Location: Application Technology Research Unit
Title: Development of an Odor-Based Trap Tree Strategy for Ambrosia Beetles Infesting Ornamental Nurseries Authors
Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 23, 2009
Publication Date: December 13, 2009
Citation: Ranger, C.M., Reding, M.E., Oliver, J., Schultz, P. 2009. Development of an Odor-Based Trap Tree Strategy for Ambrosia Beetles Infesting Ornamental Nurseries. National Entomological Society of America Annual Meeting, December 13-16, 2009, Indianapolis, Indiana. Technical Abstract: Exotic ambrosia beetles are increasingly being recognized as key pests of ornamental nursery stock, and Xylosandrus germanus is one of the most problematic species. Xylosandrus germanus has a wide host range, but deciduous trees are preferred over coniferous hosts. Xylosandrus germanus has an efficient mechanism for olfactory orientation and assessment, and can differentiate between differences in tree vigor. Stressed hosts are preferred over unstressed trees by X. germanus for colonization. Ethanol, a volatile compound released by stressed trees, is a primary cue for host-seeking X. germanus. Due to the importance of volatile cues in host-selection by X. germanus, an odor-based trap tree strategy has been developed to induce attacks on specific trees. Experiments have determined that forcibly injecting ethanol into living trees induces rapid and heavy attacks by X. germanus and other ambrosia beetles. A positive dose-response exists, such that the quantity of attacks increases with an increasing concentration of injected ethanol. Attaching an ethanol-dispensing lure to a tree or irrigating with ethanol fails to induce as many attacks as ethanol injection. In addition, bolts from ethanol injected trees attracts 3x more X. germanus than a standard ethanol lure, which indicates the tree injection technique shows promise for mass trapping beetles. Uninjected control trees adjacent to ethanol-injected trees are not attacked by ambrosia beetles, which indicates the tree injection technique may be useful for deflecting beetles away from valuable nursery stock. Additional studies are focusing on incorporating repellents and the trap tree tactic into a push-pull management strategy, whereby repellents push host-seeking beetles away from valuable nursery stock and attractants pull beetles into specific trap trees prior to their disposal.