe container with a preferred food source. Once the caterpillar has spun its cocoon, transfer the container into the garage or other area where the temperature mimics outside winter temperatures. Unless you have male and females, observe the moth for a day or so and then release it.

References

• Iowa State University; Cecropia Moth; 2005
• University of Kentucky; Saturniid Moths; Ric Bessin, Extension Entomologist; 2010
• Cornell Cooperative Extension of Chemung County; Cecropia Moth; Carolyn Klass; January 1974
• University of Florida; Cecropia Moth, Cecropia Silk Moth, Robin Moth, Hyalophora cecropia Linnaeus; Geoffrey R. Gallice; July 2010

Resources

• Kansas State University Extension Johnson County: Cecropia Moth
• University of Wisconsin-Madison: Treenuts 2K; Raising Cecropia Moths;