Cecropia Moth

This colorful moth is a Cecropia or Robin Moth (Hyalophora cecropia), they are the largest moth in North America and may have up to a 6  inch wingspan. They are members of the family Saturniidae, which are the giant silk moths. They should not be confused with the silk moths used to produce silk for human use. The one pictured here is a female and was brought to me by a good friend. His girlfriend found it by her porch light and did not know what it was, I was able to identify it for them and he gave it to me. I plan to release her and see if she will attract the attention of a mate. Tonight is far too cold and rainy, so I will hold onto her for one more night and see what tomorrow brings. She is already laying eggs in the shoebox she is in.

Cecropia's have long been my absolute favorite moth, even over the much favored Luna Moth. The color of the cecropia is so unique, with shades of chocolate, burnt orange and tan. The body is banded with orange, brown and cream stripes. Females have a large abdomen for egg production, and males have obscenely feathered antennae to detect the pheromones (Chemical perfume) that the female emits. The male is capable of smelling the female from great distances, possibly up to a mile or more away. The one pictured here is fanning her hindwings, I assume to spread her scent better, making it easier for a male to find her.

Once mated, the female will lay her eggs near host trees. Typically they choose maple trees for their host, but it is also common to find them on other trees like Birch, Wild Cherry, Box Elder, Plum, Alder, Apples and Willow. The eggs will hatch in about 2 weeks and the newly born caterpillar will eat its eggshell. The small caterpillars will feed in communal colonies, until they are larger, then they become solitary.

(Thank you Linda Williams for providing this amazing image of the caterpillar. Three instars are shown here.)

It takes them approximately 2 weeks  months (thanks Linda W. for catching my faux pas) to reach full size at which time they will find a dark secluded place to attach themselves to a branch or stick and form their cocoon. This cocoon will overwinter and the adults will emerge the following spring, like the one pictured here. The adults do not feed, in fact they do not have mouth parts, all the nutrients they need are gained in the caterpillar stage. All their energy as adults is used up looking for mates and laying eggs. Consequently their lifespan is short at less than one week, typically around 4 to 5 days.

These moths are attracted to lights at night and are hugely prized by insect collectors for their large size and outstanding beauty. I hope tomorrow nights weather is much improved so that I can place her outside and see if she attracts a nearby male. I would love the opportunity to photograph their interaction, and then see her off to live long enough to lay her eggs and secure the continuation of her species.