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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Combat Japanese Beetles

I have used milky spore for many of years & it has really reduced the number of J-beetles in the flower, vegetable gardens & lawn. I lost a good part of my lawn to these rascals, used milky spore after reseeding & have not had a recurrence of the J-beetle infestation.

Hope this helps, Good luck

Japanese Beetles

These horrible beetles love destroying the leaves on my red Japanese Maples. Since these trees are so picky about anything put on them or in their soil, I'm scared to spray them with anything. The beetles also decimate my heuchera and banana plants. I have my dogs in the yard (it's their yard after all :-) ) a lot and I don't want to apply anything toxic to them either. The milky spore bag at my local nursery says poisonous to pets in a warning on the bag as did the neem oil spray. I hand pick when I can, but I'm not always home and these beetles work fast! Any pet safe ideas? Will putting garlic cloves around my plants (not planted, just placed around) help? Thanks!!!!

Safe beetle deterents...?

The Editors's picture

All of our best ideas, including homemade solutions that should be pet safe (thinking dish water detergent spray) are listed above. For example, 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.

However, if you read through responses to similar questions below, you’ll see that hand picking is best.

Or you could install different plants. Adult Japanese beetles feed on nearly 300 different host plants. Yes, roses are the ultimate feast. Other favorites include: flowering cherry and crabapple, zinnias, canna, marigolds, crape myrtle, linden, Japanese maple, and birch. See this page for options that these beetles will not pester: http://www.almanac.com/content/japanese-beetles-best-and-worst-plants

Japanese Beetles

We have a blueberry farm in Georgia. Last year, along with the drought, our plants were ravaged by the Japanese beetles. We are trying the milky spore this year, but my understanding is that it can take a while to really have the full effect. The best quick, although temporary solution I have found is 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. Rather than trying to pick hundreds of the beetles off, I found this much easier. It is not a poison, but an irritant to the bugs. It works its way into their exoskeletons and kills them. You can do a quick search and find lots of information on it and where to buy.

Japanese beetles

Thank you for posting this. I have Diatomaceous earth and use it for ants. When is the best time to apply?

Japanese beetles and fruit crops /leaves and fruit

Hi ! I am excited to try de but want to avoid harming beneficial bees will they be harmed by de ? Do you only apply it at certain times ? Do you know a great source for the price
I have a huge garden etc and would nred A LOT

Source for Diatomaceous Earth

Check your local farm supply places, they sell it as animal feed additive. I paid 14.00 for a 50 pound bag.

Japanese beetles ridding them

If you got the time and patience, follow along. Get a small jar with an inch or two of gas in it, then go Beetle Hunting. After putting them in the gas, they will nose-dive to bottom of jar and on the way will break wind. Seriously, folks I tried this and it WORKS!

Use of gas on jap beetles

The use of gasoline to kill Japanese beetles is not only unsafe and irresponsible it is a VERY stupid thing to do. Use soapy water instead.

Beetles

I've used a 3# 'wide mouth' coffee canister filled with spent motor oil. Once they 'fall' into the wide mouth, game over! Or, you can hand pick the beetles and toss them in. I realize this is like holding an ocean wave back with your hands but, I say it is one less beetle to worry about. Someone wrote about using a spray for mosquitoes and that was attracting the Japanese Beetle. I've also tried the Bag-a-Bug approach but the local raccoon ripped the bottom open. If one were to get a wide mouth container, fill it with old motor oil, and insert a Bag-a-Bug bag leading the the wide mouth....it might just work!

Do Indian Summer raspberry plants need to be winterized? If so,

Do Indian Summer Raspberries need to be winterized? If so, how. I live in Southern NJ.

Winterizing raspberries

Hi there! You do need to winterize raspberries in your zone. Try this:
1
Continue watering the raspberries long after the plants have stopped producing fruit, and don't hold off on watering until the first frost. This extended watering prevents over-drying during the winter and also helps harden the plants and prepare them for the cold.
2
Remove any of the brown canes that produced fruit during the summer but leave the green canes alone. When pruning the canes, cut them down to the soil level.
3
Bury the remaining raspberry canes if these are new plants that haven't experienced winter yet, as these plants are extra-sensitive to winter's chills. Push the flexible canes down to the ground and bury them under a couple shovelfuls of dirt.
4
Erect a simple fence barrier around the raspberry bush, as raspberries attract rabbits and other pests during the winter who like to feed on the plant's stems. Use traditional 1/4-inch mesh wire, which you can buy at garden stores and nurseries. The fence should go 3 inches into the soil, to keep rabbits from digging under it, and stand 20 inches above the soil to keep rabbits from jumping over it.

