The selection of local host plant for generalized insect herbivores is a complex process that involves biochemical plant defenses, insect behavior, insect detoxification, and evolutionary "constraints" related to recent and past ecological factors which have resulted in differential mortality on different plant species (and hence natural selection for use of specific hosts). The PIs have proposed a new hypothesis to help explain local feeding specialization where numerous host choices are available. This concept (called the voltinism-suitability hypothesis) integrates abiotic and biotic environmental influences in order to predict host selection in the face of multiple options for plant- feeding insects. Species of Papilio butterflies are a model system to explore ecological processes of predation, parasitism, and competition as factors affecting host choice. This research will assess the relative significance of these selective pressures compared to the seasonal thermal unit restrictions and insect evolutionary history as determinants of specific feeding choice in generalized insects. Such information may improve the predictive capabilities in regard to host shifts, and the evolution of insect populations that are resistant to natural plant defensive chemicals and synthetic pesticides.
