Of all the different garden pests that can destroy your plants, Japanese beetles are some of the most destructive. These beetles will eat any type of foliage, and they multiply extremely quickly, making them very difficult to get rid of. Still, if you’re wondering how to get rid of Japanese beetles, you can use both natural substances (like diatomaceous earth, neem oil, etc.) and pesticides (Bonide Pyrethrin, Delta Dust, etc.) to exterminate them. In this article, I’ll explain what attracts these beetles, how to prevent an infestation, and the best products and methods to control these common yard pests.
If trying to exterminate Japanese beetles on your own becomes too challenging, I recommend Orkin, Terminix, and Aptive. These exterminators use traps, baits, and other chemically treated solutions that are often more effective than standard DIY methods. Get a free quote from some of the best pest control companies below.
History of the Japanese Beetle
Japanese beetles first came to the United States in the early twentieth century from Japan, and their numbers began to explode after the Environmental Protection Agency (EPA) banned DDT in 1972. Since then, each spring and summer, this green, blue, and copper-colored insect has devoured plants, flowers, crops, and shrubbery across the Eastern United States.
Getting rid of Japanese beetles can be difficult because this pest is an invasive species that multiplies rapidly and spreads quickly in the warmer months. However, with the right products and approach, it’s possible to control Japanese beetles each year.
What Attracts Japanese Beetles to Your Yard?
Most insects come into your yard in search of food, and Japanese beetles are no different. They eat virtually any type of vegetation, so your home garden is a smorgasbord for these hungry bugs. They’re especially fond of fruit trees, rose bushes, and other garden plants. Japanese beetles spend most of their life cycle underground, eating grass roots and other types of plant roots, but once they come up to the surface, they go on the hunt for foliage.
Japanese Beetle Life Cycle
According to the Animal and Plant Health Inspection Service (APHIS), Japanese beetles start as larvae underground for about 10 months and then emerge as adults in the late spring. Once they emerge, an adult lives for roughly two months and consumes massive amounts of foliage in this small span of time.
The entire life cycle takes about one year. One female Japanese beetle can lay eggs for upwards of 40 to 60 beetles per lifetime, so these bugs multiply extremely quickly.
These pests prefer warm and moist environments, so the Eastern and Southeastern United States is the largest region for Japanese beetle activity. The insects will swarm around a region and settle in places that offer plenty of plants and shrubbery for feeding. With such a large flavor palette, virtually any kind of plant is on the menu for these pests.
How To Identify Japanese Beetles
Adult Japanese beetles are oval-shaped and about a half-inch in length. The outer wing shell is copper-colored, and the head typically looks metallic green or blue from a distance. Japanese beetles also have six to eight patches of white hair clusters on the rim of their abdomens. It isn’t hard to identify these beetles, and most of them will feed on plants out in the open with no fear.
Another way to identify this pest is to check affected plants for Japanese beetle damage (like leaf shredding). Adult beetles prefer to feed on the outer parts of foliage instead of the roots, which makes leaves appear skeletonized. These beetles chew away the exterior of the leaf, leaving a veiny, hollow look to the plant.
It’s not just adults that you have to worry about. Japanese beetle grubs will feed off the roots of plants underground before becoming adults in the spring. That’s why Japanese beetle pest control needs to target both adults and the grubs.
Can Japanese Beetles Get Inside Your Home?
Japanese beetles need soil to reproduce, but if outdoor populations are crowded in the garden, they may fly indoors to feed on the houseplants in your home. If you don’t have any indoor plants for them to feed on, the beetles won’t stick around, so they’re not known for being common house bugs. However, if you see any beetles crawling on the surfaces of your home, just put on a pair of gloves and squash them.
Are Japanese Beetles Good for the Environment?
According to the United States Department of Agriculture (USDA), Japanese beetles aren’t good for the environment, and they pose a serious threat to agriculture across the country. Since they eat over 300 different types of plants, they’re not beneficial insects, and they’re destructive both as grubs and as fully-grown adult beetles.
What Natural Remedies Will Get Rid of Japanese Beetles?
If you’re hesitant to put pesticides on your lawn, there are usually some natural alternatives to try before you jump to using insecticides. With Japanese beetles, there are a few natural control methods you can choose from.
Diatomaceous Earth
Diatomaceous Earth is one of the best methods to use for treating a wide area in your yard. According to the National Pesticide Information Center, DE powder is made from tiny, crystal-like fossils called diatoms. These fossilized shells are made of silica that has microscopic, razor-sharp edges that can rip the waxy outer shell of insects.
