www.ukbutterflies.co.uk

Yesterday was a special day for me in my butterfly garden, it being the first time during a lifetime interest in butterflies, that I had witnessed a pair of Brimstones mating. It was instantaneous - she was flying along minding her own business when he plummeted out of nowhere, forced her to the ground, and they immediately paired in low vegetation. No courtship! Normally mating occurs high up in a bush where they are safely concealed. Amazingly, only minutes before I had witnessed another female actually laying eggs on alder buckthorn.

Nice sighting, Phil. Only seen this once myself, although the preamble was similar to that in your garden, i.e. no real courtship whatsoever.

I guess nomadic species like these can't afford to be too choosy.