Erebia nivalis Lorkovic & Lesse, 1954

Host plants:
The caterpillars feed preferred on tufty grasses, most often on Festuca species

Habitat:
Erebia nivalis inhabits alpine, only gappy overgrown slopes that are often (but not necessarily) interspersed with rocks and stones between 2200m and 2600m asl. I found the butterfly on the Grossglockner High Alpine Road (Austria) between 2300m and 2500m above sea level in a very nutrient-poor and sparsely vegetated terrain, which was riddled with higher growing depressions and showed a remarkable species community: among others Setina irrorella, Setina roscida, Erebia gorge, Erebia pandrose, Polyommatus orbitulus, Boloria napaea, Zygaena exulans, Pyrgus andromedae, Pyrgus cacaliae, Pyrgus warrenensis, Melitaea asteria.

In the few localities in Switzerland (Faulhorn, Schilthorn) Erebia nivalis seems to populate particularly steep ridges and rock bands (Sonderegger 2005).

Life cycle:
The development is biennial. The first winter is usually passed in the the first instar, then the second in penultimate. The adults fly hence earlier than Erebia cassioides and E. tyndarus, namely from late June to mid or late August. I met the butterflies in late July (only fresh male) and mid-August 2009 (fresh females, males moderately worn) on the Grossglockner High Alpine Road. Somewhat lower (at 2100m above sea level) and just a few kilometers further I found fresh adults of Erebia cassioides in mid-Augus but neither E. nivalis nor Setina roscida.

Endangerment factors:
Erebia nivalis is threatened only slightly in many sites thanks to the altitude. But it can be locally affected or even disappear by the far too intensive tourism and the therefore necessary infrastructure (Alpine roads, slopes, lifts, etc.).

Remarks:
Erebia nivalis is found mainly in the eastern Alps in Austria, east of the Ötztal, particularly widespread for example in the Hohe Tauern. In addition, it is found extremely local also in the northeastern Italian Alps and the Berner Oberland in Switzerland.

Hints on determination:
Erebia nivalis is difficult to distinguish from similar species of the Erebia tyndarus group. Fresh males have a bluish touch on hind wing underside. On forewing upperside two of the reddish brown flecks reach the cel, but this can rarely occur also with other species. The two eye spots are not coherent what stands in contrast to females of E. cassioides. But E. cassioides males often also show separated eye spots (eastern Alps).

The head horns of the older caterpillars are much shorter than those of E. cassioides and E. tyndarus.