Polyommatus icarus - Common Blue

Polyommatus-icarus-common-blue | PTKbutterflies
Polyommatus-icarus-common-blue | PTKbutterflies
Polyommatus-icarus-common-blue | PTKbutterflies
Polyommatus-icarus-common-blue | PTKbutterflies
Polyommatus-icarus-common-blue | PTKbutterflies

This is the most common and widespread Blue butterfly in Europe. It's violet blue is beautiful when fresh and it can make for a very beautiful butterfly photo.

The females carry a variable amount of blue as shown here. 

In 2018 I found the Arctic subspecies to be very different, without the forewing cell spot, and generally much less well marked.

Polyommatus-icarus-common-blue | PTKbutterflies
Polyommatus-icarus-common-blue | PTKbutterflies

The butterfly images below are from high in the Arctic circle, notably and consistently  different...