Synonyms and other taxonomic changes
Adelpha bredowii subspecies californica
Limenitis bredowii subspecies californica
Explanation of Names
There are 3 closely related populations of Sisters that have until recently been treated as subspecies of one species - Adelpha bredowii. Most now consider these to represent three distinct species, though the question is still debated:
Adelpha bredowii (not north of Mexico; sometimes spelled bredowi)
Adelpha californica
Adelpha eulalia
Identification
Lorquin's Admiral - Limenitis lorquini is very similar, differing in its smaller average size and in the arrangement of the markings. The white band is more curved on the hind wing; there is an orange band outside the white band below on HW; there are no silvery/bluish parallel stripes near the base below on HW. On the upper front wing Lorquin's Admiral usually has a white bar near the front margin, while the California Sister has two red/orange bars there. Lorquin's Admiral is usually associated with shrubs or trees of the Willow or perhaps Rose Families, often in riparian areas, while California Sister is usually associated with Oak Woodlands; however, the two may often be found in the same areas. Lorquin's Admiral is usually single-brooded, most abundant in early summer.
Arizona Sister - Adelpha eulalia is very similar, but occurs further east (probably rarely if ever in the same areas), and differs in details of pattern, particularly in the stripes near the base of the under side of the hind wings.
Range
Far western North American; from west edge of interior deserts to Pacific coast in Baja California, California, Oregon, barely into westernmost Nevada, and occasionally into Washington (probably as a stray).
Habitat
Mostly mountain and canyon terrain. Associated with Oaks (Quercus species, which are the larval food plants.
Season
Adults fly in two or three (perhaps more in south) broods from spring to frost, mostly April to September.
Internet References
The two sisters - an illustration of the differences between the California and Arizona Sisters