What Kills Japanese Beetles? Powerful Tactics to Eradicate the Pest

Japanese beetle infestation is the most common phenomenon in any garden. The degree of infestation can increase rapidly if not appropriately treated. There are several methods of eradicating the Japanese beetle from a tree or even from a selected area. But not every method applies to every gardener.


There are some effective chemical insecticides but with some critical limitations. This article will discuss all Japanese beetle control methods, including chemical, biological and traditional controlling processes.

Does Sevin Dust Kill Japanese Beetles?


Sevin, a widely used insecticide, is applied to eliminate many insects from lawns and gardens. The active ingredient of Sevin is naphthyl methylcarbamate, AKA carbaryl. It is a non-systemic insecticide that won’t penetrate in plant leaves and will remain on the surface. When insects crawl or bite any leaf, the toxin will activate and denature the central nervous system.    

Now, you may ask, can Sevin kill Japanese beetles?

Yes, Sevin kills Japanese beetles by destroying their central nervous system. It is a neurotoxin and takes lesser time than other chemical insecticides to kill Japanese beetles.

An interesting fact is that Sevin can hamper beneficial pollinator insects like honeybees. So, if you want to save pollinating insects and kill Japanese beetle simultaneously, Sevin is not a good choice!  

Does Malathion Kill Japanese Beetles?

Yes, malathion kills Japanese beetles and many other harmful insects. Malathion is a potent neurotoxin that activates inside the insect’s nervous system and inhibits crucial enzymes to function properly, leading to beetle deaths.

In the Japanese beetle central nervous system, acetylcholinesterase (AChE) plays a pivotal role in passing nerve signals to the central nervous system. Simply, this enzyme keeps the beetle brain ganglia functional.


Japanese beetle has two antennae on its head. These antennas act as chemical receptors. When you apply malathion, the beetles’ receptors receive it via chemical nodes. Then, it will bind to the acetylcholinesterase (AChE) at nerve nodes, thus denaturing acetylcholine (ACh). When acetylcholine (ACh) is denatured, the Japanese beetle can’t move, leading to death.   

The perfect time to use malathion is near harvest time. It is wise to spray malathion every 7-12 days, as it has a shorter active period.

57% malathion is the perfect blend to kill Japanese beetle.

Moreover, malathion kills a wide range of insects. So, you should take precautions before using it. I would suggest using it at dusk, as most pollinators, pets, and useful insects will be inside or inactive.

Does Soapy Water Kill Japanese Beetles?

Yes, soapy water kills Japanese beetle, but it has some limitations. You can’t spray soapy water on the infected tree. Applying soapy water is lengthy, and there is no guarantee of 100% elimination of Japanese beetle.

The process of using soapy water is simple but laborious. You need to make a bucket full of soapy water. Then, just shake the infected area or the whole tree and let the Japanese beetle fall into the bucket. Then the pests will die because of cell lysis.

The best time to apply the soapy water method is early morning. At this time of the day, Japanese beetles are less active and sluggish; their grip is also very weak during this period. So, if you shake the tree well, you may have a good chance of having 90% Japanese beetle in your soapy water-filled bucket.  

Will Diatomaceous Earth Kill Japanese Beetles?


Diatomaceous Earth is a natural killer of the Japanese beetle. It can kill beetles efficiently and has a longer span of chemical activity. Most importantly, the “Food Grade” version of Diatomaceous Earth is environment-friendly and safe for pollinators, pets and children.

Diatomaceous Earth’s composition can vary depending on its intended use or targeted organism. Mainly, it is 85-95% silica, 2-4% alumina and 0.5-2% iron oxide. The interesting fact is that none of these chemicals is known as toxins. Then, you may wonder how Diatomaceous Earth works to kill Japanese beetle.

Diatomaceous Earth works on insects that have exoskeletons. Japanese beetle has exoskeletons that protect the softer skeleton-less inner organs. Diatomaceous Earth works on Japanese beetle by lysing the exoskeleton. It causes the beetle to dry out, and death is caused by absorbing fats from the cuticle of the beetle’s exoskeleton.

Most importantly, Diatomaceous Earth does not need to be consumed to kill an insect like the Japanese beetle. If a beetle crawled over the Diatomaceous Earth, it would face death after a few minutes.  

The way of applying Diatomaceous Earth to kill Japanese beetle is straightforward. Just spread and sprinkle Diatomaceous Earth over the garden’s ground and even onto the plant. You need to apply it in dry weather, as wet or liquified Diatomaceous Earth doesn’t work properly.

Lastly, I would suggest using food grade Diatomaceous Earth to kill the Japanese beetle. Also, don’t use it excessively to kill pests. Only re-use it after every rain, gently and at an optimum level.

Do Geraniums Kill Japanese Beetles?


Undoubtedly, geraniums is a beautiful plant with multiple medicinal and herbal properties. Scientists also claim that it has antibiotic activity. There is also a report that prevents the growth of endodontic enterococcal bacteria. Apart from bacteria, some insects also don’t like Geraniums.

