Phasing in and out of phytophagy: phylogeny and evolution of the family Eurytomidae (Hymenoptera: Chalcidoidea) based on Ultraconserved Elements

We present the first global molecular phylogenetic hypothesis for the family Eurytomidae, a group of chalcidoid wasps with diverse biology, with a representative sampling (197 ingroups and 11 outgroups) that covers all described subfamilies, and 70% of the known genera. Analyses of 962 Ultra-Conserved Elements (UCEs) with concatenation (IQ-TREE) and multispecies coalescent approaches (ASTRAL) resulted in highly supported topologies in recovering the monophyly of Eurytomidae and its four subfamilies. The taxonomy of Eurytomidae, and in particular the large subfamily Eurytominae, needs major revisions as most large genera are recovered as para- or polyphyletic, and the erection of multiple new genera is required in the future to accommodate these taxa. Here, we synonymize the genera Cathilaria (C. certa, C. globiventris, C. opuntiae, and C. rigidae) and the monotypic Aiolomorphus rhopaloides within Tetramesa syn. nov., Parabruchophagus (P. kazakhstanicus, P. nikolskaji, P. rasnitsyni, P. saxatilis, and P. tauricus) and Exeurytoma (E. anatolica, E. caraganae, and E. kebanensis) within Bruchophagus syn. nov.. We also provide 137 DNA barcode COI fragments extracted from the UCE contigs to aid in future identifications of Eurytomidae using this popular genetic marker. Eurytomidae most likely originated in South America with an estimated crown age of 83.37 Ma. Ancestral state reconstruction indicates that secondary phytophagy has evolved at least seven times within the subfamily Eurytominae, showcasing the evolutionary flexibility of these vastly understudied wasps.