Santa Barbara Museum of Natural History

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Santa Barbara Field Guides - Butterflies
Lepidoptera
Lycaenidae
Glaucopsyche piasus
Arrowhead Blue


male upperside	male underside	female upperside	female underside

Size: wingspread .8-1.25 in.
Recognition: Blue with black/white outer wing fringes; female frequently has blue turning to orange/brown near mid-wing and extending to trimming; underside is gray with black spot pattern with white patches in arrowhead-like shapes, hence the name of this Blue.
Flight period: Adults are active from March to July.
Hostplants: A variety of lupine species and sometimes milkvetches are the hostplants for the larvae, specifically Lupinus albifrons and L.excubitus.
Habitat: Chaparral areas with lupines are a favored habitat, as are hillsides, open fields, and mountain clearings.
Distribution: Southwest Canada down through Idaho and into northern Arizona and New Mexico. When found, this butterfly is typically recorded at higher elevations from San Bernardino mountains, north into Kern and Ventura counties, including the Sierras. This is a rather obscure butterfly, and if present in Santa Barbara County it would be found in the backcountry.
Other: The subspecies, G.piasus sagittigera is noted to have previously been very common in the lowlands of Los Angeles County, but the gradual disappearance of habitat due to urban developments is decimating the colonies there, and it is now possibly extinct.

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