Fran, I think the organic method (apart from squashing any you find!) might be squirting with Derris dust to kill them. I have had problems with gooseberry sawfly larvae in the past & although they strip the leaves the bush does recover & the fruit are O.K. they just get so annoying!
P.S. Just noticed you can get Bio Liquid Derris now to spray with instead of the powder, Derris is used by lots of 'organic ' gardeners.
PPS. Rat says gooseberry sawfly only attack gooseberries but they also ate my redcurrant, I saw it with my own eyes & Doctor Hessayon's 'Garden Troubles Expert' book says they attack gooseberries & currants.

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Into every life a little rain must fall.