Scientific name: Aricia agestis
Although one of the "Blues" both sexes are brown on the uppersides with a band of orange spots at the border of each wing. The underside has the typical "blue" pattern of a greyish/brownish ground colour with black spots outlined in white and a row of orange spots along the border. Like other blues it is common on the chalk downlands of southern England but will also use other habitats such as woodland clearings, coastal grasslands and heathland.
Common Rock-rose is the favoured foodplant on Calcareous soils. In other habitats Dove-foot Cranesbill and Common Stork's-bill are used and possibly other Geranium spp. as well. The larvae are green with a pale line along each side and always attended by ants.
There are two broods a year with adults on the wing in May and June and again in late July till mid September
Information and photograph courtesy of en. wikipedia.org