Erebia styx (Freyer, 1834)

Host plants:
The larvae feed on Sesleria varia and certainly other grasses. In the Bavarian Alps they probably use mainly Carex mucronata, which was the most common and in some egg observation sites the only grass.

Habitat:
Erebia styx occurs only on larger rocks or stony and rocky slopes from about 700m above sea level to the tree line.

Life cycle:
In the Bavarian Alps the life cycle presumably takes a single year. The caterpillar overwinters in the first instar and eats only slightly in the autumn. Mature caterpillars could probably be mainly observed in late June/early July. The adults fly from late July to early September. In mid-August 2006 many butterflies have been observed at around 900 meters above sea level, also some eggs on Carex mucronata and nother plants, always close to the ground on plant patches directly on rocks (together with Ulrich Rau and Mario Peluso).

Endangerment factors:
In some places, Erebia styx is endangered through succession and reforestation in lower sites.

Remarks:
Erebia styx is mainly distributed in the eastern Alps, west to the Ticino and the Bavarian Alps.