Format: ORAL

Melissa RL Whitaker

East Tennessee State University, Johnson City TN USA

Cycads support fascinating insect herbivore faunas composed of mutualists like brood site pollinators, as well as parasitic herbivores such as folivorous caterpillars. While most research on cycad-insect interactions has focused on insect pollination, parasitic herbivores also significantly affect the fitness of many cycads, with sometimes dire consequences for cycad conservation and management. These herbivore associations are strongly influenced by cycads defensive traits, particularly their unique chemical defenses, requiring significant adaptation on the part of the insects to be able tolerate, excrete, and/or detoxify cycads phytotoxins. For this reason, the majority of parasitic cycad herbivores are obligate cycad specialists. For example, the neotropical butterfly genus, Eumaeus, is a wholly cycadivorous lineage that feeds primarily on Zamia cycads and provides an emerging model system for investigating cycad-herbivore interactions. Recent research in into Zamia-Eumaeus interactions includes genomic investigations of both the insects and plants, toxicity and survival assays, and chemical analyses. In this presentation, I will synthesize recent research on Zamia-Eumaeus interactions (both published and in progress), including results from preference-performance assays conducted with cycad-specific toxins, and descriptive and experimental investigations into the importance of higher trophic levels driving cycad-insect interactions. I will evaluate these results in the framework of enemy-free space, using a multi-trophic approach to understand the evolution and ecology of cycads fascinating symbioses with insects.