Cures for Japanese Beetles

[Daisy8s]

For the first year I'm being plagued by Japanese Beetles. I have seen that they'll drown in water buckets and I've read that beer is a good lure for drowning. In my first experiment I didn't have any beer on hand so I used some hard lemonade. It seemed to work alright...maybe slightly better than plain water, but nothing was getting more than 4-5 beetles per day.

Today I began a second experiment. I put out two containers that were a mixture of beer and water and one container that is plain water. All three containers are under a different rhubarb plant...which are my hardest hit plants. I'll report back if there is a difference in findings between beer/water mixture and plain water.

Anyone have any more advice on how to kill them? I find them especially frustrating because I cannot find the darn things...I only see the damage they cause. With potato slugs I could find them or their eggs easily but I only knew I had these beetles because they showed up drowned in a bucket of water and then I looked up what they were.

Will Diatomaceous Earth kill these beetles or their larvae? I like to be organic but I'm not against some chemicals if truly necessary.

Thanks.

 

[Daisy8s]

So, to report on the first day of the experiment. I checked about 24 hours after putting out the beer and water and found that the two containers with the beer/water mixture each had 2-3 beetles in them whereas the plain water container had none.

Incidentally, all three containers are in a straight line, each about 3 foot from the next container. The plain water container is in the middle with the beer containers on the ends. Each container is under one rhubarb plant (there are three plants).

Today I did spot several of the beetles on the leaves...the first time I've seen them. I was out there about 6pm so perhaps this is a time when they are active?

If anyone else has advice about killing these bugs I'm all ears!

 

[WorkingWith]

I've had a a few problems with Japanese beetles over the years and I've had some success with the following.

Japanese beetles send scouts out so hand picking them and destroying them before they can call friends. They are less active during the early morning and late evening. Crushing or dropping them into soapy water has always worked for me.

Some science supply and greenhouses will sell scented attractants that will lure them in and get them stuck. problem with attractants is that unless you and your neighbors all use them you may end up drawing in more beetles.

Another options is planting plants that the Japanese beetles does not like, these include ageratum, arborvitae, ash, baby's breath, garden balsam, begonia, bleeding heart, boxwood, buttercups, caladium, carnations, Chinese lantern plant, cockscomb, columbine, coralbells, coralberry, coreopsis, cornflower, daisies, dogwood (flowering), dusty-miller, euonymus, false cypresses, firs, forget-me-not, forsythia, foxglove, hemlock, hollies, hydrangeas, junipers, kale (ornamental), lilacs, lilies, magnolias, maple (red or silver only), mulberry, nasturtium, oaks (red and white only), pines, poppies, snapdragon, snowberry, speedwell, sweet pea, sweet-William, tuliptree, violets and pansy, or yews.

Personally i use the hand picking method as I'm in my garden every morning and night. I check my pants over give them a shake see if anything falls out.

Hope this helps.

Matt Olsen
Working With
All it takes are two hands and a plan.

 

[Mattemma]

I am hoping the predator wasp they are trying on JPs comes to market soon. I love using one creature to eat another.

Last year I sprayed water mixed with the dogs flea and tick shampoo.This year I just shake them in a bucket,and feed them to the hens. The JPs are eating my rose of sharon flower buds.

 

[chickness]

My neighbor has a fence line of Rose of Sharon which the japanese beetles love. She uses a mild soapy spray on her trees which seem to keep the numbers down, and she says the plants acually grow nicer because of it. I do what most others say on the post. At first I was going around the yard each morning, taking a big bucket of soapy water, and shaking the leaves while I watched the bugs dropped. Now I don't add the soap, and take a small container of water and catch the buggers. My 3 chicks didn't like them when they were a few months old...but just this week now at 4 1/2 months old, the girls decided they loved them!!!! ah, beautiful creatures. I think every person needs back yard chickens so that we can diminish the japanese beetle problem! I heard via radio the dry weather could help with diminishing the numbers a bit in southern wi, and they have been gradually decreasing here, though it doesn't seem like it.....they are still increasing in Green Bay and north. I wouldn't resort to using grub killer on your lawns, or attracting them with the bags. If you have the time, it's kinda of relaxing and gives you an excuse to look closely at the things growing in your yard while drowning them. Even the npr garden expert said there is really not much you can do to eliminate them....but it sure is fun watching the girls gobble them up!

 

[Daisy8s]

Thanks for the tips, everyone!

The experiment continues with more success. Switching to straight beer (not a mixture of beer and water) clearly drew in even more beetles. After a few days I had 10+ beetles in each beer container and only 1 in the straight water container.

I've also started walking around hand picking them. I learned that they can fly! Geez, i sure wasn't expecting that the first time a bunch took off in my face! But, after a rain or in the early morning dew they seem pretty lethargic. Yes, it is a nice interlude to putsy around picking them off and at least it's a bit less gross than picking potato bugs in the larvae stage.

I let my flock into my garden this week because everything is up enough that they won't demolish new sprouts yet it's too soon for my tomatoes to be ripening up much. The birds got really excited when I dumped out the beer containers to refresh the beer--gobbled up those marinated beetles like they were a delicacy! I'm hoping they got the taste now and they'll hunt them down for themselves.

The beetles had moved on from my rhubarb to my bean plants. I was interested to see that although I'm trellising beans, sweet potatoes and cucumbers in the same area the beetles only went for the bean leaves. Literally bean and sweet potato vines are completely intertwined yet only the bean leaves have holes. The sweet potato leaves are a bit thicker--maybe less palatable? I moved a beer container into that area and hope it begins to help.

 

[dirtworksone]

Spinosad will kill the beetles and Milky Spore will kill the grubs they come from as well as nematodes. We have all of these things available at Dirt Works online store.
Something mechanical you can do is this. Japanese beetles aren't good climbers. you can often find them at the tops of the plants in the morning. If you shake the plant they fall off pretty easily and have to spend the day climbing back up which makes them tired. It's not a cure, just a deterrent until you get them under control. Also, do what you can to attract birds to the yard that eat them. Wildlife can be a real asset to a garden or farm if managed properly.

 

[Whittni]

A baggy of water with a single penny in it will have 30+ drown. (hang it up with top unzipped)