I live in the Chicago area & also remember JB's being particularly bad in 2012 & not as bad last summer. I've been planting two different properties
(mine & my elderly Aunt & Uncles's) everyday for a couple of weeks & encountered one grub, yesterday.

2011 & 2012 were terrible, the JB's ate the buds of my summer blooms before they even opened and they even skeletonized the leaves of many rose bushes, especially OGR's. 2013 the JB's were way down, I believe due to the drought during the summer before & I suspect the same will be true for this summer. Haven't seen any JB's so far this summer but they usually don't show up to the end of June & peak about the middle of July.

Thanks for bringing this up!
Here in Nottingham, we did not have a winter but a brutal summer last year with swarms of Japanese beetles and this year, we had too many rain storms and (I only it is only beginning) I saw only one beetle which was dead in a bucket of water. what affects their numbers?

We had a particularly bad year years ago. Or it could have been because I used those darn traps. Anyway, I had to resort to Sevin. Since then, there haven't be many to concern me. Not just in my yard, but all over this area. Now I did see two JBs just this week, so maybe the JB drought is over. I sure hope not.

I am in Southern Kentucky, and the beetles were horrible (for me) last year.

I was drowning Colorado Potato Beetle larvae off of my potato plants on Friday the 13th, and had a JB in my pitcher.

NoAcceptance,

Drought the season earlier decreases Japanese Beetle grubs. I think it is harder for them to bore into the ground, and for the eggs to hatch without moisture.

I am speculating that a 4' deep frost line helps keep them down, too. We shall see. But prior to two years ago when they were so numerous here, I would usually get multiple grubs in each shovel full I would dig in the garden. And I have seen only 1 or 2 beetle grubs, and that was in May.