About Erebia discoidalis Kirby, 1837
Erebia discoidalis, commonly known as the red-disked alpine, is a butterfly species belonging to the subfamily Satyrinae of the family Nymphalidae. Its range spans North America from eastern Quebec, through northern Ontario (reaching south to Sudbury), and the northern Prairies, extending west to northern British Columbia, the Northwest Territories, Yukon, and Alaska. It also extends just into the northern United States between Michigan and Montana. Additionally, it occurs in Asia, where it has been recorded from the Chukot Peninsula to the eastern Sayan Mountains and Amur. Its preferred habitat includes large open grassy bogs and other areas with acidic soils. The wingspan of this species measures 35–44 mm. As described in Seitz: E. discoidalis Krb. (= lena Christ.) (37 h). The forewing is narrow, with a rounded apex. The costal margin is brownish grey, striped with whitish grey and brown. The dull brown disc has a broad dark chocolate border along its anterior and posterior edges; this border is narrow on the distal side, and the dark apex of the wing is lightly dusted with grey. The underside of the forewing matches the pattern of the upper side, though the border of the brown central area is somewhat broader, and the apex and distal margin are densely dusted with bluish grey. The underside of the hindwing is dark brown from its base to the middle, thinly dusted with whitish grey. The outer half is blue-grey marked with small dark brown stripes. An oval whitish grey spot sits at the apex of the cell, and 2 to 3 smaller similar spots are present on the costal margin. This description notes the species occurs in Central and Eastern Siberia (Amurland), as well as Arctic America. Graeser found the species to be very rare at Podrofka in June; based on the worn condition of the specimens he collected, he concluded the insect may be more abundant earlier in the year. Adult red-disked alpines are on wing from May to late July, depending on their location. The larvae feed on plants of the Eriophorum species.
