Japanese Beetles

How to Identify and Get Rid of Japanese Beetles

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Use these tips to get rid of Japanese beetles.

Crestock

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What are those green garden beetles? Here are tips on how to identify and get rid of Japanese beetles.

What are Japanese Beetles?

Japanese beetles are small bugs that carry a big threat. They do not discriminate on what types of plants they feed on. In fact, they are classified as a pest to hundreds of different species. They are one of the major insect pests in the Eastern and Midwestern United States, causing monumental damage to crops each year.

Prior to the beetle's accidental introduction into the United States earlier in this century, the Japanese beetle was found only on the islands of Japan, isolated by water and kept in check by its natural enemies. In 1912, a law was passed that made it illegal to import plants rooted in soil. Unfortunately, the failure to implement the law immediately allowed the Japanese beetle to arrive in this country.

Most entomologists agree that the beetles entered the country as grubs in soil on Japanese iris roots. In 1916, these coppery-winged pests were first spotted in a nursery near Riverton, New Jersey. By 1920, eradication programs were dropped; the beetle proved to be too prolific a breeder. Not a choosy eater, it dines on over 200 species of plants.

Identification

How to Identify Japanese Beetles

Japanese Beetles are ½ inch in length with metallic blue-green heads, copper backs, tan wings, and small white hairs lining each side of the abdomen. Japanese beetles usually feed in small groups. They lay eggs in the soil during June, which develop into tiny white grubs with brown heads and six legs that are up to ¾ inch in length. These grubs will remain under wraps for about 10 months, overwintering and growing in the soil.

They emerge from the soil as adult beetles and begin feeding in June. They usually attack plants in groups, which is why damage is so severe. Although the lifecycle of the adult Japanese beetle is barely 40 days, it can cover a lot of ground. Even if you succeed in controlling your Japanese beetle population, your neighbor’s Japanese beetles might come on over.

Japanese Beetle Damage

Japanese beetles eat a wide variety of flowers and crops (the adult beetles attack more than 300 different kinds of plants), but they are especially common on roses, beans, grapes, and raspberries. They can devour most of the foliage on favored plants like roses. Look for leaves that are “skeletonized” (only have veins remaining). This is a tell-tale sign of Japanese Beetles. Mexican Bean Beetles can also leave foliage skeletonized, though, so be sure to identify them by their appearance as well.

Grubs damage grass when overwintering in the soil, as they eat the roots of lawn grasses and garden plants.

japanese-beetle-damage.jpg
Photo Credit: The Ohio State University. Japanese beetles cause leaves to appear skeletonized.

Control and Prevention

How to Get Rid of Japanese Beetles

Good horticultural practices, including watering and fertilizing, will reduce the damage caused by these beetles, but oftentimes you simply need to get rid of them. Here are some ideas:

