Mission Blue Butterfly
NPS Photo
Scientific Name: Icaricia icarioides missionenses
Family: Lycaenidae (Gossamer-winged butterflies)
Size: Adults are about the size of a quarter (0.08 to 0.13 inches). Larvae are very small and rarely seen.
Description: On the upperside of the wings, the adult female is brown with some blue, and the male is light blue. Both have blackish wing edges. The underside of the wings is off-white with two rows of irregularly shaped black spots. The larva (caterpillar) is light green with diagonal white bars on each segment.
Diet: Mission blue larvae will feed only on the leaves of the three host lupines in their habitat (L. albifrons, L. formosus, and L. variicolor). The host lupines are plant species that provide subsistence (food and shelter) to the butterfly. Adults may drink the nectar of composite flowers (sunflower family) using a long tube called a proboscis that extend from the underside of the head.
Habitat: The Mission blue requires a host plant and appropriate nectar plants in a coastal grassland habitat. The host plants utilized by the Mission blue are silver lupine, summer lupine, and varicolor lupine. Nectar plants include various composites that grow in association with the lupines. In GGNRA, the Mission blue has been viewed at Milagra Ridge and in the Marin Headlands.
Status: Federally Endangered. Remaining populations of the Mission blue are found in only a few locations around the San Francisco Bay Area in California including the Marin Headlands, the coastal ridges in San Mateo County, San Bruno Mountain, and possibly Twin Peaks in San Francisco.
Interesting Information: The historical distribution probably encompassed much of the coastal scrub/grassland habitat of the northern San Francisco peninsula and Marin County.
References:
Arnold, Richard A. 1983. Ecological Studies of Six Endangered Butterflies (lepidoptera, Lycaenidae): Island Biogeography, Patch Dynamics, and the Design of Habitat Preserves. UC Publication in Entomology, Volume 99. UC Press.
Cushman, J. Hall. 1993. The Mission Blue, Plebejus icariodides misionensis Hovanitz. In Conservation Biology of Lycaenidae (Butterflies), ed. T.R. New International Union for Conservation of Nature and Natural Resources, Gland, Switzerland.
