Back in 2009, a study was published that had looked into how well various essential oils helped to repel Japanese beetles. Wintergreen was the best, followed by peppermint oil; a combination of the two were even more effective. These weren’t foolproof (some years yielded better results than others), but they were better than other essential oils at repelling Japanese beetles from traps baited with an attractant.
Back in 2009, a study was published that had looked into how well various essential oils helped to repel Japanese beetles. Wintergreen was the best, followed by peppermint oil; a combination of the two were even more effective. These weren’t foolproof (some years yielded better results than others), but they were better than other essential oils at repelling Japanese beetles from traps baited with an attractant.