The temporal and spatial origins of species remains critical to understanding global biodiversity generation and extinction. Genomic approaches have expanded the tools to understand speciation processes and gene-ecology landscape dynamics. This project will use genomics (e.g. RAD-seq, exon capture) to investigate the formation of host races among endemic legume-feeding psyllids (Arytinnis spp., Psyllidae) in the Canary Islands, a hot spot archipelago with an age progressive series of islands. An island radiation of these insects across the archipelago has resulted in 16 species. Recent and incipient speciation on the youngest islands of La Palma and El Hierro is putatively via host race formation, with divergence in loci involved in specialisation potentially influenced by frequencies in the native host landscape. The student will generate phylogenomic data to look at the spatial and temporal divergence of host races and will conduct field host transplant experiments to explore alternate host tolerance.