Hyalophora cecropia, the Cecropia Moth is also known as the Giant Silkworm Moth and as the Robin Moth. It is the largest moth found in North America. It is found from the East Coast to the Rocky Mountains. This moth has a wing span of 5.5 to 6.0 inches. They fly only at night and are attracted to lights.

Cecropia Moths have only one generation each year. Adults emerge in the spring. They live for only one-two weeks. They do not have a mouth and never feed. Their soul purpose is to lay eggs and produce the next generation.


Each female can lay more than 100 eggs. The eggs are deposited in small batches on the under-side of leaves. They are oval, somewhat flattened and buff to brownish in color. The eggs hatch in about one -two 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.