In recent years, new wasp species and genera of Cynipidae have been described, and their species delimitation and evolutionary relationships have been supported using molecular markers. However, few studies have included comprehensive and extensive sampling of specimens across the complete distribution of a single genus. In this study, we analysed the phylogenetic relationships of the genus Amphibolips throughout its range using ultraconserved elements (UCEs). We collected 520 adult wasps from 401 sites in various geographic locations, predominantly in Mexico, and used 78 wasps for UCE analysis. Our results demonstrate that Amphibolips forms a monophyletic clade. Amphibolips can be further subdivided into four genetically well‐differentiated clades. Each clade had morphological traits that could be collectively characterised. Species delimitation using molecular sequencing highlights the taxonomic complexity involved in separating and assigning species using exclusively morphological criteria. This approach offers an opportunity to refine current morphological taxonomic criteria or propose new criteria to establish more accurate classifications. The rich diversity of host species and geographic regions in Mexico represents a biodiversity hotspot for Amphibolips. The number of undescribed species remains high. This study facilitates the determination of appropriate boundaries for putative new Amphibolips species.