OOOHHH! Those nasty little buggers. They are out of control! First they were devouring our hibiscus trees and roses- at the shop- and then they decided to attack our Contorted Filbert tree at the house. We tried the Neem sprays and I don't have time to stand around all my plants knocking the invaders into soapy water or spraying all my plants- repeatedly with a soap concoction. So, I opted for the bag ( now sold out at The PURE Gardener, but we do have the refill bags ).
The way to reduce the beetle's population, if it’s possible at all, is to reduce the population of grubs they come from, with natural inoculates like beneficial nematodes or Milky Spore. The Japanese Beetle is the adult stage of a grub that starts out underground.I've applied Milky Spore ( available at the shop) to my yard last fall but haven't re-applied the additional treatments needed to knock out the nasty intruders. I am going to opt for the beneficial nematodes ( available at the shop ) treatment. Both Milky Spore and Beneficial Nematodes need to be applied in the Spring and Fall. The Japanese Beetle emerges from the ground- like a bad Godzilla movie, or Godzilla vs. Turtle Monster, anyway-in June and retreats back into the ground sometime in August to lay its eggs and start the cycle all over again. So the madness is almost over! Then it is our small window of opportunity to fight back. I have used Beneficial Nematodes in my back vegetable garden around my garlic a few years back and had success. A fall day like today, a rain day, is perfect for watering in the microscopic beneficial invaders. They multiply (in the ground) on their own and also go after other nasty pest like flea eggs which will make my 4 chihuahuas happy! What horrors are you experiencing with your own gardens? I would love to hear about your battles!