Studies on the diversity, host plant use, and evolutionary patterns of the flea beetle genus Epitrix Foudras (Coleoptera: Chrysomelidae: Galerucinae: Alticini) were performed with emphasis on species in America north of Mexico. Epitrix was revised for America north of Mexico with 13 new species described. Distributional records of species from museum specimens were used to construct niche models to predict the full distributions of the species and where the species may potentially become invasive globally. A population level genetic analysis was performed on the eggplant flea beetle Epitrix fuscula Crotch in eastern North America looking at population dynamics between populations on different hosts across its range. A higher phylogeny of Epitrix species was constructed using two mitochondrial and two nuclear genes with focus on the species north of Mexico, and evolutionary patterns of host use were explored with respect to host phylogeny. Host use patterns were found to be phylogenetically inconsistent with host phylogeny, and genetic diversity between populations of E. fuscula was explained by geography rather than host plant. This research suggests that host plant shifting between plant clades may be common in Epitrix. Additional research is needed to establish the age of Epitrix to determine when it first adapted onto Solanaceae.
