University of Alberta Museums Search

Closely resembles the spring form of the Mustard White (P. oleracea), but the dark markings along the hindwing underside veins are broad, diffuse, and greyish-green, not well-marked, narrow and dark green as in oleracea. These two species occur together only in the foothills region. Layberry et al. (1998) assign our populations to subspecies marginalis, but Guppy & Shepard (2001) restrict this taxon to the west coast region, and assign Alberta populations to subspecies reicheli. The taxonomy of this difficult group undoubtedly requires further research.

The pale yellow eggs are conical with longitudinal ridges, and mature larvae are an even, unmarked green (Guppy & Shepard 2001). The pupae overwinter, and are dark green to buff-coloured (Guppy & Shepard 2001). The Margined White is single-brooded throughout most of Alberta, possibly double-brooded in the Waterton / West Castle region. This subspecies is double-brooded throughout southern BC (Guppy & Shepard 2001).

Northwestern BC south to California and New Mexico (Opler 1999). In Alberta, this species is restricted to the mountains and foothills, with a disjunct population in the Cypress Hills along the Saskatchewan border (Bird et al. 1995).