Testing species limits of Eurytomidae (Hymenoptera) associated with galls induced by Diplolepis (Hymenoptera: Cynipidae) in Canada using an integrative approach

Abstract

AbstractStudies of insect host-parasitoid relationships are often confounded by the difficulties associated with species delimitation in taxonomically challenging groups. Eurytomidae (Hymenoptera) are common parasitoids associated with galls induced by Cynipidae (Hymenoptera) and are difficult to identify due to their small size, morphological conservatism, and unreliable published host records. This study tests the species limits of eurytomids associated with galls induced by Diplolepis Geoffroy (Hymenoptera: Cynipidae) in Canada using an integrative taxonomy approach including adult morphology, the mitochondrial gene cytochrome c oxidase I, host records, and geographical range. Incongruences between morphological and molecular data were found within the Eurytoma discordans Bugbee complex, as Eurytoma discordans, Eurytoma acuta Bugbee, and Eurytoma calcarea Bugbee were shown to be new synonyms. The results also revealed the presence of cryptic species within Eurytoma spongiosa Bugbee. Furthermore, issues that have impeded ecological and biological studies of eurytomids associated with rose galls such as host specificity and sex association were resolved using DNA barcodes, providing new insights into the evolutionary history of this difficult group.