New Jersey Butterfly Club

Silvery Blue

Glaucopysche lygdamus

Identification: Very small—about 1". Above: Male FW and HW shiny blue with narrow black margins on both wings; female FW and HW mostly brownish-gray, with blue only toward the base. Below: FW and HW light gray with a single row of prominent, white-ringed black spots on each wing.

NJ Status and Distribution: Vagrant. One record from northern Sussex County (5/28/11).

Habitat: Open areas.

Flight Period: May and June.

Caterpillar Food Plants: Various legumes.

Overwintering Stage: Pupa.

Good Locations: None, but the one location where it has been recorded is the Minisink Preserve.

Comments: The photo of the one individual seen in NJ confirms what one might expect—that it came from the northern population (with smaller black spots) that ranges from southern New York north, rather than from the southern population that ranges from south central Pennsylvania south along the Appalachians. So here we have a northern species that, like Common Ringlet, appears to be extending its range south in the face of a warming climate.