I have some hosta I planted this spring, Golden Tiara. It is being eaten up. I can't find any worms on the plant so I am inclined to think it is slugs. Some of the leaves have small holes others have chunks missing along the edges, some of them up to half or more of the leaf is gone! This happened in the past week. How do I tell if it is worms or slugs and if I spray them lightly with sevin dust will that deter slugs? They are mulched around with hardwood mulch planted under a Hemlock tree. Please help before they disappear altogether!