  • Row Covers: Protect your plants from Japanese beetles with row covers during the 6- to 8-week feeding period.
  • Hand Pick: Unfortunately, the most effective way of getting rid of Japanese beetles is to hand pick them. It’s time consuming, but it works, especially if you are diligent. When you pick them off, put them in a solution of 1 tablespoon of liquid dishwashing detergent and water, which will cause them to drown.
  • Neem Oil: Neem oil and sprays containing potassium bicarbonate are somewhat effective, especially on roses. The adults ingest a chemical in the neem oil and pass it on in their eggs, and the resulting larvae die before they become adults. Neem can be harmful to fish and should be reapplied after rainstorms.
  • Use a Dropcloth: Put down a dropcloth and, in the early morning when they’re most active, shake them off and dump them into a bucket of soapy water.
  • Insecticides: If you wish to spray or dust with insecticides, speak to your local cooperative extension or garden center about approved insecticides in your area.
    • Or, try this safe homemade solution: Mix 1 teaspoon of liquid dishwashing detergent with 1 cup of vegetable oil and shake well; then add it to 1 quart of water. Add 1 cup of rubbing alcohol and shake vigorously to emulsify. Pour this mixture into a spray bottle and use it at ten-day intervals on pests. Homemade sprays can run more of a risk of damaging plant leaves, so be careful.
    • Apply sprays in the morning, never in full sun or at temperatures above 90ºF. If your plants start to wilt, rinse the leaves immediately with clean water.
  • Traps: Japanese beetle traps can be helpful in controlling large numbers of beetles, but they also might attract beetles from beyond your yard. Eugenol and geraniol, aromatic chemicals extracted from plants, are attractive to adult Japanese beetles as well as to other insects. Unfortunately, the traps do not effectively suppress adults and might even result in a higher localized population. If you want to try them, be sure to place traps far away from plants so that the beetles do not land on your favored plants on their way to the traps.
  • Fruit Cocktail: You can buy Japanese beetle traps of all sorts, but most are no more effective than a can of fruit cocktail. Open the can and let it sit in the sun for a week to ferment. Then place it on top of bricks or wood blocks in a light-colored pail, and fill the pail with water to just below the top of the can. Place the pail about 25 feet from the plants you want to protect. The beetles will head for the sweet bait, fall into the water, and drown. If rain dilutes the bait, start over. 
  • Geraniums: Japanese beetles are attracted to geraniums. They eat the blossoms, promptly get dizzy, fall down, and permit you to dispose of them conveniently with a dustpan and brush. Plant geraniums close to more valuable plants which you wish to save from the ravages of Japanese beetles. 
  • Japanese Beetles on Roses? Note that insecticides will not fully protect roses, which unfold too fast and are especially attractive to beetles. When beetles are most abundant on roses, nip the buds and spray the bushes to protect the leaves. When the beetles become scarce, let the bushes bloom again. Timeliness and thoroughness of application are very important. Begin treatment as soon as beetles appear, before damage is done. 

NOTE: Many dusts or sprays are highly toxic to honeybees. If application of these materials to plants is necessary during the bloom period, do not apply during hours when bees are visiting the flowers. If larger than yard and garden plantings are to be treated, you may need to contact nearby beekeepers in advance so that they can protect their colonies. 

japanese-beetle-identification-control.jpg
Photo Credit: Jeff Hahn, University of Minnesota. Sometimes the easiest way to get rid of Japanese beetles is to pick them off the plants before they do too much damage.

How to Prevent Japanese Beetles

Unfortunately, there is no magic potion to get rid of this pest. For general preventive maintenance, experts recommend keeping your landscape healthy. Remove diseased and poorly nourished trees as well as any prematurely ripening or diseased fruits, which can attract Japanese beetles. Try these tips:

  • Select plants that Japanese beetles will not be attracted to. See our list of the Best and Worst Plants for Japanese Beetles. Dispersing their favorite plants throughout the landscape, rather than grouping them together, can also help.
  • In the grub stage of late spring and fall (beetles have two life cycles per season), spray the lawn with 2 tablespoons of liquid dishwashing soap diluted in 1 gallon of water per 1,000 square feet. The grubs will surface and the birds will love you. Spray once each week until no more grubs surface.
  • You can introduce the fungal disease milky spore into your lawn to control the Japanese beetle larvae population. The larvae ingest the spores as they feed in the soil. The spore count must be up for two to three years for this method to be effective. Fortunately, the spores remain viable in the soil for years. This is an expensive treatment, as all the soil within five-eights of a mile needs to be treated for good control.
  • You can also drench sod with parasitic nematodes to control the larvae. The nematodes must be applied when the grubs are small and if the lawn is irrigated before and after application. Preparations containing the Heterorhabditis species seem to be most effective.
  • Companion planting can be a useful strategy in preventing pests. Try planting garlic, rue, or tansy near your affected plants to deter Japanese beetles. 
  • You can also attract native species of parasitic wasps (Tiphia vernalis or T. popilliavora) and flies to your garden, as they are predators of the beetles and can be beneficial insects. They will probably attack the larvae, but they are not very effective in reducing the overall beetle population. 

Plants Affected

Reader Comments

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Better than hand picking

I use a shop vac to vacuum up Japanese beetles off my plants. Adding pieces of PVC pipe as an extension to the tubing lets you reach up high. Try different sizes of vacuum attachments to get suction enough to grab beetles with little damage to the plant. It's very emotionally satisfying to pour bleach on several gallons of beetles at one time, die beetles!! :) Wonder how many beetles are in a gallon?

