Phylogenetic Patterns of Diversity in Herbivorous Insects

Abstract

Herbivorous insects comprise an extraordinary amount of the world’s biodiversity, but we do not fully understand what led to the extensive diversification within this group. Popular hypotheses focus on coevolutionary dynamics between herbivorous insects and their host plant, but their predictions have not been rigorously tested. I approach this problem in two ways. First, I test a set of UCE (Ultraconserved Elements) probes for their suitability to estimate a better aphid phylogeny, finding that these probes capture enough genomic data to potentially resolve areas of uncertainty in the aphid phylogeny. This is a crucial step for testing hypotheses of diversification and speciation in this group. Next, I perform novel comparative phylogenetics in nymphalids to test the prediction that host switches in herbivorous insects are linked to increased speciation, finding instead that host switches are associated with a decrease in speciation in nymphalids. This suggests that we need to reconsider our assumptions and hypotheses about diversification in herbivorous insects.