This is a dark blue pansy, Junonia oenone oenone, at Hoedspruit, Limpopo, South Africa yesterday afternoon. I have to look for more of these, they are quite pretty when you see them flying around the yellow flowers. Look at them full screen to see the exquisite detail.

The upper surface of the hindwings is black with white markings on the outer edge, and a characteristic large metallic-blue spot. This blue spot is smaller and more a dull purple in the slightly-larger females so I guess these photos are of a male.

The male Blue Pansy spends a lot of time chasing other butterflies that enter its space.
The larvae feed on a variety of plants, including Adhatoda densiflora, Mackaya bella, Justicia natalensis and Asystasia (A. gangetica), Isoglossa, Pualowilhelmia and Ruella species.