s1mpl3k1d wrote: ↑September 28th, 2020, 8:56 am
What I will do next year is watch japenese beetles. I should have done something this year because I saw tons of them on my plants. I was really shocked because they vanished in 2013 but came back this year. Once I see them(I think it was June), I'm going to drop down grub preventative products like any products from the screenshoot(link you shared)
Personally, my preferred grub preventative is one with chlorantraniliprole, which is really only Scotts GrubEx at the current time unless using professional products. For human impact, chlorantraniliprole is in the safest category of pesticides (category 4), is much less likely to harm bees or earthworms, and has a long residual. The one drawback is that chlorantraniliprole has to be applied further in advance for best effectiveness, as mentioned in the MSU article. What I have in my notes is that the preferred application timing is right around April 30 for maximum effectiveness. (It's worth noting that April 30 is also exactly in the middle of the recommended MSU timing for applying chlorantraniliprole.)
The traditional standby for grub prevention is imidacloprid, but there is concern that it is harmful to bees and earthworms. I used to use it before GrubEx changed their formulation. It should be applied a little later in the season.
I haven't had a grub problem at all since regularly applying a preventative. This is definitely a case where an ounce of prevention is worth a pound of cure.
I should also note that neither imidacloprid or chlorantraniliprole will kill the adult japanese beetles that you will see flying around next June. Rather, these preventatives will kill the baby grubs that hatch from the eggs that the adult japanese beetles deposit in the soil in your lawn. The adult beetles don't actually hurt your grass. If you have a vegetable garden or ornamentals, well, that's a different issue...