My research concerns systematics of gall wasps, combining molecular, morphological, and collections-based approaches to understand their evolution and diversity. Gall wasps comprise a diverse lineage that induce galls—growths developed by host plants to shelter and feed the wasp’s offspring. I recently led the largest phylogenetic study of gall wasps to date, using next-generation sequencing to establish a robust evolutionary history of gall induction for over 350 taxa. I also published the first study to demonstrate the utility of DNA barcoding in herb gall wasp species delimitation. Through taxonomic studies, I developed identification keys, catalogs, and comprehensive revisionary monographs for several gall wasp groups, including descriptions of over 60 species and genera new to science. Over the course of these studies, I have conducted research and curation visits to multiple major insect collections across the United States. Species included in these studies are biocontrol agents, emerging pests, new introductions, and species of conservation interest, highlighting the value of taxonomy to applied areas. Altogether, these studies have produced taxonomic stability for several important taxa, established a robust evolutionary framework for the Cynipoidea, and unlocked the previously unknown biodiversity of these fascinating insects. New and ongoing projects include taxonomic and evolutionary studies for herb and inquiline gall wasps, as well as gall wasp parasitoids in the superfamily Chalcidoidea.