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.

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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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After treating my apple trees

After treating my apple trees for Japanese Beetles, do I need to pick off the eaten leaves from my trees? Or just leave them? I have searched and searched for the answer to this on many sites, please help.

Removing Damaged Leaves

The Editors's picture

Yes, it is a good idea to pick off the eaten leaves if you are able to do so. Beetle-damaged leaves emit certain odors that could attract other beetles, so it is best to remove them.

Japanese beetles

Found another favorite food of these horrific beetles got them by the thousands apparently the only way to rid yourself of them is to hand pick them . Wish there was another way to get them off my mulberry trees . Tried seven dust irritated them killed a few but not many . Tried an organic spray of dush soap vege oil and garlic but nearly killed my trees . And the beetles wouldnt stop . Now trying hand picking them off have a jar nearly full and there still coming . If anyone has any other ideas that would be great .

Hi Ken,

The Editors's picture

Hi Ken,

Hand picking is the best way to get rid of these beetles. We have added a few more ways to get rid of them at the top of this page, nematodes being one.

I use a wet/dry vac to suck

I use a wet/dry vac to suck them off my roses, doesn't bother the roses much and I can catch 20 at a time just putting it down over the rose bloom then pulling back off. After vacuuming for about 20-30 minutes I seal it up well and leave it in the sun, then I feed them to my chickens. Repeat daily for best result and happiest chickens. :)

grubworm nightmare

Buckeye, az is where we're located. I have found out i pretty much have an infestation of grubworms. off of just about 98% of what i produce homesteading is how i manage to survive i plant all food productive plants melons peas strawberries cucumbers carrots basically anything i can get to grow that we can eat with nearly no financial budget. So i hav to be very careful when & what i do to my plants doesnt help im fairly beginner gardener. I've been tilling up grounds sifting out & squishing as many as i find also been tearing out all grass to jus bare grounds within 6ft radius of veggies areas

So im gonna try ur jug trap 4 adult beetles and soapy water spray but im really nervous my plants grow 100% off earth & water mainly cuz i cant afford any plant supplements. I know theres MANY different kinds of liquid dishsoap with different smells and cleaning power agents like Dawn, ajax some say triple action cuts grease, and other things.

I dont want to pick one that i shouldnt use so Which one would u recommend to use or is there anything in there ingredients that i should look to avoid when choosing the liquid dish washing soap? And is that liquid dishwashing soap for hand washing dishes or liquid dish washing soap for dishwashers?

Use dishwashing liquid like

The Editors's picture

Use dishwashing liquid like Ivory or Dawn. Don’t use dish washing liquids containing bleach or degreaser.

Green Beetles coming out of the ground in Nov. strange or not

I have these green beetles coming out of the ground in Nov. Is this strange? or Not. I have never seen this before. Does anyone know if this is the same type of beetle or if it is just this year's weather? Thanks to any one who can answer my question.

Beetlemania

The Editors's picture

Hi, La-shell: Without knowing where you are and more about what the beetles look like, it is hard to say what these are – but they are probably not Japanese beetles. Perhaps a tiger beetle of some sort. Thanks for asking!

I don't believe I've seen

I don't believe I've seen these, but if chickens will eat them, that may be why.

My chickens Love them! I

My chickens Love them! I knock them off my plants, into a cup. If you keep shaking the cup they can't fly out. When I dump out the cup the chickens gobble them up in an instant.

If I spray my corn in my

If I spray my corn in my garden with soapy water will it keep the japeneese beetles off them?

Spraying the corn with a soap

The Editors's picture

Spraying the corn with a soap spray is not going to hurt the plants and may help to keep the beetles away. Neem oil and sprays containing potassium bicarbonate are also somewhat effective. You can find these at garden centers.

Right now in blessed because

Right now in blessed because the beetles are only eating the weeds in my Garden. Darnedest thing I have seen. Problem is what are they going to target next. Looks like the may have stripped a pepper plant also.

I have found a few Japanese

I have found a few Japanese beetles on our cucumber, pumpkin, and zucchini leaves. We have marigolds planted around the garden as we heard this may help. I believe it is, as the marigold plants in the area have been chewed up like crazy. We will plant more. I have been walking through the garden every morning and picking them off and dropping them in soapy water as suggested. My question is can we somehow apply this to the leaves or area safely to help deter them? I've read different thoughts on this. This is our first year gardening, as a one income family with three kids. We need to make this work, any advice is much appreciated.

