Just saw one of these on my allotment
although I couldn’t get a photo with just my mobile. It says on that link that it’s not that rare, but I don’t remember seeing one since childhood, and that may just have been in I Spy Butterflies.
I also saw a marbled white
a couple of weeks ago in my polytunnel, which again I’m not sure if I’ve ever seen before. I did get a shot of it, which I’ll post when I get home.