Gall inducers, inquilines, and agastoparasites, oh my! Illuminating the evolution of Diastrophini (Cynipidae) through UCE phylogenomics

Ultraconserved elements (UCEs) are highly conserved regions of genomes that distantly related taxa share which can be used to construct phylogenies and elucidate relationships in deep evolutionary time. One group whose understanding has been expanded through UCEs are the gall wasps, inquilines, and parasitoids of the superfamily Cynipoidea. Historically it was thought that gall induction and inquilinism evolved once from a parasitic ancestor, however recent analyses have revealed multiple independent origins of gall induction and have affirmed taxonomic changes favoring monophyletic family and tribal classifications.
While our understanding of the tribal groupings have advanced, there are still many unknowns in regard to the relationships within these lineages, such as the tribe Diastrophini, a group of gall inducing and gall usurping species associated with the plant family Rosaceae. The Diastrophini contains 5 genera: Diastrophus, which induces galls on brambles (Rubus) and cinquefoils (Tribe Potentilleae); Periclistus, which usurps galls of Diplolepis galls on roses (Rosa); Synophromorpha, which usurps galls of Diastrophus; Xestophanes, which induces galls on cinquefoils; Xestophanopsis, whose biology remains unknown. No analyses have included all genera or sampled this tribe extensively, so the intergeneric and interspecific relationships within the lineage are unknown. We sequenced UCEs for Diastrophini to offer the most comprehensive phylogenetic analysis with over 100 sequences focused on the Nearctic and on the species of Diastrophus and their agastoparasites, Synophromorpha.
Our phylogeny reveals transitions between galling and inquilinism, host plants, and gall morphologies; illustrates phylogeographic relationships; and emphasizes the need for further sampling from taxon poor regions.