What is this cocoon?
This is a very good thing. It's a very large cocoon, because inside is one of the Giant Silk Moths getting ready to hatch. There are several species that live in Maryland. The giant green Luna Moth is one of them. But this one, because we see that the cocoon is attached lengthwise along the branch, is probably a Cecropia Moth, a huge beauty with orange, brown and black markings. They are night flyers and are attracted to lights. Enjoy.