Also on our basil! Thanks

Also on our basil! Thanks for any advice!

Spraying the plants with a

The Editors's picture

Spraying the plants with a soap spray is not going to hurt the plants and may help to keep the beetles away. Neem oil and sprays containing potassium bicarbonate are also somewhat effective. You can find these at garden centers.

Can I use vanilla extract.on

Can I use vanilla extract.on corn or what can I use on corn to keep bettles away

Hi, Angie: Please see the

The Editors's picture

Hi, Angie: Please see the tips above regarding how to deal with Japanese beetles. Unfortunately, it is very hard to keep them away from corn once they have found it, so the trick is to get them off it or lure them away from it to begin with. One thing not mentioned above is 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 corn rows and see if they can attract the beetles. Good luck!

Help these beetles are

Help these beetles are killing my peach tree. I've tried several things from the store (seven dust and Ortha) and they did not work. I prefer something natural. Can you help me?

There are traps that you can

The Editors's picture

There are traps that you can use and neem oil and sprays containing potassium bicarbonate are somewhat effective. See above for other methods to get rid of the beetles.

The brown beetles that come

The brown beetles that come out at night might be June Bugs or Junebugs....I am not sure of the official name. They will decimate a basil plant in just a couple of days here in NC. They burrow in the ground below the plant during the day. I keep all of my basil plants in pots. The way I get rid of the beetles is to water the plant during the day which causes the beetles to come out of the ground...floating in the water. I grab them and smooth them between my fingers. I have not found a natural/organic spray to kill them. The good thing is they show up roughly at the beginning of June and go away roughly as the month of June ends so I don't have to fight them all summer. I'm going to try the nematodes this year. I hope they work.

The beetles u are referring

The beetles u are referring to are actually a reddish brown color and they're called asiactic garden beetles. They are nocturnal. They go under the dirt and eat the plant roots during the day then come out right after dark and eat plants. I have lots of them here at my house...they've been eating all my pepper plants. I found these cocroach traps that are little cardboard boxed with glue inside...so I opened them up and laid them flat under my pepper plants and it seems to be working cuz there's more and more on the traps every morning

My knockout roses are

My knockout roses are beginning to bud but a lot of the leaves at the top of the bushes are curling and turning brown. I can't see anything on them.I hope you can help.

Hi, Kathryn: Start by going

The Editors's picture

Hi, Kathryn: Start by going to "Gardening" above, then "Flower Growing Guides," then "Roses," where you'll find a number of possible pests/diseases. This could be a fungus of some sort, but more likely the plants are just "angry" because of their soil conditions. Make sure they are not being burned by too much fertilizer in the soil. Knockouts are fairly robust, but they are also "Goldilocks" in some respects: They need not too much nutrients/water/sun and not too little, but just the right amount. Make sure your roses are watered only down to about the 3 inch level in the morning; lightly spray the top leaves at night. Do research on some of the other possibilities on our Roses page. You should be able to solve this by online research here and elsewhere, but if you want something permanent to have, check out our Store for a downloadable 13-page digital Roses guide for 99 cents. Good luck!

Japanese beetles are all over

Japanese beetles are all over my gardens, flowering plants, grape vines, potato plants leaves, even roses. Impossible to hand pick them all, treatments wont work if surrounding neighbors don't do something about them, they are flyers. Looking for a localized treatment.

Try some Milky Spore. It's a

Try some Milky Spore. It's a bacteria the kills the grub of the Japanese Beetle. It is not harmful to pets, kids, fish, ponds or ground water supplies.

Milky spore toxic to pets

The milky spore bag at my local nursery says it's toxic to pets. Be careful if you have pets in your yard at all as milky spore stays for years too.

Found a gold colored beetle

Found a gold colored beetle with small white markings like triangles on it
burying itself in the dirt...It hid from me when I saw it !! It was not a Japanese beetle and havent found any that look like it in photo i/d's

I have a neighbor who was

I have a neighbor who was prosecuted by the EPA and fined $5,000 for killing Japanese beetles with Malathion,

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