North American Butterflies and Moths List

The definitive website on wildbirds & nature




The Registry of Nature Habitats

U.S. Geological Survey


Butterflies of North America

Arrowhead Blue (Glaucopsyche piasus)
JPG -- species photo

Arrowhead Blue (Glaucopsyche piasus [Boisduval])

Wing span: 1 1/8 - 1 3/8 inches (2.9 - 3.5 cm).

Identification: Checkered fringes. Upperside of male violet blue with a wide border; female duller. Underside gray with many small black spots. Hindwing with postmedian band of white "arrowheads" pointing inward.

Life history: Males patrol during the day near host plants. Females lay eggs on flower buds of host plant; caterpillars eat flowers and fruits. Chrysalids hibernate.

Flight: One brood from March-July.

Caterpillar hosts: Lupine (Lupinus) and milkvetch (Astragalus) species in the pea family (Fabaceae).

Adult food: Flower nectar.

Habitat: Coastal dunes and lowlands in California; mountains elsewhere: scrub, openings in woods, roadsides, trails, meadows, clearings, streamsides.

Range: Local and uncommon. British Columbia and southern Alberta south through the mountains of western North America to southern California, northern Arizona, and western Nebraska.

Conservation: Populations in southern California need assessment; elsewhere populations are probably not in jeopardy.

The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.

Management needs: Not reported.

References:

Scott, J. A. 1986. The butterflies of North America. Stanford  University Press, 
    Stanford, Calif. 583 pages, 64 color plates.

Tilden, J. W. 1986. A field guide to western butterflies.  Houghton-Mifflin Co., 
    Boston, Mass. 370 pages, 23 color plates.

Author: Jane M. Struttmann

Arrowhead Blue (Glaucopsyche piasus)
distribution map
map legend

Disclaimer
Return to species list
Return to Butterflies of North America main page