Grass hoppers. If you trim the leafs there won't be anything left. You'll just be finishing what the bugs started.
We need to see more of the plant to know how to save it. Grass hoppers don't like DE. First thing I would do is apply it. You can dust it on, but that's a messy way. Better to mix it with water 4 tablespoons to a gallon of water and spray. Then I'd be pulling weeds even befgore the DE got dry.