A study by D. W. Held and D. A. Potter published in Environmental Entomology Journal confirmed that Japanese beetles become paralyzed and die due to the consumption of flowers of zonal geranium. Reference is Here.

Japanese beetles hate the smell of raw geranium, even dried geranium flower powder.

But, if you are a regular gardener facing a Japanese beetle infestation recently and looking for an urgent solution, planting geraniums is useless to you. But, you can collect the flowers of zonal geranium from the market or fellow gardeners and use it to reduce the Japanese beetle population. Still, scientists are looking for an effective method to use geranium to control devastating Japanese beetle.

Does Bt Kill Japanese Beetles?


Bt is very effective against adult and grub forms of Japanese beetles. Sometimes, the Bt strain is different for controlling adults and grub from the Japanese beetle. You can always check with your nearest agriculture extension officer regarding the availability of Bt strain, as it is not readily available in all shops.

Bt is a target-specific microbial insecticide. You can use it as a normal insecticide usually used in the soil. One important thing to note here is that the target insect must ingest it to get activated. It is a stomach poison, only activated in the insect gut.

So, you can use it as a normal insecticide, as it has a huge advantage over chemical insecticides. Bt only targets selected organisms, so pollinators like honeybees are not hampered by it.

I suggest using the Bacillus thuringiensis galleriae strain, which is widely effective against adult and grub Japanese beetles. You might not find it in normal garden stores; check out special online stores or your local extension agent for more info.

Does Insecticidal Soap Kill Japanese Beetles?


Insecticidal soap kills Japanese beetle when applied directly to the body of it. It kills Japanese beetle by suffocation, removing the exoskeleton’s waxes, resulting in dehydration and death.

The active ingredient of insecticidal soap is potassium-based salts of fatty acids. It is manufactured when complex alkali is proportionately mixed with fatty acids in natural resources like coconut oil, olive oil, and castor oil.

But, the commercial composition of insecticidal soap is a bit different. Some manufacturers removed the weakness of insecticidal soap and added pyrethrin, which offers rapid killing and a bit of residual effect. Insecticidal soap alone lacks residual effects.

The application process for using insecticidal soap is very simple. If you buy a premixed insecticidal soap then you can have the luxury of using it as it is. But, if you purchase mild liquid soap, mix 1 tablespoon into 1 liter of water.

Spray Insecticidal soap directly on the Japanese beetle. As it has no residual effect, the beetle that is not directly sprayed won’t be harmed. But, surrounding beetles will be stunned by the effect of the soap.

The best time to use the insecticidal soap is in the morning or dusk when Japanese beetles are very inactive and other beneficial insects are not around.  

Does Permethrin Kill Japanese Beetles


Permethrin is a widely known insecticide known for controlling a wide range of pests. It belongs to the pyrethroids family, a synthetic chemical that acts as a natural extract of chrysanthemum flowers.

Permethrin kills Japanese beetles. It should be used in the highest concentration if used in liquid form. Also, you can use it in dust form.

I recommend using permethrin dust overspray. The powder acts quickly and repels adult Japanese beetles for up to a week. Permethrin powder doesn’t harm the plant and is also safe for pets and humans after getting dried.

Remember, pets and children should not be there when applying permethrin in the garden. They can return after the powder spray is dried.

Permethrin has a residual effect. The average half-life of this chemical in the soil is about 39.5 days.

Permethrin works on the Japanese beetle by over-exciting the nervous system, eventually leading to the beetle’s death.

Does Triazicide Kill Japanese Beetles?


Triazicide kills both adults and larvae of the Japanese beetle with its active ingredient of Gamma-cyhalothrin 0.08%. One bottle of commercial triazicide kills approximately covers 2400 square feet areas.

The application process is pretty simple, hang it to the end of the garden hose to attain even spray.

Triazicide is a powerful chemical insecticide. It kills a wide range of pests, so it is not a good choice if you are just targeting Japanese beetles and don’t want to harm beneficial insects in your garden. Other safe methods exist to remove Japanese beetles from outdoor and indoor spaces.

Does Bifenthrin Kill Japanese Beetles?


Bifenthrin is a foliar insecticidal spray used to eliminate Japanese beetle from different types of trees. Use Bifenthrin 7.9% to get the best result on Japanese beetles. It has 2 to 3 pounds of active ingredient per gallon. You can also use Bifen I/T to attain faster results.

Bifen I/T has a better performance than permethrin oven Japanese beetle. Permethrin breaks down quicker under sunlight and loses its potency, but Bifen I/T remain the same for hours. Similarly, the activity span of Bifen I/T is 30 days, and permethrin is about two weeks, which means you need to re-apply it after two weeks.

The best time to apply it is at dawn. Just, mix 5 to 10 ml of bifenthrin in one liter of water, and mix it well. Then, spray it on the affected plant. When Japanese beetle walks over the spray after it has been dried, it will face a nervous breakdown and dies.

Does Dish Soap Kill Japanese Beetles

Dish soap kills Japanese beetle and is one of the most helpful pest control systems without harsh chemicals.

