Buckinghamshire, United Kingdom

Rose sawfly?
Yesterday I picked off two grubs feeding on the leaves of one of my rose bushes. I'd never seen any like it before though they were about the same size as gooseberry sawfly. These were orange tipped top and bottom, the body being a pale grey with fine black stripes. I didn't think to photograph one until after they'd been squashed.
I googled images but there were so many I finally gave up though I did discover that there was such a thing as rose sawfly.
Given the description above can anybody tell me what I squashed please?

• 17 Aug, 2016