The Chalkhill Blue is I think, one of the most striking in colour and pattern of the small Blues.
Its main population is restricted to Southern England, it can only be found in one or two places higher up the country. Fortunately one of those places is quite close to my location in the Northern part of East Anglia and its one of my 'Target' images each year. I am pleased to report that when I shot these images, I observed a considerable number of Chalkhills at that location.
Although both relatively small as butterflies go, the males are larger than the females with a wingspan of 38mm. They can be found on the wing between mid July to mid September.
The female Chalkhill Blue as shown below can at times be confused with the female Adonis Blue and close comparison is necessary.