Bug of the Month March 2014: Polyphemus Moth Cocoon

Subject: Weird pod I’m hoping will hatch a wonderful creature
Location: Brooklyn, NY
March 1, 2014 2:38 pm
Hi Bugman–
Yesterday my daughter and I found this strange pod under some oak trees in Prospect Park, Brooklyn, NY. It looks like some kind of cocoon–it has an imprint of a leaf on what seems like a hardened foamy surface. We’ve had a lot of storms lately so all kinds of things have been shaken lose from trees. It’s about two inches long.
Also, if it is some kind of cocoon, how should I care for it?
Signature: Carol Vinzant, editor, animaltourism.com

Cecropia Moth Cocoon
Cecropia Moth Cocoon

Dear Carol,
If it is viable, this Giant Silk Moth Cocoon will produce a gorgeous once the weather warms.  Keeping it indoors with warmth due to artificial heat will cause it to eclose early and result in a sterile death without reproduction. Giant Silkmoths only live long enough to mate and lay eggs, and they have atrophied mothparts, so they can’t even eat.  We believe this is either the cocoon of a Luna Moth or of a Polyphemus Moth.

Wow, that’s fantastic! I can’t wait to see what happens.
I didn’t understand from your message if I should keep it indoors or out. Right now it’s in a sheltered area with outdoor temperatures. When do they hatch?
Carol Vinzant

We don’t know what the ambient temperature needs to be before eclosion will occur, but we suspect it will hatch in the spring.

Great, thanks for all your help.
I blogged about the cocoon and your answer here: http://animaltourism.com/news/2014/03/13/what-to-do-with-cocoons-falling-from-late-winter-trees
Carol Vinzant

Thanks for the kind website plug Carol.

Update:  June 19, 2014:  Cocoon Hatches into Polyphemus Moth
thanks again for your help on this. it hatched the first week of june! it was a polyphemus. we released it back to the park.
Carol Vinzant

Polyphemus Moth
Polyphemus Moth

2 thoughts on “Bug of the Month March 2014: Polyphemus Moth Cocoon”

  1. Hi Carol,

    Outside is perfect– means it’ll hatch when all the wild Polyphemus are hatching. Make sure it’s in a container that gets the benefit of the rain, but won’t let raccoons or what have you get in. I lost a crop of Poly cocoons to raccoons one summer, it was a travesty. Good luck, can’t wait to see updates!


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