Here's some info on larval foodplants:

"In the suburbs [of Orange County] the larvae are often found on cultivated Hibiscus flowers or leaves. Malva, Humulus (hops), Amorpha (false indigo), Nolina, Polygonum, and Eriogonum are also listed by Emmel and Emmel (1973) and all are conceivably used locally. I reared one larva from Salvia mellifera (Black Sage) in the Arboretum area at U. C. Irvine and this plant may be utilized in our coastal sage-scrub vegetation areas where melinus sometimes occurs. Another native plant which may be utilized locally is California Coffee berry (Rhamnus californica), since a larva has been found recently on this plant at Albany, California. Jack Levy has found a larva on still another locally occurring (but non-native) plant, Cassia alata, in the arboretum area of U. C. Irvine. Thus, plants of many families are utilized."

From Orsak, L. J. (1977). The Butterflies of Orange County, California. Center for Pathobiology Miscellaneous Publication #3. University of California Press, New York. 349pp