Does Dish Soap Kill Japanese Beetles

Just mix one tablespoon of dish soap with one quart of water. Mix the solution well into a bucket and then load the solution into a spray bottle. Now, spray the solution directly on the Japanese beetle. The best time for application is at dawn.

After the application, you can collect dead Japanese beetles in a water-filled bucket or let them fall on the soil surface. I would suggest collecting them in a soapy water-filled bucket.

Does Dawn Dish Soap Kill Japanese Beetles

Does Dawn Dish Soap Kill Japanese Beetles

Image collected from betterbe

Dawn dish soap can kill adults and larvae of Japanese beetles. Eliminating Japanese beetles from the tree with Dawn dish soap is very simple. Mix one tablespoon of Dawn dish soap into one quart of water and mix well. Take the mixture into a sprayer bottle and directly spray on the beetles

Does Neem Oil Work On Japanese Beetles


Neem oil is a natural insecticide. It is made via cold press technology in the commercial extraction process. There are DIY processes by which you can also extract neem oil at your home.

Neem is the most potent plant-based insecticide that immensely affects many pests. The active ingredient of neem oil is azadirachtin. It has proven evidence of downregulating growth and reproduction of Japanese beetle.

Neem oil kills Japanese beetle but not instantly. Azadirachtin interacts with the hormonal system of the insects and destroys the appetite of insects, thus leading to death.

Neem oil and its active ingredient act as an insect growth regulator. The oil interferes mating of adult Japanese beetle, which struggle to lay eggs. Grubs also face hurdles to reaching the adult stage.

Now, you may wonder if neem oil can kill adult Japanese beetles.

No, adult Japanese beetle won’t be killed by neem oil. It only reduces or eliminates adult Japanese beetle reproduction capacity, destroys the potency of the beetle’s egg and hinders grub growth.  

The application process of neem oil on infected plants is simple. Spray commercially available neem oil on the infected plant so Japanese beetles can ingest it and become impotent. It’s important to note that you must spray neem oil the first moment you notice Japanese beetle infestation in your garden.

As you already know, neem oil is not a toxin. Scientists call neem oil an antifeedant, which is very specific to the pest. That’s why neem oil works perfectly on Japanese beetle. Moreover, the neem oil has a garlicky smell which keeps away insects from sprayed areas.

Making neem oil solution is easy. Take one gallon of water and mix four tablespoons of neem oil and one teaspoon of dish soap into a drum. Then, mix it properly, take it into a tank sprayer, and spray it into the infected plant.

Does Pyrethrin Kill Japanese Beetles

Pyrethrin Kill Japanese Beetles

The pyrethrin-based insecticide kills Japanese beetles. It is naturally found in chrysanthemums. So, if you don’t want to use artificially synthesized pyrethrin, then you can plant pyrethrin around your house to get rid of Japanese beetles.

This synthetic insecticide pyrethroids were made to replicate the insect-repelling features of pyrethrins.

As I have discussed earlier, pyrethrin breaks down faster under sunlight, which has benefits and one drawback. The advantage is that it is not harmful to humans as it persists on the plant for a shorter period. And the drawback is its lower persistence made it easier for grub to escape from the treatment. Remember, this insecticide is highly toxic to bees and other useful pollinators.

Does Vinegar Kill Japanese Beetles

Vinegar is acetic acid, a very mild organic acid used in different functions. There are some reports about using vinegar as a potential pest-controlling agent. Vinegar can kill a wide range of insects, but some limiting factors exist.

Vinegar treatment can only be done on alone insect or insect population. For example, if you want to control grubs and adult soil-borne insects, vinegar can be an option (not a smart choice), but you can spray it on the tree or leaves to control plant-borne insects.

Applying vinegar on trees infested with Japanese beetle will kill them all, and your plant will also die. The stoma of the leaves soaks vinegar and stops the photosynthesis process, eventually leading to the crowning of the leaves. Dead leaves mean dead trees, right?

You should not use vinegar to control any garden pests, it can only kill weeds.

How to Kill Japanese Beetles Without Harming Bees

Bees are vital garden insects known as prime pollinators. When we use insecticide to kill pests, bees become the unwanted target if we don’t choose the insecticide wisely.

If you want to save pollinators like bees from insecticide, then you should choose the traditional method of killing Japanese beetles.

The safest method to kill Japanese beetle without harming bees is to handpick the pest from the infected trees. You can simply spray soapy water on the infected tree at dawn, then the insects will be immobilized and then shake the tree or handpick the beetles.   

If you are not using a broad spectre insecticide, then there is no risk of harming bees or other pollinators.

Another biological based control can be done with Bt insecticide. Bt is very specific to Japanese beetle and won’t harm helpful pollinators like bees.


There are several methods of killing the Japanese beetle. The method you should choose must be based on the type of plant infected, the degree of the infestation, considering surrounding insects, Pollinators facts and effectiveness. I always prefer non-chemical-based methods, although the traditional methods are tedious. The advantage of chemical insecticides is removing the mass pest population in a shorter period.

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