Wikipedia
Arethusana
Arethusana is a butterfly genus from the subfamily Satyrinae of the brush-footed butterfly family (Nymphalidae). It is composed of only one species, Arethusana arethusa, the false grayling, which can be found as far west as Morocco and as far eastward as SW. Siberia and N. Tian Shan.
The wingspan is 44–48 mm and the length of the forewings is 21–25 mm. Adults are on wing from July to September.
The larvae feed on various grasses, including Festuca, Bromus erectus, Dactylis and Poa species.