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Silvery Blue (Glaucopsyche lygdamus)

Description: A small blue butterfly. The upperside is light metallic blue with a dark grey border on fore and hindwings (this border is broader in females). The underside is grey with a single transverse row of bold white-rimmed black spots on the fore and hindwings. This is the only small blue butterfly with single rows of bold white-rimmed black spots forming a single transverse line on both wings. Wingspan: 18 to 28 mm.

Maritime Distribution: Throughout the Maritimes. For Atlas results click here.

Provincial Ranks: NB: S5 NS: S5. PEI: S5.

Flight Period: Late May to late July.

Host Plant: A variety of legumes (Fabaceae), including Cow Vetch (Vicia cracca), White Sweetclover (Melilotus alba) and Alfalfa (Medicago sativa).

Notes: Silvery Blue is commonly found in a variety of habitats, including forest edges, meadows, and salt marsh edges. It is regularly seen visiting flowers and flying around the host plants, sometimes in large numbers.

Subspecies midredae once existed as a disjunct population in northern Cape Breton but may have been assimilated when subspecies couperi colonized Nova Scotia in the 1960’s. Specimens resembling subspecies mildredae are still seen in coastal areas.