The gooseberry sawfly larvae also live on the leaves of Solomon's Seal. If you have any of that, make sure it is planted well away from your gooseberries, because they will move from one to the other (both directions) and strip both.
If you don't know Solomon's Seal, it is also called Polygonatum It is about 18 inches tall, blooms in April-June, and looks a bit like a large version of lily-of-the valley, but with the flowers hanging from the axils of the pairs of leaves, and without the lovely scent. Very useful in shady places, under trees etc. I'll look for a photo