Formerly common in the Central Valley, Delta, Bay Area and lower foothills, this species has suffered an unexplained crash and is teetering on the brink of regional extinction. It had been a great success story! From its biology we inferred that its native host plant was the tall mustard Guillenia (formerly Thelypodium) lasiophylla, now a rare plant in the Valley grasslands. It had successfully made the transition to naturalized annual species of Brassica and Raphanus and was doing very well through the 1980s.

See discussion of the three entities in this complex under E. hyantis hyantis

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Three different subspecies (two of them named) occur on our transect.

Confined to sagebrush-bitterbrush shrub-steppe on the Sierran East slope. See discussion under E. hyantis hyantis, where the three entities along the transect are compared.