Insects can’t develop resistance to the sharp edges of the shells, so diatomaceous earth is extremely effective. DE powder also acts as a drying agent when insects walk through it. Once the powder attaches to a beetle’s body, the insect dies from dehydration in as little as 24 hours.
Diatomaceous Earth doesn’t kill plants, and the product won’t deactivate once it is wet. However, strong thunderstorms and heavy downpours can wash the powder away.
To apply DE powder, put on a pair of latex gloves to prevent your skin from drying, and spread the powder on all plants and shrubbery. Use a dust applicator to avoid clumping so the beetles won’t just fly around it.
Food-grade Diatomaceous Earth is generally safe around pets or children. But it is always a good idea to check their activity when outside near the powder. DE powder is evergreen as a residual — even if the product gets wet. It will work again once it dries out as long as it isn’t washed away.
Neem Oil
Neem oil comes from the Neem tree, which is local to Asia, and the oil extracted from the tree is one of nature’s naturally occurring pesticides. It is a yellowish-brown color with a slightly bitter taste and has a garlic smell to it. Best of all, Neem oil is completely organic and is safe to use around pets and kids.
According to the National Pesticide Information Center, neem oil interferes with the hormone system in insects, making it difficult for them to reproduce. It also reduces their feeding and acts as a repellent, pushing insects away from areas treated with it.
Neem oil is readily available as a spray bottle for plants and other foliage. The spray should be applied to plants every week or two, and you should notice a major reduction in Japanese beetles over this time.
One drawback to using neem oil is that Japanese beetles may move to other foliage in your yard that is not covered with the oil, so for it to be effective, you would have to cover all your outdoor plants and shrubs.
Geraniums
Another natural method for getting rid of Japanese beetles is to use geraniums as a toxic agent near Japanese beetle colonies. According to Michigan State University, geraniums can actually poison Japanese beetles.
Geraniums poison the system of Japanese beetles, which can lead to temporary paralysis or death after ingestion. Once the beetles become paralyzed after tasting geraniums, you can easily pick them away and dispose of them.
You can either grow geraniums in your yard or use a spray application of geranium oil to fight against the beetles. If you decide to grow geraniums, simply plant them close to other plants that you don’t want Japanese beetles feeding on. If you use geranium oil, mix 12 drops of oil in one cup of water and spray the leaves of plants. Japanese beetles will avoid the smell of the oil, thus avoiding your plants as well.
Beneficial Nematodes
All of the above natural products work great for killing adult Japanese beetles, but using beneficial nematodes is a great way to kill the underground grubs.
According to the University of California, beneficial nematodes are tiny, microscopic worms that hunt pests in the wild. The nematodes release bacteria into the grub’s bloodstream, which multiply and eventually kill the grub. The nematodes then feed on the dead grub until it is gone. After that, they go off in search of more grubs.
Beneficial nematodes are easy to use. Simply open the package, dump the nematodes into a bucket of water or inside of a garden sprayer, let the nematodes soak for one minute, and then spray over all of the soil where Japanese beetles feed on plants.
Be sure to use beneficial nematodes within 30 days of purchase, and always check the expiration date on the package to ensure freshness. Beneficial nematodes need moisture to survive, so apply them after it rains or make sure you irrigate the soil before releasing the nematodes.
Japanese Beetle Traps
Japanese beetle traps can be helpful in some situations, but in others, they can actually be more of a problem. Japanese beetle traps release a pheromone attractant and a floral scent to draw the insects, but they attract more than just the ones in your garden. In fact, the traps attract about four times as many beetles as would normally be in your yard, and only about half of them will end up in the bag.
Since Japanese beetle traps don’t work as effectively as other methods, I only recommend them as a last resort for humane insect disposal.
What Pesticides Will Get Rid of Japanese Beetles?
Natural remedies are great for the environment, but these alternatives don’t always work as effectively as pesticides. If you’re serious about Japanese beetle control, here are four effective and low-toxicity pesticides to use against these pests.
Bonide Pyrethrin Garden Insect Spray
This garden insect spray contains pyrethrin, which is a central nervous system antagonist for insects but not a big danger to pollinators, so it’s extra beneficial for your garden. However, some insects are highly resistant to it, so its effectiveness varies.
