I understand about the beetle larvae and have taken measure to kill the grubs.
However, in the event that my lawn application does not take, does anyone have a sure-fire way to protect the trees from the Japanese beetle?
It's easier to just pick them off (soapy water in a can works great - like the previous poster said).
Conventional bug zappers really don't seem to do much good to them.
JB's are known to like certain kinds of plants - like Roses for example. You might consider switching out plants to those that they don't like. Not a very practical solution, but there you go.
I tried netting some rose bushes once, trying to keep an outbreak controlled. All I ended up doing was stressing the bushes and reducing air flow (meant that I then had an out break of black spot in addition to the JBs. lol.
Sorry, not much help.. but you're on the right track.
yes, I have heard about killing the japanese beetle with hands. A friend of mine has the sorts of problems, but luckily the number of beetle aren't so many, the family got to do the killing in one afternoon, and do it everytime they see beetle.