Opening a Polyphemus moth cocoon

The REAL title to this post is “Opening a Polyphemus moth cocoon or, what to do when it’s cold as f*$%.”

A few weeks ago we found a random cocoon without it’s outer casing. Judging by how it was attached to the branch, I assumed it to be Hyalophora cecropia – a Cecropia moth. I also assumed he was dead!

Silly assumptions.

Today is the coldest day so far this winter, so there was going to be no outdoor exploring for this gal. What better activity for a housebound day than silk moth cocoon dissection?!Cutting open a Polyphemus moth cocoon, Dirty Botany

Preparing for dissection!

Polyphemus moth cocoon close up, Dirty Botany

At a close look, you can a portion of a leaf that was glued in place with silkworm saliva. Yum! And cool. This cocoon feels surprisingly sturdy, and if you give it a little shake you can hear the pupa rattling around inside (the dead pupa, again I assumed).

Using scissors to cut open Polyphemus moth cocoon

That outer shell is actually quite hard – once I broke through with the scalpel it was actually easier to carefully cut it with the scissors. Just be careful not to nick the moth pupa inside!

Opened polyphemus moth cocoon with visible pupa, Dirty Botany

And he’s open! I have to admit….when I first opened him up, he wriggled. And I screamed.

Did I mention I thought he would be dead?!

You can see the cast off skin of the caterpillar balled at the bottom. Kind of like how socks end up at the bottom of my bed by morning, I suppose.

HOW COOL IS THAT.  And how cool is it that I managed to not say anything stupid during the video.

He’s very much alive. He’s very much a HE. And he’s Antheraea polyphemus – a Polyphemus moth, which is awesome because I have yet to get a Polyphemus to emerge! The fact that he’s alive now bodes quite well for my chances this year! (check out last year’s moth emergence in this post!)

Antheraea Polyphemus moth pupa, Dirty Botany

Per THIS article from the University of Florida, you can tell this is a male because the antennae touch at the bottom, and because there is not a notch at the bottom of the pupa.

It’s pretty awesome when an afternoon project goes even better than planned! I can NOT wait to see this guy emerge in the spring! Expect a Polyphemus moth post in the spring!



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

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4 thoughts on “Opening a Polyphemus moth cocoon

  1. Jason Reply

    I did the same exact thing as you with a Antheraea polyphemus, cutting open the cocoon to find it alive. However, I am in Chicago and its August….What do I do? Will it survive?

  2. queensny Reply

    I have a polyphemus moth in my garage that i found last August or September and it cocooned shortly after i put it in a cup with a branch and leaves. It overwintered and its may now and i feel and hear it moving around inside. I moved it into a tank with sticks to climb and a mesh like top. I wonder when its going to come out.

  3. Danielle Reply

    What happened to the being inside? Did you kill it by opening it way too soon?

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