And if you do the tarp trick mentioned in the article, do it when it's chilly before dawn, as soon as they warm up they will start flying. Sweep them off the tarp and into a can often, so if it warms up a degree or so and they start flying, they don't get away.

For trees I use Bayer

For trees I use Bayer Advanced 12 Month Tree and Shrub Protect and Feed Concentrate works great but you need to put it on by the beginning of May. For roses I use Bayer Advanced Rose & Flower Care Plant Food For Shrubs Ornamentals every 6 weeks. Works very well. I need something for my raspberries. This year I am covering them with tomato cages and netting. I hope that works.

Beetle Battle

Ivctried everything against the beetles. I mean everything. There is not a plant or tree or shrub in my yard that they do not love. It's so discouraging to find them attacking everything all day as soon as my flowers start to mature. No one mentioned it, so I will. I used the buckets of soapy water for years. Now I find it easier, faster and more effective to just slip on the gardening gloves and and starting to smash them. I pull them off and crush them and drop them. Usually, I can pick 4 or 5 at a time. I know they are dead, and I don't have to use any tools or water or soap or powder or anything. Just grab them and crush them. I'm so sick of these things I use my bare hands when my gloves aren't with me.

Milky Spore

Use Milky spore. It's the only permanent solution! It works..but it might take two or three times.

I tried growing roses the

I tried growing roses the first time ever, and the JB's devoured them. Late August now, and they are finally mostly gone, its amazing.
I have read somewhere that if you use a blending container only for this purpose, put a large amount of dead beetles in, and liquify them (I know it's gross), spray your plants, and the smell of the dead ones will repel any more.
also how far is far enough from the garden to put the bait lures? Is 2-3 acres away enough?

Japanese beetles

I have also been bombarded by the beetles and have sprayed and used traps. My question is, do they end up in the traps before or after they have laid eggs? Or both?

what abou tthe eggs?

The answer is a little of both, JL.Many females will lay eggs near the traps, creating problems next year. Read the advice above as well as the comments below. There is a lot of beetle wisdom here!

Detergent method of killing

If I put the mixture of vinegar, sugar and liquid detergent in a small pail with handle, can I hang it on a shepherds hook or does it have to be on the ground?

Detergent Beetle Trap

Yes, you may hang the trap from a hook. The beetles are attracted to the smell, so it doesn’t really matter where the trap is, as long as it’s accessible.

Kill Japanese beetle

Use dawn dish soap, put 1 oz per gallon of water. Spray them . They will drop over dead.
This is the best way I find it out. Try it. It works.
Good luck.
Ron

Japanese Beetles. Grrrrrrr

I have been cutting our lawn about once a week due to all the rain we have had in SE Wi. One week ago my trues looked healthy, in fact we had a lawn service actually servicing our /trees and shrubs. On Tuesday, 7/25, I went out to mow the lawn and I noticed our River Birch had lost 2/3 of it's leaves. They have also attacked our American Larch, Goldrush Redwood, Crabapple Tree, Plum Tree, our Magic Spirea and starting some of the Maples. I am just SICKENED at the amount of damage they have done. So far they have left our Dakota Arborvitae and our Green and Gold Arborvitae alone. We have since called "said" lawn service to come out to re-spray again. Why has this not taken care of them? Will our trees recover? At what point is the decimation beyond the point of no return? We have a LOT of money in these trees/shrubs and the "service" has a guarantee. What do we do now?

japanese beetles

How do you pick the beetles off of a 50 foot tree. And how do you spray or kill the beetles 100feet in the air. I keep them out of my house only by using a electric bell in howell thing that makes a sound through the house and they don't come in but when I go outside they bite and the bite is a serious sore that I now have had on my skin more than 3 months. Nothing works to stop the itching, blisters that burn and run. One bite makes a sore 2 inches in diameter. All leaves are on the ground and the grass is being eaten everything in their path is dead.

