Trophic specialization and genetic structure in phytophagous insects

Abstract

Ecological specialization is a key promoter of speciation. Specialization influences genetic diversity, and hence contributes to the organization and differentiation of terrestrial communities. The investigation of how the ecological specialization of phytophagous insects shape their genetic diversity within and among host plants along their geographic range contributes to elucidate one of the mechanisms that originated more than half of global diversity. The aim of this project is to investigate the structure of the genetic diversity of endophagous herbivores of the pan-American genus Tomoplagia (Diptera: Tephritidae), that vary in degree of specialization in its Asteraceae host plants and in geographic range. We expect to observe higher genetic diversity in herbivores feeding on higher taxonomic and phylogenetic diversity of plants, and with larger geographic range. Furthermore, relative partition of genetic diversity among hosts and among locations may indicate changes in the source of genetic diversity for herbivores that vary in degree of specialization. Ultimately, we expect to observe genetic differences in generalist herbivores feeding on different hosts in the same location evidencing the formation of host races.