Erebia medusa (Denis & Schiffermüller, 1775)


Erebia medusa: Male (eastern Swabian Alb, Southern Germany) [N] Erebia medusa: Male (eastern Swabian Alb, Southern Germany) Erebia medusa: Male (eastern Swabian Alb, Southern Germany) Erebia medusa: Adult (eastern Swabian Alb, Southern Germany) [N] Erebia medusa: Female (eastern Swabian Alb, Southern Germany) [N] Erebia medusa: Female (eastern Swabian Alb, Southern Germany) [N] Erebia medusa: Adult Erebia medusa: Adult (eastern Swabian Alb, Southern Germany, late May 2012) [N] Erebia medusa: Adult (eastern Swabian Alb, Southern Germany, late May 2012) [N] Erebia medusa: Female (e.l. eastern Swabian Alb) [S] Erebia medusa: Female [N] Erebia medusa: Lower side [N] Erebia medusa: Mating [N] Erebia medusa: Ovum, freshly deposited [S] Erebia medusa: Ovum [S] Erebia medusa: Ovum after some days [S] Erebia medusa: L1-larva [S] Erebia medusa: Young larva [S] Erebia medusa: Half-grown larva [S] Erebia medusa: Hibernating larva (09/02/2008), Swabian Alb, Southern Germany [M] Erebia medusa: Larva after the last moult  [S] Erebia medusa: Larva (brownish form, eastern Swabian Alb, e.l. Southern Germany) [S] Erebia medusa: Larva (brown form, eastern Swabian Alb, Southern Germany) [M] Erebia medusa: Larva (green, e.l. eastern Swabian Alb) [S] Erebia medusa: Larva (eastern Swabian Alb, Southern Germany) [M] Erebia medusa: Pupa ventral [S] Erebia medusa: Pupa [S] Erebia medusa: Pupa dorsal [S] Erebia medusa: Pupa [S] Erebia medusa: Pupa [S] Erebia medusa: Pupa (prior to emergence) [S] Erebia medusa: Pupa prior to emergence (e.l. eastern Swabian Alb) [S] Erebia medusa: Habitat: more mesophilic nutrient-poor meadow with relative dense vegetation [N]

Host plants:
The larva feeds on grasses (Poaceae, rarely also Cyperaceae). I found caterpillars especially on Festuca ovina agg., Bromus erectus (grasslands of the eastern Swabian Alb) and once on Phalaris arundinacea (Iller valley in Southern Germany).

Habitat:
Erebia medusa inhabits nutrient-poor grasslands, extensive meadows, fens, marshes, forest meadows and clear-cuttings. The butterfly prefers slightly higher and denser growing grasslands, but does not require necessarily a woody component. On the other hand, I also observed larvae together with those of Apamea furva in isolated Festuca tufts on rocks.

Life cycle:
The adult flies in one generation between May and June. At higher elevations, it is still flying in July (e.g. Olympus, Northern Greece, 2500m above sea level, in late July 2010) The caterpillar overwinters as L4 and is mature in April or early May. I found overwintering caterpillars repeatedly in the base of tufts of Festuca ovina agg. (eastern Swabian Alb) between November and March.

Endangerment: regionally endangered or decreasing

Endangerment factors:
Overall, Erebia medusa is still well represented in Central Europe, especially in Southern Germany, but more rarely in the north. It is in decline outside of the larger nutrient-poor grassland regions because of eutrophication, intensification, overbuilding and afforestation.

Remarks:
The distribution ranges from central and Eastern Europe to China. In the Alps Erebia medusa is found in the north only in the valleys, while it is represented in the south up to more than 2000m above sea level. The reason is probably the dense occurrence of the sister species Erebia oeme in the northern Alps.
To the southeast Erebia medusa reaches Central Greece (e.g. on Mount Olympus up to 2600m above sea level and in the Pindos range).



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