Rosy Maple Moth

Dryocampa rubicunda
Wednesday, July 14, 2010

Rosy Maple Moths, although relatively common here, are one of the more beautiful moths in this area. They are present across much of eastern North America, extending north into Quebec, south into mid-Florida and the Gulf Coast, and as far west as Texas.

Typically, D. rubicunda have a wing span of 3.4-5.2 cm. Their wings are creamy yellow or white, with rosy pink markings on the margins and bases of the wings. Their coloration, however, is extremely variable; in some the wings may be pink with small slivers of yellow; in others the pink markings may be less noticeable, or even gone. Moths with very few pink markings are classified as the subspecies alba, and usually occur in Missouri. Their heads and bodies are typically furry and yellow; their antennae and legs are red-pink and the former are feathery. Antennae tend to be larger on males.

The caterpillar, often called the Green-Striped Mapleworm, is, as the name implies, green with pale blue-green stripes. It has two large black horns on its second segment, and smaller horns on its lateral sides all down its body. Its head is orange-brown and smooth. The fully grown caterpillar can reach the length of 5 cm.

Adult female moths lay clutches of 10-30 eggs on the underside of the leaves of a host plant, normally maple or oak. In about two weeks, the eggs hatch, and the caterpillars begin feeding gregariously on their host plant. During the first three instars (a developmental stage, marked by a moult), the caterpillars feed in groups, massed on the leaves of their host plant. During the next two instars, the caterpillars mainly feed alone. At the end of their 5th instar, they climb down the tree and pupate in shallow underground chambers. The pupae are dark and elongated, with small spines. They pupate overwinter. There is one brood in the north that emerges and mates in May-August, and two broods in the south from April-September, and as many as three broods in the deep south from March-October. The trend here is that the moths emerge in the warm season, and how long the warm season is influences how many broods are born. When it is the right time, the adult moths emerge in the late afternoon and mate in the late evening. The females release pheromones, which the males pick up with their antennae. At dusk the next day, the females begin laying eggs on the underside of the leaves of the host plant. The adults never feed—they retain all their energy from what they ate as a caterpillar.

This moth was found on a lamppost on the lawn, where it was likely attracted the previous night. These moths are primarily nocturnal.

Article by Hazel Galloway

Photos of this organism can be found here, courtesy of