The Japanese Beetles (Popillia japonica) are back... I know I was all excited about being a Humane Backyard, but I checked the paperwork and insects are not listed for nonlethal resolutions to their presence. As I have said before, I do not spray anything but Neem Oil and soapy water, but with this many Japanese Beetles, I have resorted to handpicking them or knocking them off the plant into a coffee can with an inch of water before killing them. Also, I have noticed leaving a few crushed beetles around the roses does seem to discourage any surviving beetles from returning for a couple of days.
I have to admit that these bugs do creep me out with their front legs splayed like pincers, and they frequently fly in your face if you miss squishing them too. Every year they seem to target a different selection of plants; this year the Knockout roses, echinacea, butterfly bush (Buddleia) flowers, and surprisingly, only the yellow gladiolas seem to be their menu favorites. My son's poor nectarine tree is also infested, so I think this will be another year we see the fruit feeding nature instead of us.
These destructive insects emerge from the soil, where they have spent a year as white grubs underground. Historically, the Japanese beetle arrived from Japan before 1912, since then the beetle has spread west and north from New Jersey. See here https://en.wikipedia.org/wiki/Japanese_beetle
So, while these beetles are doing their best to eat through my roses, I am committed to smooshing them before they complete the egg laying portion of their life cycle. I am sure this battle will end up at best a draw, more likely, I will make little impact in their population. In my gardening notebook I will highlight the timing of my Neem oil application next year for a late June hatch. Hopefully, the spraying and my squishing efforts this summer will create a smaller population of Japanese beetles next year.