Answer: Unfortunately, Japanese beetles are very difficult to control because they fly long distances. The Sevin contains carbaryl which is effective, however it is a contact insecticide and has no residual action. You can try to repel them using a spray containing neem. You can also hand pick them off the plants early and late in the day when they are sluggish, drop them into soapy water. You can also try to combat them at the grub stage by treating over a large area with beneficial nematodes or milky spore disease. This approach works better if an entire neighborhood works together to treat an extended area. The traps are not recommended as they tend to attract more beetles than they catch. I wish I could be more encouraging.
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