Margined White

Not of concern.

Peak flight occurs between mid June to mid July. Possibly a late summer brood in southern mountains.

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).

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.

Meadows and open woodlands of the mountain region.

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).

There are no larval foodplants records for this species in Alberta. In BC, larvae feed on a number of native crucifers (Brassicaeae), including Arabis, Dentaria, and Cardamine (Guppy & Shepard 2001).

Pieris marginalis (margined white) is a butterfly species seen across the coast of Western North America as indicated by data collected by eButterfly.