Japanese Beetles

How to Get Rid of Japanese Beetles in the Garden

japanese-beetle-garden-pest-bug

Use these tips to get rid of Japanese beetles.

Crestock

Got iridescent green beetles feasting on your roses? Those would be Japanese beetles! Here are tips on how to identify and get rid of Japanese beetles.

What Are Japanese Beetles?

Japanese beetles (Popillia japonica) are small insects that carry a big threat. They do not discriminate when it comes to what types of plants they feed on, though they do have favorites (like roses). 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 to the United States in the early 1900s, the Japanese beetle was found only on the islands of Japan, isolated by water and kept in check by its natural predators. 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, and by 1920, eradication programs were dropped; the beetle proved to be too prolific and widespread. 

Identification

How to Identify Japanese Beetles

Japanese Beetles are ½ inch in length with metallic blue-green heads, copper-colored 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 underground for about 10 months, overwintering and growing in the soil.

They emerge from the soil as adult beetles and begin feeding the following 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.

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Photo Credit: Ohio State University. Japanese beetles cause leaves to appear skeletonized.

Signs of Japanese Beetle Damage

Japanese beetles feed on a wide variety of flowers and crops (the adult beetles attack more than 300 different kinds of plants), but in terms of garden plants, they are especially common on roses, as well as beans, grapes, and raspberries. Here’s what to look out for:

Skeletonized Leaves and Flowers

Japanese beetles can devour most of the foliage on favored plants, as well as the flowers. Look for leaves that are “skeletonized” (i.e., 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 the beetle by their appearance as well.) Japanese beetles are not usually far from damaged leaves, so inspect the plant thoroughly. Also keep an eye on the ground beneath the plant; the beetles may reflexively drop off the plant if disturbed.

Unhealthy, Brown Patches in Lawn

Japanese beetle grubs damage grass when overwintering in the soil, as they feast on the roots of lawn grasses and garden plants. This can cause brown patches of dead or dying grass to form in the lawn, which will pull up easily thanks to the weakened roots. 

Control and Prevention

How to Get Rid of Japanese Beetles

Good horticultural practices, including watering and fertilizing, will reduce the impact of 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 that begins in mid- to late May in the southern U.S. and in mid- to late June in the North. Row covers will keep the pests out, but they will keep pollinators out, too; be sure to remove them if your crops need to be pollinated.
  • Hand Pick: Unfortunately, the most effective way of getting rid of Japanese beetles is to hand pick them off of plants. 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 adult beetles ingest a chemical in the neem oil and pass it on in their eggs, and the resulting larvae die before they become adults. Note: Neem can be harmful to fish and other aquatic life, so don’t use it near lakes, rivers, and ponds. It must be reapplied after rain.
  • Use a Dropcloth: Put down a dropcloth and, in the early morning when the beetles are 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 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.
      Warning: Homemade sprays can run more of a risk of damaging plant leaves, so be careful and use sparingly. It’s always a good idea to first test a little bit of your spray on a small part of your plant, wait 24 hours to see if there are any adverse reactions, and—if not—proceed with spraying the rest of the plant.
    • 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.
  • Japanese Beetle 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 target plants so that the beetles do not land on your favored flowers and crops on their way to the traps.
    • Fruit Cocktail Trap: 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 from the natural chemicals in the geranium, fall off the plant, 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. 

For rose growers, see our Growing Guide for Roses for more tips on caring for roses!

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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:

  • Choose the Right Plants: 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.
  • Get Rid of Grubs: 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.
  • Milky Spore: You can introduce the fungal disease milky spore into your lawn to control the Japanese beetle larvae population. The grubs 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.
  • Beneficial Nematodes: 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.
  • Plant Strategically: Companion planting can be a useful strategy in preventing pests. Try planting garlic, rue, or tansy near your affected plants to deter Japanese beetles. 
  • Parasitic Wasps: 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. 

