Jeff zone 8 N.C.

It's not a disease but is an insect infestation. You will probably need to use some type of spray multiple times over at least a couple of weeks. I hate insecticides so do not know what to recommend but if no one else answers on what to use then your local or state Agriculture Department can tell you. Or you could just get a broad spectrum insecticide. For myself I would use a natural product. I have never had to spray my banana plants so I again do not know what to tell you to use but the internet should be able to help. If your damage is severe and you do not have much growing season left you could just chop it down and bag and take away the plant so the bugs are gone for next year.. No leaves mean nothing for the pests to eat.