Posted: 13/06/2016 at 20:37
I also use a spray of diluted neem oil .... it is totally organic. I've had no gooseberry sawfly problems for the last 5 years ... and great crops of berries.
See this link for further info.
and this one for how to make it.
I use it as soon as growth starts in April and I drench the foliage. Any spare solution goes onto the soil below as the earthworms are supposed to love it. I repeat spray every few weeks.
Neem is best used preventatively .... but will work on pests that have already arrived. It does not hurt beneficial insects. Only chewing and sucking insects are affected. The main reason is that insects need to ingest the neem oil to be affected, and beneficial insects don't eat your plants. However, you can still kill beneficial insects if you smother them with neem oil, so I tend to spray late evening to be safe.
It does stink a bit ... but is easy to mix up and apply.
I got mine off ebay .... wasn't expensive for a big bottle which will last ages. At room temperature it is solid, but goes liquid again within a couple of hours in the airing cupboard.
Worth a try .... also seems to work well for lily beetle and aphids.