WARNING: Many dusts or sprays are highly toxic to honeybees, native bees, and other pollinators. If application of these materials to plants is necessary during the bloom period, do not apply during hours when bees are visiting the flowers (late morning through mid-day). If more than just a few yard and garden plantings are to be treated, you may need to contact nearby beekeepers in advance so that they can protect their colonies. 

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Reader Comments

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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

The Editors's picture

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

The Editors's picture

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

Japanese Beetles

I use seven liquid and spray my garden and fruit trees is the only way I could save my crops and fruits it will kill them all but you will need to spray again after a rain

japanese beetle fix

just found out the things were destroying my plum tree. I knew sevin dust worked to rid these from roses, so tried the liquid sevin and hit my tree for 3hrs coating it as well as possible and now have many, many dead beetles. also covered lawn with the sevin granular. feeling better and hopefully won't lose my plum tree.

how to get rid of japanese beetles on plants, trees,flowers

mix up a homemade mixture of 2 cups of ammonia , 1 cup lemon Joy liquid dishwashing ( yes it has to be joy others will not work , 7 capfulls of neem oil , 5 softgels of garlic oil broken ooen and squeezed into this, 1 teaspoon of baking soda . mix well shake well into a water dispenser sprayer ( for total yard ) . spray everything mixing with water in a ratio of 40% water to 60 % mixture . repeat this every three days , then twice a week , then only once a week , and continue throughout dummer . you will have a lush garden paradise !

Bag trap: Once in how do they die? How soon? Where to empty?

Hello,

I am trying a bag trap. Once the Japanese Beetles are in how do they die? How soon do they die? Will all of them be dead when I empty the bag? Where to empty?

I live on an acreage, with farm fields on three sides.

Sheri

Beetle bag trap.

Hi Sheri,
I've been battling with the J Beetles for 3 summers now. I tried the traps last year( yes they die in there).
I truly believe whatever is in those bags attracted more beetles. This year I tried nematodes, in a sprayer in
mid June, I think I was too late. I have 2.2 acres and can't afford to spray the whole area. The last few days we have literally pulled a few hundred and dropped them into mineral oil they die in a few seconds. It seems to be
the only solution thus far. As a rule I do not kill anything insects included, but these are devastating. Let me know if you find anything that works. Good luck. Nancy

Dispose idea: in farm field or yard (as nutrients?).

Nancy,

Thank-you.

Mineral oil, you say?

I am thinking of disposing of the dead bodies back onto my acreage ground, or the farm field next to me. I suppose they will enrich the soil.

When my bag was 3/4 full, the top layers of bugs were not dead. I have a kid's swimming pool, about 4' in diameter, I put about an inch of water in it and added some soap. I unzipped the bottom of the bag and let the whole lot fall into the pool. The remaining live ones, died there. Now I need to go find a pool skimming net!

Bag 'em

We've used the bag traps along with spraying our fruit trees once or twice for the last couple years. We just have a suburban lot. We empty the bag once or twice a week into an old frozen veggies bag and throw it in the garbage.
This year we put up the old trap but forgot to get a new bait. It caught a few and stopped working. Long story short our plum tree only has about 50% of its leaves and now they're working on the Apple trees and grape vines. Not to mention they've destroyed a lot of fruit. None of the neem oil at this stage or soapy spray did anything, only the bag traps work (not wanting to poison our fruit). So we may attract more bugs, well we already do because of the fruit trees. But I'm just fine with that; they can go into the bag to die also ;)

Rose Chafer Damage

chafers have eaten 90% of the linden tree leaves HOW do we save the Trees?

Accidental Japanese Beetle Attractant

While trying to reduce the number of annoying mosquitos in my backyard using Repel's Outdoor Camp Fogger, shorty after spraying it around my patio deck, we were swarmed by hundreds of Japanese Beetles. This wasn't just a fluke since it happened several times after using the fogger. Who would have thought a repellant would attract these beetles.

