Hyalophora cecropia, the Cecropia Moth, is also known as the Giant Silkworm Moth or the Robin Moth. It is the largest moth found in North America and spreads from the East Coast to the Rocky Mountains. This moth has a massive wing span of 5.5 to 6.0 inches, but they fly only at night and are attracted to lights.
Cecropia Moths have just one generation each year, with adults emerging in the spring. They do not have a mouth and never feed, only living for a week or two – just long enough to lay eggs for the next year.
Each female can lay more than 100 eggs, which she deposits in small batches on the underside of leaves. They are oval in shape, somewhat flattened and buff to brownish in color. The eggs hatch in about one to two short weeks.
The young larvae are black but as they grow they turn yellow. Full grown larvae are more than four inches long. They are very colorful. They are light green in color with a bluish tint. Their back and sides are covered with spiny tubercles (bumps) that are red, yellow and blue.
When fully grown the larvae spin a large silk cocoon that is yellow-brown in color. It is attached to leaves and stems. They pupate and spend the winter inside the cocoon.
The color pattern at the edge of the front wing mimics a snake and aids in protecting this moth from bird predators.