Accidentally cut this off my Japanese Maple today - did not see the cocoon on it. I am afraid to throw it in the compost pile because it might still be alive. It seems to be all in piece, with no openings anywhere. I am not butterfly/moth savvy. I am in zone 6a. I have no idea when butterflies/moths hatch here. Is this still viable? If so, if I put it in a jar until it hatches, do I need to give it air? Is it a butterfly or moth?? Any info is appreciated. Thanks.

It is most likely perfectly healthy.

Cocoons need air, a sealed jar is a bad plan. A jar in the house is most likely also too warm to keep the cocoon healthy. I would put it back into the Japanese maple. Tuck it into a crook or a lower branch where it will be a little sheltered and less likely to be picked off by a bird.

I looked at some photos on Google, and am now worried it may be a bagworm cocoon. Anybody know?

Unfortunately, I have no idea on the id of the cocoon....

Go put it back in the tree; pin it to another small branch with a clothespin. Then watch it to see what you get It kinda looks like a swallowtail crysallis, except it doesn't have a silk string holding the upper part secure. But maybe that got lost.

definitely a bagworm! Don't grow it, destroy it!

thanks!

Your welcome!