Santa Barbara Museum of Natural History

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Santa Barbara Field Guides - Butterflies
Lepidoptera
Lycaenidae
Glaucopsyche lygdamus
Silvery Blue


male upperside	male underside	female upperside	female underside

Size: wingspread .8-1.25 in.
Recognition: Male is bright silver-blue; female is dark brown and with faint blue near body; both sexes have outer black trimming down wings and white fringes; underside is grayish with row of black-centered white spots down wings.
Flight period: Adults are active from mid-spring to early summer in our area.
Hostplants: Larvae are known to specifically feed on Lotus scoparius, but other Lotus species, lupines, vetches, and milk vetches are used also.
Habitat: They prefer open areas in montane settings, such as fields, hillsides, meadows, and clearings. They are often found around foodplants.
Distribution: Occurs throughout much of the western U.S., north into Canada and Alaska.
Other: The Xerces Blue was a subspecies of the Silvery Blue, but it is now extinct due to loss of sand dune habitat in the San Francisco area. The Xerces Society, an organization dedicated to invertebrate conservation, is named after the tragic loss of this butterfly.

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