The Adonis Blue Butterfly.
The sight of an Adonis Blue male is something to experience.
It would soon become apparent once you had seen it, that it was the species and not any other. The bright electric blue of the upper wings flashes as it flies low across the grass.
Finding and photographing the Adonis I would place on a par with that of a Purple Emperor butterfly, which I have experienced.
It prefers South facing chalk down slopes.
It is difficult to reproduce the exact colouring in a photograph, but I hope I have done it justice.