[weeeed]

I read all sorts of rubbish but this did my old hippy heart good!  Nothing against nuking weeds but if it's possible to be organic and get a result go for it I say. White false Helleborine which is very poisonous        can be dug up and the roots powdered and used to kill sawfly.  Hope this helps, please let me know the results. :idea:

[Trillium]

Never tried it myself, but it it's that poisonous, I'd be very leery of using it. I had to resort to a chemical insecticide this year for my roses, but 1 spraying did the trick and I don't think I'll have to do it again. I sprayed in the evening after all the bees left and by morning all was safe. I asked specifically about this concern before I bought the product. Sometimes you just have to go with chemicals, but not regularly.

[milkman]

the entirely organic solution is to underplant your gooseberries with poached egg plant - limnanthes douglasii - it self seeds very easily so 1 packet of seeds should be all you need.  This encourages lots of hover flies which feed on the sawfly thingys, problem solved - this is the answer according to mr b. flowerdew and works for me.