Bug attack on feathers???

Any entomologists out there? In my earlier post on “something” attacking a cape, I described the casing. A guy at a university said to keep a couple and he’d see if he could ID them.

Well! Yesterday I decided to shoot a couple of pics of the creature and as I was doing it the larvae actually started to emerge from the casing! If anyone can identify it I would like to know what it is.

I’ve attached a picture. The larvae is emerging from the right side of the casing on the dime.

Thanks - Keith