Eurytomids are small parasitic wasps associated with many communities of phytophagous insects. In most cases, the accurate identification of eurytomids is impeded by inadequate species descriptions that do not include figures of diagnostic features, and keys that are difficult to use. Here, diagnostic features and redescriptions are provided for both sexes of the eurytomids associated with galls induced by cynipid wasps of the genus Diplolepis Geoffroy found on shrub roses across Canada. Consequently, six species of Eurytoma Illiger, along with Tenuipetiolus ruber Bugbee, are dealt with. One new species, Eurytoma shorthousei Zhang & Gates, sp. n., is described. Two species are synonymized, E. hebes Bugbee, 1973 and E. spina Bugbee, 1951 under E. longavena Bugbee, 1951, syn. n. Several new host and distribution records are reported. A dichotomous key is provided for both sexes of all seven species using photographs and scanning electron microscopy images.