Description
The Northern Blue (Plebejus idas) is a small butterfly with bright blue upper wings in males and brownish-gray in females, and undersides marked with black spots and orange crescents near the edge, typically found in tundra, alpine meadows, and open woodlands across northern North America and Eurasia.
Range
Far northern counties near the Canada border.
Similar Species
Melissa Blue and Karner Blue are similar but neither are found north of Duluth so anything you see up there will be a Northern. You might encounter Greenish Blue in the northeast but that species doesn’t have strong orange markings on the wings below.
Host Plants
Dwarf Bilberry (Vaccinium caespitosum)
Flight
Late-June to Late July