Common Alpine (Erebia epipsodea) (Butler, 1868)
Diagnosis: The upperside of both forewing and hindwing is dark brown with a row of black eye-spots (often white-centred) that are ringed with orange or are in an orange band. The upper two black spots on the forewing are largest and always present. The forewing underside has an orange flush; the outer third of the hindwing underside is light greyish brown, and the upperside spots are repeated. Wingspan: 34 to 45 mm.
Subspecies: There are five subspecies, three of which are found in Canada: the nominate subspecies epipsodea occurs in eastern British Columbia and western Alberta; subspecies freemani, with the orange area around the eye-spots larger, occurs from eastern Alberta to Manitoba, but the two subspecies intergrade in Alberta (Bird et al., 1995); subspecies remingtoni, with reduced eye-spots, occurs in northern British Columbia and Yukon.
Range: Erebia epipsodea flies throughout the northwestern U.S., farther south in the mountains, and from southwestern Manitoba, as far east as Chatfield, to British Columbia, Yukon, and eastern Alaska.
Early Stages: The larvae are light green with a dark dorsal stripe and alternate brown and yellowish lateral stripes, and a yellowish-brown head. They eat grasses and overwinter in the second or third instar, pupating in a nest of grass leaves tied together with silk.
Abundance: The Common Alpine is locally common in western Manitoba, although it is decreasing in abundance owing to destruction of native prairie habitat. In the west it is more widespread and is most abundant in meadows in the aspen parkland and Rocky Mountain foothills (Bird et al., 1995).
Flight Season: Adults are on the wing from early May to October in the prairies and until late August farther north. Males emerge about a week before females.
Habits: In the south epipsodea flies in grassy meadows, moist virgin prairie, marsh edges, and forest clearings. Farther north it is found in mountain meadows and steppe tundra. It has a slow, hopping flight and often visits flowers and mud. However, it has been found to cover large distances, up to 13 km, when dispersing from areas of high population density.
© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.
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