We have had huge swarms of JB's for the past 5 years. Almost none this year. A good thing.

I believe a natural control is some type of fungus. One of the control methods you will find is to spray something called "milky spore" on the ground. Always thought that silly as they will move a half mile or more to come join the party at your place. So spraying your yard would be pointless. But it seems the JB's have a pattern of moving in, exploding, then dying out over time. It may be that it takes that long for natural control of "milky spore" or whatever that is to catch up with them as they spread.

Or with all the rain we had this year, maybe they all drowned?

For past 2 years, we have been using a nicotine product on plants we want to protect and let the others go.  Nicotine is toxic to them and is absorbed into the leaf. They eat the leaf and die. Seems to be working.

AcFordHawk wrote: Japanese beetles working over the plants in the yarden.  They seemed to take a big liking to the raspberries this year.  Spray what plants I can and placed a couple of the Bonide beetle traps - capture bag to bag and a half every day.

I quit trapping them.  One sure way to attract them.  Now if you could convince the

neighbor to set out traps. 

About 5 years ago when our beetles hit hard, local University held a seminar on research they had been doing. Seminar focused on traps and they gave us information on commercial beetle traps used to monitor commercial crops. These were hard plastic funnels that came with male and female attractors, and were to be fitted on quart sized bottles. they had modified them to fit on 30 gallon trash cans.

I fit them to 5 gallon buckets and on a good day, could fill 5 to 8 buckets from that many traps. Made no difference.....damage was still severe. Tried composting them with no luck.

I suggested they should try putting traps out on a body of water and letting fish eat them. They said they had tried that and first day worked well, then fish got full and stopped eating. Beetles stacked up on water.....at first rolling balls of them until they drowned, they turned into a carpet of dead floating beetles that screwed up the lake for weeks.

What they also mentioned was that spray with nicotine. Active ingredient is acemitaprid.....sold as Ortho Fruit and Vegetable spray. Amish I know use same product sold as dry powder (Assail) on squash and melons to control squash bugs.

Nicotine is absorbed into the plant so it doesn't wash off. Bug eats plant, nicotine is toxic to them and kills them. Otherwise harmless to things like bees. But apparently Ortho got complaints and took their product off the market. So nicotine products hard to find and expensive.

Turns out there are 3 versions.......the mild one we use.......a more potent and lasting version you pour on the tree bark, where it is absorbed into cambium layer and distributed to vegetation.....and a 3rd version you pour on the soil around the drip line. Is absorbed through the roots. That one is season long.

So we went to spraying trees and plants we wanted to protect (like my pole beans, apples trees, etc) and let the other ornamental trees, like a pin oak, go. Didn't stop them, but minimized the damage.

What occurs to me is if a guy could get some of the heavy duty stuff, they could treat a sacrificial tree somewhere out in the distance........say a big pin oak tree in a fence line on the back side of your property........then at that same tree, use the female scent attractor at that tree. Get the females to come to that sacrificial tree, they eat the leaves, it kills them. By killing off the females, no new bugs next year.