Mustard White (Pieris oleracea)
Description: Besides Cabbage White, this is the only nearly all white butterfly in the Maritimes. It is distinguished from Cabbage White by the absence of distinct black spots on the forewing. There are two forms of this species, one occurring in spring with dark pigmentation along the veins, particularly on the underside of the hindwing, and a second occurring in summer that lacks this dark pigmentation. Wingspan: 32 to 50 mm.
Maritime Distribution: Throughout Maritimes. For Atlas results click here.
Provincial Ranks: NB: S5. NS: S4. PEI: S4.
Flight Period: Double brooded, early May to mid June, mid July to late August.
Host Plant: A variety of species in the mustard family (Brassicaceae), particularly rock cresses (Arabis spp.) and toothworts (Cardamine spp.).
Notes: Mustard White is typically found along roadsides and in open spaces in forested areas.