CALIFORNIA ACADEMY OF SCIENCES
Hotspot: California on the Edge
Mission Blue Butterfly
Mission Blue Butterfly
Icaricia icarioides missionensis

Once widespread on the San Francisco peninsula and Marin, the mission blue butterfly is now restricted to just a few coastal sage scrub sites where its host plants still exist.
Adults feed on the nectar of several plants including buckwheat, golden aster and wild hyacinth, but do not wander far from lupine on which females will lay their eggs. When the eggs hatch the young larvae begin feeding on lupine leaves and flowers. After feeding, the caterpillars drop to the base of the plant where they enter a dormant stage and pupate in the soil.

The male’s upper wing surfaces are iridescent blue and lavender with black margins fringed with long white scales. Females have dark brown upper wing surfaces marked with blue basal areas. Mission blue butterfly caterpillars are tended like cattle and protected by ants because they secrete sweet honeydew which the ants feed on.

Habitat Loss
Much of the remaining habitat of the mission blue butterfly occurs on private lands in San Mateo County that are planned for housing developments. 

Conservation & Protection
Preservation of existing butterfly populations relies on replanting host plants, removing introduced plants, and protecting the land from development or excessive recreational use. A habitat conservation plan was developed for the rare butterflies on San Bruno Mountain where 2,000 acres of critical butterfly habitat are managed by the San Mateo County Department of Parks and Recreation.

Plant native gardens that include host plants for mission blue butterflies. Volunteer to remove invasive plant species in open space lands and parks: Golden Gate National Parks Conservancy www.parksconservancy.org.

 

Above: Mission Blue Butterfly

Mission Blue Butterfly

Threats

Habitat Loss

Conservation & Protection

What You Can Do