Japanese beeltes

Japanese beetles are so bad in central Illinois they just move fron tree to tree eating every leaf and killing everything in their path. The bite from these bugs causes an infection on your skin that is painful and is hard to heal. It turns red, blisters, does not heal well. Leaves a large sore on the skin, itches and burns to touch, nothing stops the pain and blisters. The trees are dying everywhere from these beetles as they eat everything in sight. What will stop them, how do you kill them. Huge trees dying from town to town. What can be done?

Japanese beetles

I noticed we have Japanese beetles in our apple tree, the apples are falling and the leaves are getting eaten, what would you recommend ?

Japanese beetles and apple trees

Traps are not always effective for fruit crops because they attract the beetles from miles around and many females will lay eggs nearby, creating problems next year. To get rid of the beetles, there is a wide range of insecticides for the immediate control of beetles—from the broad-spectrum insecticides (eg., Sevin) to the organic options. See this page for examples: http://msue.anr.msu.edu/news/managing_japanese_beetles_in_fruit_crops but check with your state’s cooperative extension to see what’s permissible and advised where you live. In the future, to avoid this pest: 1. Reduce weeds. Apply an herbicide in the fall. 2. If you put down any sod between apple trees, remove grass and use a non-grass cover crop and restrict irrigation in areas near the tree(s) and use a drip system to reduce the habitat for these beetles.

I have effectively controlled them with

I have used a bag trap with pheromone attractant. But I cut the bottom off the bag, put a three inch pvc pipe going into a 55 gallon barrel and bag. It brings in a ton of beetles but they all come off my foliage and trees. It will fill up a couple of barrels in a season, but it saves my garden. I garden an acre of vegetables and fruit trees. I also use a kaolin clay called surroundDT from Johhny's Seeds. Totally non toxic.

When I put the modified bag trap out the beetles come in swarms, go into the trap, down the pipe, into the barrel, and they die in the barrel. I have a hole for the pvc pipe cut into the lid of the barrel. This method has worked for a few years

Thank you

Thank you! Excellent idea!!
I think I'll see if the guy who owns the pasture near me will let me put a barrel trap on his land, he just grazes cattle, no gardening, and it's away from the gardens the rest of us have, but close enough to lure them, perhaps.

Mountain Ash

The are devouring the tree, will they kill it?

Variation on Fruit Cocktail attractant for Japanese Beetles

A simpler and cheaper alternative to the Fruit Cocktail attractant is Apple Cider Vinegar, dishwashing detergent, and sugar. I use about a cup of vinegar, a spoonful of sugar, and a few drops of detergent in a large open can. The fruity vinegar and the sugar attract them and they drown in the soapy water. No waiting for fermentation and there's only one container.

Japanese Beetle

Does the vinegar mixture get mixed into the water? Or put the mixture into a can to sit in the water?

japanese bettles in our American Elm

How do you get rid of them out of a large tree. It is to tall to spray. They are stripping all the leaves. How long do they feed?

Japanese Beetles in Trees

If the beetles are up too high to reach with sprays, then there’s not much you can do this season, unfortunately. There are some insecticides, known as systemic insecticides, that can be applied to the soil and will be absorbed by the tree, but these may take up to two months to be effective, by which point this year’s Japanese beetle populations will be gone. Japanese beetles typically feed between mid-June and late August. (NOTE: Before you decide to use a systemic pesticide, you should look carefully at the possible side effects, such as its impact on important pollinators like bees!)

They are BAD this year-2017!

They have attacked my grape leaves, devoured my wisteria and my crape myrtle. And of course, roses! I have sprayed seven dust liquid and powder and they do not care!!! I have also used the dishwashing solution and nothing has kept them off my plants this year!
The Junebugs are also horrible this year. Well every bug really, because we have had such mild winters in the last few years.
Any other suggestions????

getting the best of beetles

You will find all of our best advice above, April. We also checked readers’ comments below and—well, once more with feeling—review the options:

Milky spore, a bacteria the kills the grub of the Japanese Beetle, and beneficial nematodes are a natural way of getting rid of grubs in the soil. Check your local garden center or do a quick search online to find out more about how to use them. Be aware that these treatments can take a year or two to be effective.

 

You could try diatomaceous earth. It is available in a food grade version and would be safe for your pets to ingest (even beneficial in killing fleas and other insects that bother pets). It is a powder (ground, fossilized phytoplankton) and you can purchase a small pump to dust it on your plants with. It is not a poison, but an irritant to the bugs. It works its way into their exoskeletons and kills them.

