Chryxus Arctic (Oeneis chryxus) (Doubleday, 1849)
Diagnosis: The upperside is bright orange brown, with the margins and wing bases slightly darker. There are two to four black eye-spots on the forewing and zero to two on the hindwing near the anal angle; these are repeated below and occasionally have white pupils. The male has a dark greyish sex mark near the forewing costa that sometimes covers the basal half of the wing. The hindwing underside is coarsely striated in dark brown and very pale grey, sometimes with an obscure darker medial band; the veins are usually lined with pale grey. Wingspan: 39 to 54 mm.
Subspecies: There are six recognized subspecies, of which four occur in Canada. The nominate subspecies chryxus flies in the mountains of western Alberta and southern British Columbia; subspecies caryi, from the Boreal Zone of Alberta, British Columbia, Yukon, and the Northwest Territories, has a very contrasting, white-edged medial band on the hindwing underside; subspecies strigulosa, from southern and eastern Ontario and southwestern Quebec, is small and brightly coloured; and subspecies calais, from the rest of Canada, is larger and dull, with the base of the wings dark.
Range: Oeneis chryxus is found from the Gaspé Peninsula, Quebec, to British Columbia, Yukon and the Northwest Territories. It is absent from the Atlantic Provinces, southwestern Ontario, the Prairies, and the west coast. In the west its range extends from Alaska and Yukon south in the mountains to California and New Mexico.
Similar Species: The Great Arctic (O. nevadensis) and Macoun's Arctic (O. macounii). Uhler's Arctic (O. uhleri) and the Alberta Arctic (O. alberta) are dull yellowish or greyish brown above, and uhleri has more hindwing eye-spots. The Sentinel Arctic (O. alpina) has the basal area of the wings much darker, and usually has two hindwing eye-spots, unlike chryxus from northern Canada. [compare images]
Early Stages: The larvae are tan-coloured with reddish hairs. There is a tan dorsal stripe, and brownish and tan lateral stripes separated by white. The head is yellow brown with six brown vertical stripes on top. They have been reared on Poverty Grass (Danthonia spicata) in Ontario and eat other grasses in captivity (Scott, 1986).
Abundance: Common, though usually extremely local.
Flight Season: Oeneis chryxus flies from mid-May to mid-June in eastern Ontario and southern Quebec, from mid-June to mid-July farther north. It flies only in odd years in Manitoba, but every year in the east.
Habits: It is found in dry grassy areas, open pine woods, woodland edges, and arctic and alpine tundra in the west. Subspecies strigulosa is usually restricted to open sandy areas and bare limestone or granite flats, and subspecies calais, at least in northern Quebec, is usually seen in or around bogs.
Remarks: The Chryxus Arctic is a very powerful flier and extremely wary and difficult to approach. When it lands on lichen-covered rocks and leans sideways to minimize its shadow it seems to disappear, only to dash off again as it is approached.
© 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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