Japanese Beetle Report

Japanese Beetles are eating here in central Iowa. They attack my Chinook hops first, then go for the grapes. I also have Cascade and Mt. Hood, they never bother them. Anybody else experience this?

I have Cascade here in PA and they do indeed eat them...voraciously.

I just read in Mother Earth News (June/July 2011) some techniques for controlling Japanese beetles with organic methods. It talked about chickens, ducks, and guinea fowl as great predators in the spring for the beetle larva. Also mentioned was creating habitat, such as bird houses, etc., for nesting pairs of robins and blue birds, which feed the insect to their young. Trap crops, like raspberries, might be something to consider, too. The article said that many commonly used prevention methods, like garlic-pepper spray, milky spore disease, pheromone traps and row covers, had high failure rates.

cram said:

I just read in Mother Earth News (June/July 2011) some techniques for controlling Japanese beetles with organic methods. It talked about chickens, ducks, and guinea fowl as great predators in the spring for the beetle larva. Also mentioned was creating habitat, such as bird houses, etc., for nesting pairs of robins and blue birds, which feed the insect to their young. Trap crops, like raspberries, might be something to consider, too. The article said that many commonly used prevention methods, like garlic-pepper spray, milky spore disease, pheromone traps and row covers, had high failure rates.

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Spring methods do nothing for Japanese Beetles. The beetle larvae go underground in mid to late summer and do not emerge until the following summer. So unless those ducks and foul can pick up a shovel and scoop to get at the grubs, not much help in that respect.

Nematodes and milky spore have also not shown to be effective against them despite the common suggestion of use in organic articles.

You can use pheromone traps to lure the beetles away from your hops (or other infested plants), the problem is that they can lure beetles to your yard from pretty far away and in the long run lead to a worse problem. One of the biggest hurdles to controlling Japanese Beetles is that they live in and hatch out of the ground, you can only control the grub population in your yard, if your neighbor doesn't or even several houses down you will still have Japanese beetles.

Kaz said:

You can use pheromone traps to lure the beetles away from your hops (or other infested plants), the problem is that they can lure beetles to your yard from pretty far away and in the long run lead to a worse problem. One of the biggest hurdles to controlling Japanese Beetles is that they live in and hatch out of the ground, you can only control the grub population in your yard, if your neighbor doesn't or even several houses down you will still have Japanese beetles.

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Yep, GrubX in late summer every year... and talk all of your neighbors into it too, even if it means you taking a spreader over and doing their yard.

And talk the neighbors at the other end of the block into those pheromone traps

Ive been having issues as well here in southern KY, try either Seven Dust...I know some people dont like the stuff. If you dont there is a new item I have found that is food grade.

Food grade diatomaceous earth. Its basically ground up fossils. It'll kill all kinds of small pests, I used it for ticks and fleas first and it did wonders. Its even safe to feed to dogs. Mine had fleas really bad, even to the point they had eaten some. I was afraid they would get tape worm so I read you can feed it to dogs and it will make sure they dont get the worms. Its amazing stuff. Just sprinkle it on the plants and it will kill the bugs and larva.

Here in Iowa as well, they are chewing up my cascade, Willamette and centennial.

I go out most every night and brush them off into a bowl of soapy water. It kills them but over all seems kind of futile, but feel like it helps. They're really docile around 8pm or so.

Can get about 10 a night this way.

The grubs can be nasty, they literally killed our entire back yard last year. We had to rake out and re-seed about .25 acres and they had started on the front yard. We discovered the infestation in September, the grubs were quite close to the surface then and we applied a straight up grub killing poison. 12 hours later, hundreds if not thousands of dead and/or dying grubs coming up out of the ground. It was a shame, when we moved into this house 2 years ago, the lawn almost looked like a golf course. Sadly, that is what the beetles look for to lay their eggs...lush green lawns, go figure. Now that we have half of the yard green again, we treated with GrubEx in mid-May and will continue to do so. But like Randar and I said, its only good for your yard and you can't make your neighbors put it down. Pulling the beetles off and putting them into soapy water is the best bet for small infestations, but you have to keep on top of them. I've found that even a few beetles can't make a mess of hop leaves and cones.

I do the beetle-into-soapy-water thing as well, but really, the beetles congregate on my pole beans and rose bush, so I have found that keeping something they like even better than the hops in very close proximity has been the most effective method of keeping them off the hops.

Companion planting has worked for me so far the past 4 years.

