The first four pictures below were taken in the Val d'Aran in July 2005

Male (behind it are a small skipper and a northern brown argus)

Same male. In this and the shot below the blue with it is an Eros blue.

Note the bold white streak reaching almost the length of the hindwing.

Sadly, this silvery argus was crushed by one of the cars that regularly pass along its mountain track.

The silvery argus is a special butterfly. It is local and generally uncommon in the Alps and Pyrenees and is most easily found by searching areas where blues gather to take minerals, as in the pictures above. This means that the male is most commonly seen (I have never seen a female). The female is dark brown above, without the blue/green colour.