You can't really permanently prevent this problem - information and treatment advice here

https://www.rhs.org.uk/advice/profile?PID=196

Thanks, although I would have prefered not to use chemicals...lets hope I can spot the little blighters next year before they do too much damage.

I had the same problem on one of my roses too. I picked off those caterpillars I saw and hope that's the end of it for this year. I wonder if it was the weather conditions because I haven't had this problem before.

Me neither Arbuthnot. I'm hoping I don't get it again either...fingers crossed for next year.

I did spray some of the leaves with a bug killer too but didn't want to overdo it when the blooms were open.

So I understand.