I have a problem with my cannas and some of my bananas. Some pest is inside the rolled-up leaf and eats through before the leaf emerges. The leaf is a brownish color at the base of the leaf, with virtually no strength, and it seems soggy. The brownish color does not take over the leaf...just a three inch area at the base. There are also round holes chewed through the leaf before it unfolds, which becomes a row across the leaf when it unfolds.

I have tried malathion with no success, and yesterday I spread Bayers Slug Control around the base of the plants.

Does anyone else have this problem, or know how to remedy it ?