|scientific name Polygonia oreas |
common name Oreas Comma
Moist forest habitats at low elevations in the Waterton - Crowsnest region.
One brood per year, appearing in early spring (April to May) and again in August to October.
This is one of three commas with a dark, two-toned underside; distinguished from the Hoary Comma (P. gracilis) by the dark brown rather than grey underside and more prominent patches of white wing fringes. The underside of the Grey Comma (P. progne) is very similar, but the upper surface of Oreas is darker overall with larger black patches, giving it a much blotchier appearance than progne.
Southeastern BC and Alberta populations are lighter in colour and have smaller dark dorsal spots than coastal Oreas, and have recently been named as subspecies threatfuli by Guppy & Shepard (2001).
Some authors consider Oreas as a subspecies of the Grey (eg. Opler 1999, Scott 1986). Both forms, however, occur together in parts of Alberta and British Columbia without apparent interbreeding (Bird et al. 1995, Guppy & Shepard 2001).
The larva is dark brown, with a yellow-orange dorsum near the front, and pale yellow near the back; it has rows of branched spines and black V-marks along the dorsum. The pupa is mottled brown (Scott 1986). Adults appear early in the spring after hibernating to mate and reproduce. This species is generally rare and locally distributed (Guppy & Shepard 2001).
Less than ten locations known for Alberta; of special concern (S3) in BC.
Like the Grey Comma, the larvae of this species feed on currants and gooseberries (Ribes spp.) in the Pacific Northwest, and presumably do so in Alberta. There are several species of Ribes found in the Waterton - Crowsnest region where Oreas flies (Moss 1992), but the species known to be a host in coastal BC, R. divaricatum (Guppy & Shepard 2001), does not occur here.
A species of western North America, ranging from southern BC and extreme southwestern Alberta south to California and Colorado (Opler 1999).
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