While Polyphylla larvae are generally considered to be grass and pine root feeders (Andrews, California Department of Food and Agriculture, pers. comm. 1993; Evans, Los Angeles Museum of Natural History, pers. comm. 1993), the Mount Hermon June beetle may also feed on the roots of monkeyflower, oak, fern and other plants found in the Zayante sand hills ecosystem (Hazeltine, in litt. 1993).