Location: Systematic Entomology LaboratoryTitle: Testing species limits of eurytomids (Hymenoptera: Eurytomidae) associated with galls induced by Diplolepis (Hymenoptera: Cynipidae) in Canada using DNA barcoding Author
Submitted to: The Canadian Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2013
Publication Date: 7/23/2013
Citation: Zhang, Y., Gates, M.W., Shorthouse, J.D. 2013. Testing species limits of eurytomids (Hymenoptera: Eurytomidae) associated with galls induced by Diplolepis (Hymenoptera: Cynipidae) in Canada using DNA barcoding. The Canadian Entomologist. 146:1-14. Interpretive Summary: Many wasp and fly insect pests induce deformities on plants called galls that can detract from their horticultural or agricultural value. These galls are attacked by parasitic wasps, important components of agricultural and natural ecosystems that provide natural control of pestiferous gall inducers, savings millions of dollars annually. Gall communities also serve as important model systems for studying food web relationships among insects. In this paper, we report on parasitic wasps associated with wasp-induced galls on roses in Canada, using the DNA barcodes and morphology. Three species of parasitic wasp were shown to be identical and another species to consist of multiple, externally indistinguishable species. This information will assist a broad array of scientists and ecologists in identifying and better understanding the relationships, evolution, and feeding habits of these wasps.
Technical Abstract: The study of insect host-parasitoid relationships are often confounded by the difficulties associated with species delimitation in taxonomically challenging groups. Eurytomids (Hymenoptera: Eurytomidae) are the most common parasitoids associated with rose galls of Diplolepis (Hymenoptera: Cynipidae) in Canada, 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 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 complex, as three species were shown to be synonymous. The results also revealed the presence of cryptic species within Eurytoma spongiosa. Furthermore, issues that have long impeded ecological and biological studies on eurytomids on rose galls such as host specificity and sex association were readily resolved using the integrative approach, providing new insights into the evolutionary history of this difficult group.