Bonide Garden Insect Spray prevents residue on plants and flowers, so many gardeners prefer this solution because it’s not an eyesore on their plants. To use against Japanese beetles, mix three tablespoons of product per one gallon of water. Use a gallon garden sprayer if possible.
Spray all outdoor plants liberally with the mixture but not to the point of run-off. Be sure to spray plants again after two or three days.
Delta Dust
If Diatomaceous Earth isn’t doing the trick, Delta Dust is a great alternative that uses a chemical compound called deltamethrin to kill Japanese beetles. Deltamethrin attacks the central nervous system of insects and has better resistance to moisture than DE powder.
Like any dust pesticide, Delta Dust should be applied inside a dust applicator. Apply a light dusting of the product to the leaves of plants to exterminate Japanese beetles.
Temprid FX
Temprid FX is very effective, but it’s also incredibly potent and should be used with the utmost caution.
Temprid FX’s two primary chemicals are imidacloprid and b-cyfluthrin. Both of these pesticides attack the central nervous system of insects, with b-cyfluthrin being in the less potent family of pesticides called pyrethroids.
When the chemicals are combined, Japanese beetles get a double dose of central nervous system attacks and will usually die within minutes of exposure.
Scott’s Grub X1
If beneficial nematodes are not working fast enough to destroy grubs, a product like Scott’s Grub X1 may be the answer.
This product is a soil treatment that can cover up to 10,000 square feet of your yard. The active ingredient is chlorantraniliprole, an insecticide that consistently reduces white grubs in the ground by up to 65%. It isn’t as water-soluble as some other insecticides, so you’ll have to mix it vigorously.
Scott’s Grub X1 comes in the form of granules, so you will need to use a spreader to effectively cover large areas of soil across your yard. It’s best to cover the entire yard to ensure you are applying the chemical to any possible hot spot for Japanese beetle grubs.
Apply this product to the soil at the end of the Japanese beetle season in early autumn. This will make sure that all grubs are killed and will not emerge as adults the following spring.
What Can Prevent Japanese Beetles?
To prevent a Japanese beetle infestation, it’s important to remember that the egg-to-adult life cycle occurs underground. Using a method like beneficial nematodes in late summer and early autumn is a great way to destroy them when they’re in the grub stage before they molt into adults next year.
If you work to destroy the life cycle, you destroy the beetle population. This won’t prevent roaming Japanese beetles from scouting your yard for feeding and mating spots, but it can prevent existing beetles from multiplying.
If you kill an underground colony of beetle larvae and see stray Japanese beetles in your yard, use one of the spray applications mentioned earlier for contact killing as needed.
Pesticides work quickly to kill Japanese beetles.
Pyrethrins are highly effective against this pest and pose less of a danger to pollinators like bees than other insecticides. It does no good to kill pollinating insects, therefore, avoiding the petal of flowers is best when using insecticides to treat Japanese beetles.
Final Thoughts on Japanese Beetles
Japanese beetles can cause widespread damage to plants and crops each year. If you ever see these insects in your yard, it is imperative to treat the soil immediately to destroy the life cycle before they emerge as adult insects.
Thankfully, Japanese beetles have very little resistance to pesticides, and there are numerous natural remedies that you can use to eradicate them. Your plants and flowers can’t survive a Japanese beetle invasion, so be sure to treat your yard to prevent this invasive species from taking over.
Frequently Asked Questions
Are pesticides harmful to pets?
Not all pesticides are harmful to pets, but if you don’t use them properly or expose your pets to too much at once, it could definitely harm them. Be sure to follow directions carefully when using pesticides, and if you’re nervous about harming your pets, opt for a natural solution instead.
Will Japanese beetles eat all my plants?
Japanese beetles don’t eat all plants, but they do eat over 300 different kinds of plants, many of which are common crops or household garden plants. They may not eat all your plants, but there’s a good chance they’ll eat most of them, especially for residents in the Eastern United States.
What are Japanese beetle's favorite plants?
Japanese beetles most frequently eat plants like American linden, apples,
apricots, cherries, peaches, plums, beans, birch trees, and more. However, the full list of all the plants they eat is very long.
Are there any animals that eat Japanese beetles?
Japanese beetles have several natural predators. Many wild birds, including robins, cat birds, and cardinals, will eat adult Japanese beetles. Rodents and small mammals like opossums, raccoons, skunks, moles, and shrews will eat beetle grubs, but they don’t usually eat adult Japanese beetles.
