Maybe he needs some WD-40? Oops, I was channeling Jeff for a sec there.

Very strange, and I've never seen that before. Maybe the "dry" part you're seeing is actually a tiny piece of skin that stuck to the osmeterium during the molting process????? Can you see it closer if you use a magnifying glass?

Susan

Does sound really odd and unusual. I have never seen it before. Poor thing.

This happened to one of my last BST cats, maybe at around 4th instar. The osmeterium was always sticking out, not fully extended, but it appeared the poor guy couldn't fully retract it either.

I worried about it, of course, but continued tending to the cat as best as possible. He (or she?) ended up pupating AND eclosing normally. That butterfly ended up being the smallest BST released this year, however, so maybe it did affect it somehow?

My choice for things stuck is to spray them with a mister (water). Water loosens many things. I've used a mist of water to help a monarch caterpillar get its face mask off that got stuck when it molted. I've used a mist of water to loosen skin that was stuck around a moth caterpillar's body. The skin needed to come off so the moth could continue eating. I've used a mist of water to carefully pull off skin that was stuck to the tail section of a chrysalis after pupation.