Porkpal: "Rose Chafers" appears to be a common name or a synonym here for Rose Slugs. It just depends on what nursery you go to and who you ask. I've been "guilty" of interchanging the names myself.
Whatever "they" are, the usually appear here around mid June and they chew a lace-work pattern in rose foliage. You can see their tiny black droppings under the damaged foliage. Yhe damage they cause aint pretty.