Japanese beetles

I have had massive beetle invasions for going on 6 years. I have had no luck. I start each day with a surgical glove on and a pitcher filled with water and Clorox. Why Clorox ? The fumes seem to over come the beetles so they do not fly away to the next branch, next plant, or at times down my shirt. I am talking thousands of beetles for weeks. They have driven the bees away. I used to have migrating humming birds but that has stopped I had 7-8 feeders that would be covered. The beetles love pussy willows,gold raspberries,clematis,June beauty berries,and strawberries. My grape vines were :one in 2 years. Why am I fighting a losing battle? A corn/bean field adjacent to my land. The farmer seems to be intent on fighting weeds not bugs. It's going to cost him big time as his first time spraying Round up it wiped out my pine tree, 4 arborvitae, my red delicious apples, and an 84 foot bed of strawberries. I am 66 years old and I've prayed each year for relief each Spring. After reading this article I know that won't happen but I'm going to try planting some of the plants suggested .

Japanese beatles

Instead of picking Beatles off plants place plastic cup with soapy water directly under beatle then just touch beatle, their inclination is to fall off plant and fly away , instead they fall into cup.

Soap Solution and dying time

Hello,

When you use the method of soapy water in a cup, what ratio of water to soap do you use? How long do you leave them in the solution? How do you dispose of them?

Sheri

Killing Japanese beetles in soapy water

Hi Sheri,
There's no magic formula. I literally just squirt some dish soap into a jar and then fill it 3/4 of the way to the top with water. You want enough that you can see it's a little soapy, but nothing crazy. The exact amount, brand, etc., don't seem to matter.
You knock them into the jar (or they fall in) and they try to swim around a bit. They usually stop fighting it within a couple of minutes, and then they are goners. I tend to let the jar keep filling up in hopes that the ones that get away are at least haunted by the bodies of their comrades. (This is warfare.)
When I do decide to empty it, I use the lid to create just a little opening to pour the soapy water down the drain. Then, I can dump the wet bodies into the trash, rinse the jar, and be ready to go again. If you're super grossed out, you could toss the whole sealed jar.
Last weekend was the worst here for beetles, so I was getting 12-20 from a single bush every hour that I went to check it. I just kept knocking them all into the same jar.
Hope that helps,
Julie

Japanese Beetles

I have fought these critters for years because I grow roses in my yard. I make the rounds of my rose bushes three to four times a day and spray the bugs with insecticidal soap. It kills them within seconds and is not harmful to any of the good bugs. Today, for instance--I count--I killed over 120. Just spray ' em.

Preferred plants

Perhaps because they are taller, the cherry tree leaves are being selected over the roses. (SE Virginia)

Getting rid of Japanese beetles

Could you give more details about what insecticidal soap spray you use. Is it something you mix? Where do you get the particular kind of insecticidal soap you're referring to?
Thanks,
Paul

Japanese beetles

Is there a certain kind of insecticidal soap you buy for the beetles that you spray on them I have over 23 rose bushes thank you

Japanese Beetles

I was told (not sure who) that Japanese Beetles were beneficial to the garden as they fed on aphids on the rose bushes....I have been reading in this forum where they are pests...What is correct ?

Japanese Beetle Pests

The Editors's picture

Japanese beetles are indeed pests. They feed on leaves and flowers (rose bushes are a favorite), but do not feed on other insects, such as aphids. Ladybugs (also called Asian lady beetles), on the other hand, are voracious aphid-eaters and are a great help in the garden. Get rid of the Japanese beetles, but keep the ladybugs!

Asian beetles - lady bugs

There is a difference between Asian lady beetles and lady bugs. Both eat aphids but lady bugs are harmless and stay outside. Asian beetles get into the house in the tiniest of cracks. Any farmer can tell you their house might be sealed but they still fight Asian beetles all year round. They fly around the rooms, they die and litter the floors, they bite, they stink, and they leave a stain behind sometimes. No pesticide seems to deter them. Even bug bombs can't get rid of them. I have seen them come in swarms out of the bean fields during harvest season. No, they are not the same as harmless lady bugs!

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