Q: I’ve been crushing Japanese beetles as I pick them from my plants, but I heard that might attract more beetles. Is that true?
A: The act of crushing Japanese beetles doesn’t attract more beetles, so you may continue to hand pick and crush the beetles.
Japanese beetles are attracted to various scents including pheromones released by other living Japanese beetles, volatiles produced by plants when the beetles feed on them, certain floral scents and the fragrance used in Japanese beetle traps, which mimics their natural pheromones.
While well intentioned, Japanese beetle traps often end up attracting more insects than they catch so their use is not recommended. Adult Japanese beetles typically only cause aesthetic damage, so control is not usually essential for plants to survive. If you just can’t stand to look at chewed leaves, check out this link for more ways to manage Japanese beetles: tinyurl.com/h2fpdvcc
Write to the Missouri Botanical Garden’s Center for Home Gardening at plantinformation@mobot.org or the Horticulture Answer Service, 4344 Shaw Blvd., St. Louis, MO 63110.