 

One reader used a spray bottle filled with hydrogen peroxide and sprayed the roses; the beetles dropped instantly.

 

You might want to make some fermentation traps out of plastic milk jugs (with top off) holding a cup or so each of water, sugar, and mashed fruit of some kind (e.g., banana), plus a packet of yeast. Put some of these in your plants and see if they can attract the beetles.

 

And another comment suggests that neem oil and sprays containing potassium bicarbonate are somewhat effective.

 

For complete freedom, you need eliminate them in the grub stage of late spring and fall (beetles have two life cycles per season). Spray the lawn with 2 tablespoons of liquid dishwashing soap diluted in 1 gallon of water per 1,000 square feet. The grubs will surface and the birds will love you. Spray once each week until no more grubs surface.

Japanese Beetles

The Japanese Beetles are attacking my huge Pin Oak Trees. I can't believe how quickly the trees have deteriorated in less than 2 weeks. I'm frantically trying to get something done. Two people in tree business said they have never seen them in Oaks until this year.

Japanese Beetle Control

After being invaded by Japanese Beetles last year, we are going to apply Milky Spore this spring. Can we also spray the grubs with soapy water the same year?

Japanese Beetles traps

Think twice before using these!! We had corn fields on three sides of our property last year!!! We had traps in two areas of our yard!! We own 2 acres. We started using grocery bags as we were filling bags full 2 x a day!! We have come to believe that the pheramones pull the beetles out of the corn fields!! At this point this year they have completely killed one of our best apple trees and one of the others has 20 of the dam things on single apples!! Our peach trees at this point are loosing their leaves!! So sad!!! I really believe we should have never used the bags bought in the stores as we lured them all to our land!!
VERY SAD!!!!

Japanese Beetles traps

Do NOT use those traps except everyone in your community uses them as well. I set up a trap and it was very effective. < 5 days, it caught over 1,000 of them, they were all coming from everyone's backyard.

Japanese Beetles

We live on a 2 acre lot among corn and soy bean farmers!! The last three years we have been infested with the nasty beetles!!!! They have almost killed one of our older Apple trees and are also beating up our peach trees!!! I don't know how much damage has been done to the corn. Our trees are to big to spray and we are lost!! When do you start spraying the ground with dish soap and water mixture!! Hate to loose anymore trees!!!!
Gayle McCandless
Burlington, Iowa

Japenese Beetles

We live in SW Ia, Approx. 20mi E of Omaha/Co. Bluffs metro on 5acre plot. 4yrs ago, we took several of these to the DNR booth @ State Fair, asking for a positive id & control strategies, telling the DNR "officer" we thought they were Japanese beetles, but weren't sure. We were informed, in no uncertain terms, that Japanese beetles, had never been seen, were not expected to be seen, & if we would "just wait it out", whatever they were would die ,& not seen again. HAS NOT been a good strategy! Last yr, when checking the ripeness of the fruit in our 12 tree orchard, (apples, pears, peaches, plums), we discovered any individual fruit approaching ripening\picking time was covered w\these abominations,& eaten down to the core in short order, (hrs, not days). I started looking for solutions in April this yr, thinking i had until Aug to develop a strategy. It appears I'm gonna be 6 wks too late. Last Monday, (06/26), We started seeing them float in our above ground pool, & by Tues evening, we were dumping 150-200 of these evil\nasty creatures out of the skimmer daily sinc., Tues, returning home from parades, about a 20mi jaunt, we ran into 4 swarms of them coming out of farm fields, (beans & corn on either side), 2 of the swarms were so thick we were forced to slow from 60mph to 30mph & took almost an hr to get "bug juice", & squashed parts off car & windshield. Our fruit trees are starting to show leave damage, but no fruit damage evident yet. (best crop we've seen, btw), still haven't seen a workable solution for this infestation, but would certainly try something, if anyone has had success saving their fruit, please post up.

RickH~~Ad Astra per Astra~~
ps have pics of lastyrs infestation\damage, but find no way to attatch

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