Polyommatus erotides

Polyommatus erotides is a  butterfly found in the  East Palearctic (Saur, Altai, Siberia, Transbaikalia, Mongolia)  that belongs to the blues family.

Taxonomy
Formerly a subspecies of Polyommatus eros.

Description from Seitz
erotides Stgr. (80 d), from the mountains of Southern Siberia, is a large, blue-green male form, with broad black distal margin to the forewing, into which the deep black veins merge.

Biology
The larva feeds on Fabaceae.