Twice when taking photo's I have spotted what I think maybe adult Gooseberry Moths sunning them selves on the bushes. They are very wary and are off before the camera shutter operates.
The second hatch has taken place and it is hand picking time for the little green caterpillars. Several dropped to the ground and were dragged off rapidly by ants.
Spurred on by a comment from joebangles I looked up the moths as opposed to flies that attack gooseberries. The Goose or Magpie Moth and the V moth use the gooseberry as a food plant. Mine is not either of those and may even be innocent.
I am as guilty as the next man of calling all munchers of my bushes Sawfly. I think many illustrations of Sawfly Larvae may well be wrong, they are showing attacks by moth caterpillars.
Caterpillars characteristically eat round the edge of a leaf making it smaller and smaller. Sawfly start eating from a hole which they elongate and enlarge.