OK, I was bad and you can all beat me up verbally later. I got impatient, figuring the cocoon was no longer viable and I opened it. Well, started to open it. I breached the outer cocoon and had just started to expose the pupa when I suddenly got that sense of...weight that you mentioned before. This felt decidedly heavier than the other empty cocoon and pupa. And I stopped right there! So - here I am with a baby on my hands and I don't know what to do with it. I have rigged a cage as you can see in the pic, and the thing is presently in a room by itself with fresh air coming through the window. That's the closest I can approximate to same conditions of temperature and humidity. It will be slightly warmer than it was outside, but not by much. Without the lights on, the room is in about the same lighting conditions as the shady area it was in before. I've changed the orientation of the cocoon somewhat when I attached it to the cage - is that a problem? And what do I do next??? Will it need misting or anything since it would be getting that outside? And once the moth starts to emerge, which hopefully it's still going to - how long a process is it till it's ready to be set free? Is it more likely to do this during the day or the night? I don't want to stress it out by being caged and I don't want to miss taking a pic either. :) - Alex

Sounds like a plan. What are your plans for the book of sketches. Have you removed pupa before and had them be ok? K

"polyphemus geometrid" is a strange phrase, almost an oxymoron like "lead balloon". Your moth cocoon is probably a polyphemus saturniid. Geometrids are typically smallish, dainty moths. You should probably leave the cocoon alone. I think the pupa emits some liquid to help escape the cocoon when the time comes. The storage temperature will determine when the moth will emerge. The most important thing is to put the cocoon in a very large container, a cubic foot is not too large, and put in sticks or objects the moth can mount to open and dry its wings. Otherwise the wings will remain a crumpled mess and the moth cannot fly. I had one in the garage in a box with some sticks and a screen over the top some years ago and it emerged just fine.

From your pics, it is not obvious how big the antennae are but I lean towards them being too big for a female. Plus the fact that the moth flew off early during its first night indicates it was not a female.