Answer: Some people have had success using neem-based products to deter the beetles. Be sure to read and carefully follow all of the label directions and make sure the specific plants you wish to spray are listed on the label. You could also consider planting only things that are least attractive to them, thus creating less of an invitation. You could also consider introducing some of the beneficial nematodes or milky spore disease to stop them at the grub stage, although I am not sure if that would be included within the humane parameter it does use a naturally occurring control method. Here is some additional information about them that you may find interesting. You may need to cut and paste the complete url into your browser to make it work correctly.
I hope this helps.
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