Species Satyrium calanus - Banded Hairstreak

The subspecies falacer was once considered a separate species

more common in the east than in the west; numbers can fluctuate dramatically from year to year

wingspan 23-34 mm

Adult: underwing gray, submarginal bands narrow, edged white outwardly. Two tails, one short, one medium long. Blue patch not capped with orange, and doesn't extend much beyond orange spots.

Can be quite variable.

Larva: body light green (turns brown just before pupating) with alternating light and dark oblique dashes on the sides

southern Nova Scotia to Florida, west to Texas and Utah, north to Saskatchewan

woodlands, edges, roadsides, open areas near their foodsource and nectar plants

adults fly in April and May in Florida; June to August in the north; most common in July

Larvae feed on leaves of oaks, walnuts, and hickory. In Canada, most common on Butternut (Juglans cinerea). They eat catkins, and then young leaves.

One brood per year; overwinters as an egg.

Around Ottawa, eggs are placed on Butternut so consistently at the base of buds on the previous year's growth that it is not difficult to find them, even during the winter. Egg hatching is synchronized precisely with the opening of the buds to ensure the newly hatched larvae only have to move a few millimetres to reach the new leaflets.

[adapted from text at Butterflies of Canada]