Identification: Upper surface of hindwings iridescent blue or blue-green. Underside of hindwing with submarginal row of 7 round orange spots in iridescent blue field. Life history: Adult males patrol likely habitat in search of receptive females. Females lay batches of eggs on underside of host plant leaves. Caterpillars feed gregariously when young but become solitary. Chrysalis overwinters.
Caterpillar host plants: Pipevine (Aristolochia species), including Aristolochia californica, A. serpentaria and others. Pipevines confer a poisonous quality to the larvae and resulting adults, much as the monarch butterfly obtains protection by feeding on milkweed. Adults seek nectar from flowers including thistles (Cirsium species), bergamot, lilac, viper's bugloss, common azaleas, phlox, teasel, azaleas, dame's-rocket, lantana, petunias, verbenas, lupines, star thistle, buckeye and butterfly bush.