So, I had to stop lurking.... I do insect and disease control on big estates and see Jap beetle all the time . Previous posts were correct in saying that controlling the grubs in your turf does not necessarily mean no beetles, they can fly for miles. That being said if you know that you have jap beetles in your turf, milky spores will work if appplied on a misty cool day early in the spring. But milky spore only works on jap beetles and depending what part of the country you live in there are 10 to 30 different species of white grub that can damage your turf.

DO NOT USE PHEREMONE TRAPS! There is a bunch of university research backing this up, you attract more beetles than you catch.

Evening soapy bucket taps are just about the best you can do if you desire organic hops. They are a pretty tough insect and will laugh at most organic pesticides. Permethrin will work well but most formulations have an additive that is pretty nasty.. piperonalbutoxide I think is the name, so be cautions of insecticides labeled "natural" as most chrysanthemum (permethrin and pyrethrin) derivatives have piperonalbutoxide in them.

Jap beetle does have a pretty short flight time so unless they are skeletonizing more than 30 % of your leaves I would just leave them alone. Hops are tough vigorous plants and will shrug off a couple munched leaves and plow forward.

Its not the munched leaves that bother me, they seem to be eating holes in my cones...that's war.

I have had Cascade and Mt. Hood for 3 years now and they have never taken even one bite out of them. The Chinook bine is 6ft away and they always destroy it. I go out with a bucket everyday and gather as many of them as I can and burn them. Also, there is some vine that grows in my yard that they may like even more than hops it has 5 leaves and is a pest that I must fight back every week or it will take over the place, I will post pics later.

To date, I've had 2 leaves from my Cascades fall victim to the beetles. For some reason, they haven't come back since I crushed those few buggers that I caught in the act. Not that I'm complaining!

Last year I had to rip my pole beans out of the garden because there were literally hundreds of beetles having a feast/orgy on them nightly. I tried nematodes early this spring, so I don't know if this made the difference (doubt it).

Reno_Raines said:

I have had Cascade and Mt. Hood for 3 years now and they have never taken even one bite out of them. The Chinook bine is 6ft away and they always destroy it. I go out with a bucket everyday and gather as many of them as I can and burn them. Also, there is some vine that grows in my yard that they may like even more than hops it has 5 leaves and is a pest that I must fight back every week or it will take over the place, I will post pics later.

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does the wild vine look like this? if so what is it and what will kill it.. it's taking over my yard.

Yes. That is the same stuff I have. The people I bought the house from 6 years ago actually planted it and were proud of it. I didn't know any better and also forgot the name. I just rip it out of the ground every few weeks, it grows faster that anything I have seen.

Sevin insecticide seems to work on Japanese Beetles, I used it extensively last year and there seem to be fewer beetles this year.

Reno_Raines said:

Yes. That is the same stuff I have. The people I bought the house from 6 years ago actually planted it and were proud of it. I didn't know any better and also forgot the name. I just rip it out of the ground every few weeks, it grows faster that anything I have seen.

Sevin insecticide seems to work on Japanese Beetles, I used it extensively last year and there seem to be fewer beetles this year.

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a friend of mine said it's called Virginia Creeper.. I call it a pain in the arse

It may sound odd, but I thought reviving this thread makes sense because fall is the best time to treat the soil for Jap beetle grubs. Most people only get concerned when they see the adults in June, but in reality the grubs are chewing the crap out of the roots now til summer. Just a friendly reminder - now is a good time to apply a grub control.


Also, I think using a trap plant (a plant they like to chew on even better than hops) strategy, combined with soil treatments is the way to go.
Some plants I know they love are: grapes, Hardy hibiscus, Linden trees (basswood), Cherry trees, and Rose of Sharon. There has to be more - add to the list if you can.
The idea is to plant a couple of these target plants nearby. If you have prevailing winds in your area , put them downwind from the hops - because the beetles fly into the wind following scents and odors. This intercepts the beetles before they reach the hops. Treat these plants with Orthene Tree-n-Shrub spray on a regular schedule to kill them as they feed. This strategy doen't work 100%, but in areas with high populations of beetles, it makes a significant impact. Growers who are trying to grow organically are probably cringing right now, but you still are growing organic hops because you are not treating the hop plant itself. (For certified organic sites I know this is not an acceptable practice, but my point is to offer a working solution to an average homeowner whose hops are getting chewed to pieces each year) I use this strategy with treated grape vines and Rose of Sharon in our commercial production and it works well. It only attracts beetles in the immediate area; not from the whole neighborhood like phermone traps do.