|Hi Stefano, thanks for helping !
But im not sure this is P.escheri because there are only a few unreliable findings of that spicies in Serbia, on the south border, and I made this photo in central Serbia .
I would not dare to claim that because neither much more experts, lepidopterologists have found it in Serbia...
I don't know maybe you are right ...
Chapman's Blue(Polyommatus thersites) (26)