Glaucopsyche lygdamus

"Silvery blue" redirects here. For the other butterfly with this common name, see Lepidochrysops glauca.

Glaucopsyche lygdamus, the silvery blue, is a small butterfly native to North America.

Silvery blue
G. l. couperi, Ottawa, Ontario, Canada
Conservation status
Secure  (NatureServe)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Lycaenidae
Genus:	Glaucopsyche
Species:	G. lygdamus
Binomial name
Glaucopsyche lygdamus (Edward Doubleday, 1841)
Subspecies
See text

Description

Its upperside is a light blue in males and a dull grayish blue in females. The underside is gray with a single row of round spots of differing sizes depending upon the region.

Distribution and habitat

G. lygdamus is found over much of the western United States and most of Canada extending north excepting most of Nunavut and the high Arctic islands. Wingspan is from 18 to 28 mm.^[2][3] It occurs in a variety of habitats including alpine meadows, shale barrens, dunes, and wooded areas.^[4] It feeds on Lupinus plants.^[5]

Taxonomy

The extinct Xerces blue (Glaucopsyche xerces) was once thought to be a subspecies of the silvery blue.

Subspecies

G. l. couperii on tufted vetch (Vicia cracca), Calgary, Alberta, Canada

G. l. palosverdesensis

Listed alphabetically:^[6]

• G. l. afra (W. H. Edwards, 1884) – Afra (silvery) blue
• G. l. arizonensis McDunnough, 1934 – Arizona silvery blue
• G. l. australis (F. Grinnell, 1917) – southern (silvery) blue
• G. l. columbia (Skinner, 1917) – Columbia blue or Skinner's (silvery) blue
• G. l. couperi Grote, 1873 – Couper's silvery blue
• G. l. deserticola (Austin & J. Emmel, 1998) – Mojave silvery blue
• G. l. incognitus Tilden, 1974 – Behr's silvery blue
• G. l. jacki Stallings & Turner, 1947 – Jack's (silvery) blue
• G. l. lygdamus (Edward Doubleday, 1841) – (Georgian) silvery blue
• G. l. mildredae F. Chermock, 1944 – Mildred's silvery blue
• G. l. minipunctum (Austin, 1998) – mini-spotted silvery blue
• G. l. nittanyensis (F. Chermock, 1944) – Appalachian silvery blue
• G. l. oro Scudder, 1876 – oro (silvery) blue
• G. l. palosverdesensis (E. Perkins & J. Emmel, 1977) – Palos Verdes blue
• G. l. pseudoxerces (Emmel & Emmel, 1998) – false Xerces (silvery) blue
• G. l. sabulosa (Emmel, Emmel & Mattoon, 1998) – sand dune silvery blue

Visually similar species

• Eastern tailed-blue (Cupido comyntas) has small 'tails' on hindwings
• Western tailed-blue (Cupido amyntula) has small 'tails' on hindwings
• Arrowhead blue (Glaucopsyche piasus)
• Greenish blue (Aricia saepiolus) has two rows of small black spots on the underside of both wings^[3]
• Boisduval's blue (Aricia icarioides) has two rows of small black spots on the underside of both wings^[3]