Abstract This study evaluates the phylogenetic validity of traditionally defined species groups within the genus Eurytoma Illiger in the Palaearctic region using mitochondrial genome data, with a focus on genus‐ and species‐group–level relationships. A total of 166 specimens were analysed, comprising 159 ingroup specimens and seven outgroups, covering 13 of the 18 historically recognized species groups. Ten groups were recovered within Eurytoma sensu stricto ( s.s. ), whereas several traditionally recognized species groups were polyphyletic or placed outside Eurytoma , thereby refining the generic limits of the genus. Notably, morphological traits used in species‐group diagnosis, including the postgenal depression and ventral shelf structure, corresponded closely with the molecular phylogeny, whereas classifications based primarily on ecological similarity or putatively adaptive traits were not consistently supported. Ancestral state reconstruction revealed that entomophagy was ancestral across Eurytomidae, with a single transition to phytophagy inferred within Eurytoma s.s. , corresponding to the fumipennis and amygdali groups. Multistate analyses further identified recurrent transitions among gall‐associated parasitism, seed‐feeding and coleopteran parasitism, including at least two independent origins of coleopteran parasitism within Eurytoma s.s. These results indicate that host‐use is phylogenetically labile in Eurytoma and that convergent ecological strategies have evolved repeatedly across the genus. This study provides the first mitogenome‐based phylogenetic test of historical species‐group coherence in Eurytoma at the genus‐ and species‐group levels. The revised framework clarifies long‐standing ambiguity in the generic boundaries of Eurytoma and provides a practical phylogenetic and morphological reference for placing newly described species and previously unassigned taxa within species groups.
Park et al. (Wed,) studied this question.