Thanks Martin. I didn't immediately recognise it (altho' it looked familiar) but I've reared these before as you'll probably remember and it eventually dawned on me what it was.
You probably missed the hailstones too Dave! Yes, I mentioned to Andrew that I too had seen 2 males engaged in this behaviour but it was several years ago and I can't remember if the proboscis was involved. I shall need to check my old photos and pay more attention in future.
Thank you David. The wild eggs I checked have hatched but I can find no sign of the larva yet.
Cheers Trevor and well done with the mating pair. It has been a few years since I saw that ..... and this should probably be in your diary but I think you captured the Brimstones way better than I did. Today I found my first (quite large) tick biting me which I imagine came from BB - possibly the only downside to that venue, apart from the traveling distance!
I appreciate that very generous comment Paul - even if I don't quite believe it
Thanks Andrew. I am looking forward to seeing your images of the Wood Whites. You were right - I had reared those larva before which is why it looked so familiar. I probably told you when we were looking at SSB's that for the last 3-4 years I have searched for their larva. Well, yet again I have failed miserably, despite looking in 2 completely different environments (at frequent intervals). However, whilst searching I have come across a number of interesting critters including this larva which I believe is the Garden Tiger Moth - tho' as usual I could be totally wrong. It was a very attractive creature but my word, I've never seen a caterpillar move so fast

I honestly didn't know they could move like that:
A lot of the heather at the Broxhead site where there were a number of SSB's last year seems to be dying off - not sure why this is or whether it will impact on this year's brood as they seemed to favour this patch for egg-laying: