Evaluation of lure combinations containing essential oils and volatile spiroketals for detection of host-seeking Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

Authors: OWENS, DAVID - Orise Fellow; Montgomery, Wayne; Narvaez, Teresa; DEYRUP, MARK - Archbold Biological Station; Kendra, Paul

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2017
Publication Date: 7/28/2017
Citation: Owens D., W. S. Montgomery, T. I. Narvaez, M. A. Deyrup, and P. E. Kendra. 2017. Evaluation of lure combinations containing essential oils and volatile spiroketals for detection of host-seeking Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae). J. Econ. Entomol. 110(4):1596-1602.

Interpretive Summary: The invasive redbay ambrosia beetle (RAB) carries a fungus that causes laurel wilt, a lethal disease of trees in the laurel family, including forest species (like redbay and swampbay) and avocado, an economically important fruit crop. Effective lures are needed for early detection of RAB and implementation of control strategies. Lures containing cubeb oil are the current standard for RAB, but other essential oil lures are commercially available for RAB, as well as attractants for other species of ambrosia beetle. Scientists at the USDA-ARS (Miami, FL), in collaboration with Archbold Biological Station (Lake Placid, FL) conducted field studies to compare efficacy of essential oil lures and new combinations of beetle lures. Results indicated that a lure containing 50% alpha-copaene was the most effective essential oil lure available. However, a combination of oil lure, volatile spiroketal, and low-dose ethanol was more attractive than the oil lure alone, indicating that further improvement may be achieved by using multi-component lures. This information will benefit action agencies that monitor for RAB and other pest ambrosia beetles.

Technical Abstract: The invasive redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen (Raffaelea lauricola) that causes laurel wilt, a disease responsible for widespread mortality of trees in the Lauraceae in the southeastern U.S. Early detection of incipient vector populations may allow for management practices that could successfully mitigate damage. Developing new, highly effective attractants is a priority for improving sensitivity of early detection efforts. In this study, two field tests were conducted to evaluate combinations of commercially-available bark and ambrosia beetle lures for enhanced attraction of host-seeking female X. glabratus. In addition, lures were compared for capture of non-target scolytine beetles. In the first experiment, traps baited with a combination of cubeb oil, conophthorin, chalcogran and ethanol captured greater numbers of X. glabratus than cubeb oil alone, the current standard attractant. However, this combination lure resulted in higher non-target scolytine captures than with the cubeb lure. In the second field test, an oil enriched in the sesquiterpene a-copaene caught significantly more X. glabratus than other lures currently available for monitoring this pest. There were no differences in efficacy between cubeb oil lures produced by two different manufacturers, and a combination lure containing copaiba and cubeb oils did not increase captures over the cubeb lure alone. Results of these two tests suggest that increased sensitivity for detection of X. glabratus may be achieved with a multi-component lure that incorporates a-copaene, spiroketals, and low release of ethanol.