Bundles of Awesomeness: Giant Silk Moth Cocoons

Giant silk moths, family Saturniidae, are the largest moths in North America. Here in New England we have four noted species  – Antheraea polyphemus (Polyphemus moth ), Callosamia promethea (Promethea moth), Hyalophora cecropia (Cecropia moth), and the most famous, Actias luna (Luna moth).

All four species build their cocoons in the fall to over-winter, and then hatch in late May or early June in what is called their “flight.”  After hatching, they live only long enough to lay a new generation of eggs.

Cecropia and Promethea Moth Cocoons

This is the time of year to find these cocoons! With no snow and no leaves, it is not too difficult to see Cecropia or Promethea cocoons. Lunas build theirs on the ground buried under leaf litter so they are not generally seen in the winter.  We have not actually found a Polyphemus yet, so we’ll call that one difficult to find, too!

We had collected two Cecropia and one Promethea so far this spring, and I was pretty happy with that.  Walking in the yard yesterday, though, I thought I noticed what I thought might be one on a forsythia (argh! not native, I know, I know, I know.) bush. It was!  Callosamia promethea moth cocoonAs as I got closer, though,  I noticed another, and another, and another….

Forsythia bush with ten Callosamia promethea cocoons. Jackpot!

Don’t mind the cheesy Photoshop arrows. I didn’t want you to miss any!! That ONE bush has ten cocoons! Jackpot!  I don’t think of the giant silk moths as Pine Barren moths, but apparently they don’t mind the pine barrens as long as there are delicious forsythia bushes around! They are all coming inside to the safety of our bug tank…we shall see what the hatch rate is. The rate has declined significantly in the last few years thanks to Compsilura concinnata, a parasitic tachinid fly that was introduced in 1906 by the Department of Agriculture to stop the spread of gypsy moths (another introduced species….we’re doing a good job, huh?).

Don’t worry. You’ll get updates. And more exciting pictures!


the dirty girl at dirty botany
Head dirty girl at dirtybotany.com!
Bug worshiper.
Slime mold fanatic.
Macrophotographer in training.

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