For the second year, we're seeing practically no Japanese beetles.
Two years ago, my wife and I could spend hours of quality time together, picking the beetles off our sand cherries, shrub roses and dwarf crab tree. I don't know if we had any real effect, but drowing the bugs in a jar of soapy water was somewhat satisfying.
So far this summer, we've managed to find just two. Last year was also practically bug free.
We're not doing anything different, but the winters have been particularly nasty.
We had several extended periods of cold, a week or more where the temperature never got above 0F.
There were many reports of municipal water supply lines freezing, even though they're buried 6 feet or more. The city suggested that if the cold water temp got to 36F or below, leave a faucet at a trickle to prevent freezing. The one time I checked ours, it was at 38F.
Since these conditions were region-wide, maybe we'll see a drop in beetle population for the next few years.