Ethanol-injection induces attacks by ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) on a variety of tree species

Authors: Reding, Michael - Mike; Ranger, Christopher; OLIVER, JASON - Tennessee State University; SCHULTZ, PETER - Virginia Polytechnic Institution & State University; YOUSSEF, NADEER - Tennessee State University; BRAY, ALICIA - Central Connecticut State University

Submitted to: Agricultural and Forest Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2016
Publication Date: 8/10/2016
Publication URL: http://handle.nal.usda.gov/10113/5801828
Citation: Reding, M.E., Ranger, C.M., Oliver, J.B., Schultz, P.B., Youssef, N.N., Bray, A.M. 2016. Ethanol-injection induces attacks by ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) on a variety of tree species. Agricultural and Forest Entomology. DOI: 10.1111/afe.12178.

Interpretive Summary: Invasive ambrosia beetles are serious damaging pests in North American ornamental nurseries. The beetles attack trees by boring into the stems/trunks making trees unsalable or killing them. Research on ambrosia beetles has been difficult because attacks on experimental trees have been unreliable. The ethanol-injection technique developed by our lab induces reliable ambrosia beetle attacks on experimental trees. Ethanol-injection of live trees has facilitated research on biology, ecology, and behavior of ambrosia beetles in ornamental nurseries. In addition, the technique could be used to develop management strategies that attract beetles away from salable trees, help growers synchronize their sprays with beetle activity, or improve efficacy of control sprays by reducing attack pressure on salable trees. However, most research has been performed on one species of tree, sweetbay magnolia. In order to develop practical management strategies based on ethanol-injection, the technique must be effective on a variety of trees. Sixteen species of trees were tested and ambrosia beetles readily attacked every species. Furthermore, the technique worked effectively in three different states. Our research shows that ethanol-injection should reliably induce attacks by ambrosia beetles on a wide variety of deciduous trees. This information should help advance research on biology, behavior, and ecology of ambrosia beetles in ornamental nurseries. In addition, the results indicate that ethanol-injection could be used to reduce attacks on salable trees by attracting beetles to trees designated for culling.

Technical Abstract: Exotic ambrosia beetles have become serious pests in ornamental tree nurseries. Injecting Magnolia virginiana L. with ethanol has reliably induced attacks by exotic ambrosia beetles to facilitate research on their biology and management. In the current study, ethanol-injection was tested on a variety of tree species to determine whether the technique would effectively induce attacks on a range of ornamental species. Experiments were conducted in Ohio, Tennessee, and Virginia, and included a total of 16 species of deciduous trees in 11 families. Ethanol-injection reliably induced attacks by exotic ambrosia beetles on all species of trees tested. There were differences in total attacks by ambrosia beetles among trees in most experiments, but no species of trees were consistently the most or least attacked in repeated experiments. Bark tissue samples indicated attacks were most likely related to ethanol uptake and emission. In Ohio, Xylosandrus germanus (Blandford) was the most common species attacking trees and attacked all species of trees tested. In Tennessee, Xylosandrus crassiusculus (Motshulsky) and Cnestus mutilatus (Blandford) were the most common species attacking the trees, and they attacked all species of trees tested. Results indicate ethanol-injection reliably induces ambrosia beetle attacks on a wide range of deciduous tree species. This information should further facilitate research on ambrosia beetles because experiments will not be constrained to only one or a few potential hosts, and might facilitate development of behavior-based management tactics that integrate manipulating ambrosia beetles away from saleable nursery trees.