Arctic Fritillary (Boloria chariclea) (Schneider, 1794)
Diagnosis: This species varies considerably in its widespread range, but generally falls into tundra forms and taiga (boreal forest) forms. Above, it is dark orange with black spots, bars, and chevron-shaped markings. The hindwing underside of the taiga forms (subspecies grandis and rainieri) is purplish or red brown with a broken yellowish to rust-coloured band across the wing; it has white marginal spots capped with black chevron-shaped marks and a row of black spots above these. The two tundra subspecies (subspecies arctica and butleri) have a distinct white band (sometimes silvered) across the middle of the hindwing underside and the black submarginal spots and chevron marks are reduced or absent. Wingspan: 32 to 44 mm.
Subspecies: Subspecies chariclea is in the Old World. Subspecies arctica is the most northerly subspecies, occurring in tundra habitat from Greenland south to Newfoundland and across arctic Canada to Yukon, where it is replaced by subspecies butleri in parts of Yukon and Alaska. Subspecies grandis occurs in the Boreal Zone across Canada from Labrador to Yukon and British Columbia, intergrading in the northern part of its range with subspecies arctica. The more brightly coloured subspecies rainieri is found in southern British Columbia.
Range: This circumpolar fritillary is found in Canada from northern Ellesmere Island to the U.S. border. It is widespread in all provinces and territories, except Prince Edward Island, southern Ontario and Quebec, the prairie region, and coastal British Columbia.
Early Stages: The grey larva has black stripes and orange spines. It feeds on Western Bistort (Polygonum bistortoides), willows (Salix spp.), and possibly violets. In the colder parts of its range, it takes two years to develop (Acorn, 1993), but can be found every year in most areas.
Abundance: In the Arctic, the western mountains, and in some bogs, it is the most abundant lesser fritillary.
Flight Season: Boloria chariclea is on the wing from June into August depending on the altitude andlatitude.
Habits: The Arctic Fritillary has a wide preference for habitat depending on location. In the west and north it flies in cool, moist meadows. In the more easterly and southerly parts of its range it is found in boreal woodlands and bogs.
Remarks: Until recently, two species were recognized in North America: Boloria titania (Esper, [1793), a Boreal Zone species of Europe and North America, and Boloria chariclea, a circumpolar tundra species. Boloria titania is now considered to be restricted to Europe and all North American populations are combined under B. chariclea. There is still debate as to whether the Boreal Zone populations in North America (formerly Boloria titania but now treated as a subspecies of Boloriachariclea) should be treated as a separate species from the tundra populations. In some areas, forexample some parts of Yukon and Alaska, the tundra form of Boloria chariclea (subspecies butleri) flies in alpine meadows with the taiga form (subspecies grandis) occurring in the boreal forest of nearby valleys with no evidence of hybridization. In central Alaska the tundra form is strictly biennial, but the taiga form flies every year. In other areas of northern Canada the two habitat forms intergrade completely. This appears to be an example of what is termed "a circle of races," where two subspecies (tundra subspecies butleri and taiga subspecies grandis) occur together without interbreeding but both interbreed freely with a third subspecies (arctica). We treat the tundra and taiga forms as subspecies of Boloria chariclea, while recognizing that in some areas they behave as distinct species.
© 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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