The San Bruno elfin's life cycle holds an interesting aspect, common to many other lycaenids regarding a symbiotic interaction with ants.

In exchange for honeydew, the ants often provide protection from harm by predators and parasites, which are principal killers of foliage feeding insects.

Most of these areas, akin to the distribution of the host plant, are scattered on rocky slopes and ledges, especially east facing (McClintock, 1968).

To protect the rare San Bruno elfin as well as the Mission blue butterfly a unique habitat management plan has been implemented on San Bruno Mountain, in which the lower slopes were opened for development while the higher areas were converted to public ownership as critical habitat.

This strategy arose as a compromise result of years of conflict between land developers and conservationists regarding this unique piece of real estate, jointly prized for its outstanding habitat features and its economically valuable location.