Polyommatus boisduvalii

Polyommatus boisduvalii  is a  butterfly found in the  Palearctic (East Germany, Czech Republic, Poland, Southern Europe, Siberia, Kazakhstan Altai) that belongs to the blues family.

Taxonomy
Formerly a subspecies of Polyommatus eros.

Description from Seitz
The males of the South Russian form [ of eros] boisduvalii H.-Schaff. (80 d) have again a different blue, being paler, purer, brighter, the outer margin of the forewing is broadly black, the black veins in the apical area of the forewing being thin but sharply marked.