Foodplant preferences of Pieris caterpillars (Lepidoptera).

Larvae of five Nearctic Pieris butterflies accept a wide range of native and naturalized crucifers under laboratory test conditions. Preferences among crucifers are usually statistical rather than absolute. Caterpillars do not necessarily reject plants that do not support larval growth in favor of those that do. Preferences are not significantly altered by larval development or prior experience with specific foodplant species. Progeny of different females do not exhibit significantly different preferences. Retention of behavioral flexibility by Pieris may enable older larvae to exploit alternative resources not suitable for young larvae.