The signature riparian butterfly of our region, occurring along streams in foothill canyons and on the Central Valley floor, essentially everywhere where its only host plant, California Pipevine or Dutchman's Pipe, Aristolochia californica, occurs. (It also occurs in coastal scrub vegetation, where there are no transect sites.) It is unmistakeable and very conspicuous as both a larva and an adult. Only the pupa is cryptic (either brown or green, with a delicate golden filigree).