| Summary: | The redbay ambrosia beetle, <i>Xyleborus glabratus</i>, was detected in Georgia, USA, in 2002 and has since spread to 11 additional states. This wood-boring weevil carries a symbiotic fungus, <i>Harringtonia lauricola</i>, that causes laurel wilt, a lethal disease of trees in the Lauraceae family. Native ambrosia beetles that breed in infected trees can acquire <i>H. lauricola</i> and contribute to the spread of laurel wilt. Since 2002, laurel wilt has devastated native <i>Persea</i> species in coastal forests and has killed an estimated 200,000 avocado trees in Florida. Since laurel wilt is difficult to manage once it has entered a susceptible agrosystem, this study evaluated piperitone as a candidate repellent to deter attacks by <i>X. glabratus</i> and other ambrosia beetles. Additionally, piperitone was compared to the known repellent verbenone as a potential cost-effective alternative. The repellent efficacy was determined by comparing captures in traps baited with commercial beetle lures containing α-copaene versus captures in traps baited with lures plus a repellent. In parallel 10-week field tests, the addition of piperitone reduced the captures of <i>X. glabratus</i> in α-copaene-baited traps by 90%; however, there was no significant reduction in the captures of native ambrosia beetles in ethanol-baited traps. In two replicate 10-week comparative tests, piperitone and verbenone both reduced <i>X. glabratus</i> captures by 68–90%, with longevity over the full 10 weeks. This study identifies piperitone as a new <i>X. glabratus</i> repellent with potential for pest management.
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