Things You Will Need
Pruning shears
Garden spade
1/4-inch mesh wire

Some raspberry varieties have thorns, although most domestic varieties have had this tendency bred out of them. If your raspberry bush has thorns, wear gloves and a long-sleeved shirt to protect yourself when handling the plant.

beetles

I live in Maine and found beetles eating my chamomile; plus other plants. I was told they were Japanese Beetles, but they looked liked coffee beans; they did not have the green metallic. They are in the soil...many of them. Do you have any idea what type of beetle it is?
Thanks, Annie

False Japanese Beetles

The Editors's picture

They could be sandhill chafers, which strongly resemble Japanese beetles, but without seeing them, we can’t say for sure.

Japanese beetles

A type of milkweed plants were covered/infested
with these beetles this morning at Home Depot on Atlantic Boulevard this morning in Jacksonville, Florida. It was brought to the attention of the employees.

Japanese beetles

I just went out to deadhead some geraniums - they did not fare well in recent storms - and found several Japanese Beetles nibbling away. I am surprised since geraniums are not often targeted by insects. Any comment?

Japanese beatles

Thank you for the info.

Japanese beetles

Over several days, I have been hand-picking scores of Japanese beetles off my young trees and rose bushes and dropping them into a bucket of soapy dish water effectively killing them. My question is this: are these beetles coming solely from my property or are they coming from neighboring properties as well. If they are coming mostly from my property, based upon my kill rate, then my lawn must be loaded with them?? Yes or no

Japanese Beetles

The Editors's picture

Rest assured, you are not fighting the battle on your field alone. Adult Japanese beetles are highly mobile and can feed on plants several miles from where you spot them.

Japanese Beetles

I found a great solution for the Japanese Beetle last year! I was sick from seeing the beetles covering and devouring my rose bushes. I took a spray bottle filled with hydrogen peroxide and sprayed them....they dropped instantly on a plastic tarp and died on the spot. I didn't have a single beetle left on my bushes and the peroxide acted like a fertilizer to the bushes. The leaves all grew back and the plants were covered with hundreds of beautiful roses. Didn't look like it affected bees at all. I sprayed the plants when the bees were at there homes. Cheap and easy solution!
I'm going to try it on all my plants if I see those critters again this year. I'm thinking about trying a spray of a peroxide/water solution on my lawn also. I'll let you know how that does.

Peroxide to Rid Roses from Japanese Beetles

THANKYOU SO VERY MUCH FOR THIS WONDERFUL TIP! I AM GOING OUTSIDE TO TRY THIS ON ALL MY ROSE BUSHES AND HIBISCUS RIGHT NOW!! VERY MUCH APPRECIATED!! SINCERELY, NICOLE K.

japanese beatle

I wonder what strength (water:peroxide) ratio did you use? were plants affected?

Peroxide ratio

Said they sprayed the plants with 'peroxide'.. and was only considering a mixture for the lawn.
Cheers

Japanese Beetles this year

I always have Japanese Beetles and they always show up around the 4th of July. Their favorite plants in my garden are: Rose of Sharon,Rose Mallow, Annual hibiscus - ALL and ANY hibiscus plants, roses, Petunias, and Hakuro Nishiki- Japanese willow shrub. They will completely decimate Rose Mallow. This year the hibiscus are all slower to bloom, but the beetles came out. I found them eating the leaves, but not that many this year. Yesterday, I went around to pick them off and found only dead ones all over the Geraniums! I have never seen them dead before hanging on the plants, so I have assume the Geraniums are deadly for them. Get some Geraniums and put them out. maybe this will work for others as well. I am located in N IL.

Japanese Beetles and Geraniums

The Editors's picture

Yes, you are right! Geraniums can be deadly to Japanese beetles, and planting them can be a good method of control. Check out this page for more plants that Japanese beetles don’t like.

Geraniums toxic to pets

Be careful with geraniums around pets as they are poisonous to them (and young children if they'll eat them).

Japanese beetles

' Hand Pick'. By holding a paper plate under the beetle. Touch the beetle with a stick or finger, they will 'freeze' and fall onto the plate. Then fold plate and squeeze over the bug. The plate will hold many beetles. Very dead

japanese beetles

Is there a problem with using the lure traps sold at most garden centers that have the sex and food lure in them? I can't find any comments about it.
Are these not safe? please help!

Sticky Traps for Insect Pests

The Editors's picture

Yes, they are a very good, nontoxic tool for pest management.

However, traps cause the beetles to love your yard best.

After talking to a local chapter of the National Wildlife folk at a recent town faire, I stopped using the traps. The attractant in them basically makes all the beetles drop the larva in YOUR yard instead of your neighbor's. Sure enough, this year, I'm having much more trouble than ever before. You're better off using milky spore and nematodes.

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