Dusky Large Blue
Maculinea nausithous
The first 8 pictures show several (but probably not 8!) different individuals photographed in Switzerland in July 2006.

Note that this is a female, laying eggs

The picture below shows the first dusky large blue I ever saw, in Switzerland in July 2001

This is the habitat - wetlands with greater burnet.

I first came across a colony of Maculinea nausithous whilst looking for a different butterfly - and it quite took my breath away. This is an extremely rare butterfly. Unfortunately, not a single individual has ever deigned to show me the upperside of its wings at rest - I don't think they do this! However, in flight it was possible to tell males and females apart, the males looking very dark but with a leaden blue overtone. I have since been back to the same site and in July 2006 found very many flying in a localised region of the large expanse of greater burnet, the foodplant of the butterfly and the plant in all the pictures above! I don't think I have ever seen a dusky large blue settle on anything other than this plant.