Attraction of the redbay ambrosia beetle, Xyleborus glabratus, to key fungal and host plant odors

The redbay ambrosia beetle, Xyleborus glabratus, is an invasive beetle that has become established in the southeastern United States and transmits a fungus, Raffaelea lauricola, that causes lethal laurel wilt. Among the susceptible Lauraceae hosts are redbay, Persea borbonia and avocado, Persea americana. We analyzed the volatile emissions of R. lauricola and redbay wood and tested synthetic odor blends as a potential attractants in a natural redbay forest infested with X. glabratus. In initial trials, the synthetic Raffaelea odor blend was not attractive to the beetles by itself; however, traps baited with the Raffaelea odor paired with manuka oil lures captured 56% more beetles on average than manuka lures alone. Redbay odors consisted significantly of eucalyptol, cymene, and a-pinene.  We conducted trapping experiments using subtractive blends and found that eucalyptol was necessary for capturing X. glabratus. High release of eucalyptol caught similar numbers of X. glabratus when compared to trap capture baited with manuka.