Location: Systematic Entomology LaboratoryTitle: The impact of native hyperparasitoids on winter moth (Operophtera brumata) biological control Author
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2018
Publication Date: 1/31/2018
Citation: Broadley, H.J., Kelly, J., Elkinton, J.S., Kula, R.R., Boettner, G.H. 2018. The impact of native hyperparasitoids on winter moth (Operophtera brumata) biological control. Biological Control. 121:99-108. Interpretive Summary: Parasitic wasps attack crop and forest pests that cause billions of dollars of damage annually. The parasitic wasps treated in this paper attack a fly used for biocontrol of winter moth, an exotic invasive forest pest in North America that also causes damage to blueberry, apple, and cranberry. This research uses morphological features and DNA sequence data to determine the identities of wasps that attack the biocontrol fly. The extent to which the wasps contribute to fly mortality is assessed. The potential for the wasps to negatively impact the fly’s ability to control winter moth is discussed. This paper will be useful to scientists conducting research on winter moth, personnel responsible for controlling and regulating winter moth, and personnel generally involved in pest management.
Technical Abstract: High mortality to introduced parasitoids from disease, predation, and hyperparasitism (parasitism of a parasitoid) can interfere with insect biological control efforts and result in unsuccessful management of the targeted invasive species. Cyzenis albicans (Fallén) is a tachinid fly that has been introduced to the northeastern U.S. as a biocontrol agent of the invasive Lepidoptera species winter moth (Operophtera brumata, L.). This study aims to determine the rates of mortality and hyperparasitism of C. albicans puparia, identify the hyperparasitoids present in the system, and consider the impact of hyperparasitism on the potential success of the biological control of winter moth by C. albicans. Mortality of C. albicans puparia was primarily due to predation but also to hyperparasitism. Predation and parasitism rates on C. albicans puparia were consistently high across the six study sites and three years of study but somewhat lower than those reported from British Columbia, where successful establishment of C. albicans in the 1970s was followed by a decrease in winter moth densities. In this study, three hyperparasitoids were found: Phygadeuon sp., Pimpla spp. and Gelis sp. All are ichneumonids known to include generalist hyperparasitoids. We conclude that while total mortality and hyperparasitism of C. albicans is high, it likely does not have a significant effect on the biological control of winter moth in this system; however, it may explain why C. albicans has been slow to establish. Our study emphasizes the importance of considering the role of mortality from predators and hyperparasitods to the biological control agents.