Pyrgus warrenensis - Warrens Skipper 

Pyrgus-warrenensis-warrens-skipper- | PTKbutterflies

This very small skipper butterfly has been the most difficult of all for me to identify, but I am currently content this is warrenensis. It flys in the high Alps, this one being photographed in the Stelvio Pass region of Italy. It seems most difficult to separate from a small individual of cacaliae or alveus, but this one was really small, with a narrow forewing