Silvery Blue Glaucopsyche lygdamus (Doubleday, 1841)

hide

Family: Lycaenidae

Subfamily: Polyommatinae

Identification: Upperside of male iridescent silvery blue with narrow dark borders; female darker blue with wide borders. Both sexes have white fringe. Underside gray-brown; both wings with row of white-ringed, round black spots. Subspecies xerces (Boisduval) and pseudoxerces Emmel and Emmel have large white spots with or without black centers.

Wing Span: 7/8 - 1 1/4 inches (2.2 - 3.2 cm).

Life History: Males patrol near the host plants for females. Eggs are laid singly on flower buds and young leaves of the host plants. Caterpillars feed on flowers, seedpods, and young leaves and are tended by ants. Chrysalids hibernate.

Flight: One flight from March-June at low elevations, June-August at high elevations.

Caterpillar Hosts: Astragalus, Lotus, Lupinus, Melilotus, Oxytropis, Lathyrus, Vicia, and other species in the pea family.

Adult Food: Nectar from flowers including Asteraceae.

Habitat: A variety of locations including open woods, coastal dunes, prairies, meadows, road edges, rocky moist woods, and brushy fields.

Range: Central Alaska south to southern California, Baja California, Arizona, New Mexico, and western Kansas. Along northern United States east to Nova Scotia and south to Georgia.

Conservation: Subspecies palosverdesensis is thought to be extinct. Its historic range and its hostplant Astragalus leucopsis in the Palos Verdes Hills in Los Angeles County, California is largely extirpated, but an additional population was discovered in nearby San Pedro. This subspecies has The Nature Conservancy rank of T1 - Critically imperiled globally because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout its range). Subspecies xerces is TX - Presumed extinct. Subspecies pseudoxerces is rank T2.

NCGR:

Management Needs: Conserve all remaining habitat for the Palos Verdes Blue. Investigate status and conservation needs of subspecies pseudoxerces.

BAMONA Shop

New April 2025 Earth Day Special Release Shirts!

Please donate!

We depend on donations to keep Butterflies and Moths of North America freely available. We want to express our gratitude to all who showed their support by making a contribution this year. You can donate to support this project at any time.

Advertise with us!

Do you have a product or service that you think would interest BAMONA users? If you would like to advertise on this website, contact us by email, or use the contact form and select the "Advertising" category.

Detailed record
Historical record

Leaflet | Map data © Google,

Verified Sightings

Displaying 1 - 24 of 2800 verified sightings

Filter by Region

Observation date: Apr 22, 2025

Submitted by: MAKI

Region: Santa Barbara County, California, United States

Verified by: Ken Davenport

Verified date: Apr 27, 2025

Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

Please donate!

Advertise with us!

Verified Sightings

Advertisement

Silvery Blue
Glaucopsyche lygdamus (Doubleday, 1841)