About Glaucopsyche piasus (Boisduval, 1852)
Glaucopsyche piasus, commonly called the silvery blue, has checkered wing fringes. On the upper wing surface, males are violet blue with a wide dark border, while females have a duller coloration. The underside of the wings is gray, marked with many small black spots. On the hindwing, there is a post-median band of white arrowhead-shaped markings that all point inwards. This species has a wingspan ranging from 1 1/8 inches to 1 3/8 inches, which is equal to 2.9 to 3.5 centimeters. During the daytime, males fly and patrol near the species' host plants. Females lay their eggs directly on the flower buds of host plants. This species produces only one brood per year, which flies from March through July. The larvae feed on plant species from two genera: lupines in the genus Lupinus and milkvetches in the genus Astragalus. Adult Glaucopsyche piasus feed on flower nectar.
