Cecropia Moth (Hyalophora cecropia)

by Michael Holmes

The largest moth in North America, the Cecropia Moth is a spectacular member of the insect world. With a wingspan of 12 to 15 cm, its size alone is remarkable. However the Cecropia Moth also sports a magnificent display of colour and pattern. Its body is covered with a fuzzy coat of red-orange, brown and white. The wings are decorated with gradations and stripes of grey-brown, red-orange, and white, with a crescent-shaped marking on each wing.

The distribution of Cecropia moths on this continent is widespread, however sightings remain a rare pleasure. This is mainly due to the Cecropia's nocturnal habits. The glow from porch lights and streetlamps attract these moths and this is where most sightings occur.

On June 9, a pair of Cecropia Moths were observed mating on a shrub in front of Unit 19. Kathy Middleton had placed there a silken cocoon, from which emerged a female Cecropia. Soon after, the moth attracted a male and they began to mate.

Male and female moths can be told apart by their antennae. Whereas the antennae of a female are narrow, a male has broad feather-like antennae which help him sense a female's pheromones (chemical signals). The powerful pheromones released by a female can be detected by a male a mile away, which is important because a Cecropia Moth cannot afford to be coy.

Despite its remarkable size and beauty, the life of a Cecropia moth is fleeting. The adult moths lack mouthparts and as a consequence survive off their limited reserves. This gives them just enough time to find a partner and reproduce. An adult only lives about two weeks, shorter if it is highly active and burns energy quickly.

The Cecropia Moth encounters numerous threats throughout its life. The caterpillars make ideal hosts for parasitic wasps and flies. Birds and squirrels can easily overpower the vulnerable caterpillars. Pesticide use is also thought to have taken a toll on the Cecropia Moth population.
Caterpillars of the Cecropia Moth feed on the foliage of a number of trees and shrubs, including cherry, birch, maple, willow, apple and elderberry. Cecropia caterpillars are large and green, with colourful tubercles protruding from their bodies.

If you see one of these impressive caterpillars, or an adult moth, do not disturb it. Instead, take time to enjoy the rare sight of one of North America's most magnificent insects.