Battling Japanese Beetles: Tips for Banning Them from the Garden

Popillia japonica

It just isn’t summer in the northeast without Japanese beetles (Popillia japonica) tearing through raspberries, roses, and other plants gardeners tend to hold near and dear.

Their voracious appetite is matched in intensity with an innate difficulty to exterminate, or even to repel. They’re a problem for gardeners of every level, and their constant westward expansion means the Japanese beetle won’t be a predominantly East Coast problem for long.

When it comes to pest problems, a little knowledge goes a long way. After all, let us not forget the immortal wisdom of G.I. Joe who said, “Knowing is half the battle.”

Macro photo of Japanese beetle on a leaf.

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This applies quite well to Japanese beetles. There are no guaranteed ways to eliminate these insects from your garden, but we can take steps to minimize their presence and strive to eliminate it when the beetles show their coppery butts on your rose buds.

We’ll take a brief look at where Japanese beetles originated in the United States, gain an understanding of their life cycle, and go over how to prevent and eliminate these pests from your garden.

Strap yourself in because we’re goin’ to beetle town. First stop: Riverton, New Jersey.

Origins and Arrival

Japanese beetles made their first known appearance in the United States in 1916, in Riverton, New Jersey. However, unlike the bowl-cut Beatles who gave us songs like “Mother Nature’s Son” and “Yesterday,” these beetles were an unwelcome addition to the area.

Blue Japanese iris flowers in foreground, Japanese style stone garden bridge in the background.

The best guess for their actual origin in the United States was that they were hiding inside of a shipment of Japanese iris. A few years under the radar is all it took to establish a breeding population. Authorities attempted to control and eradicate these pests, but by 1920, the efforts and associated programs were given up.

Agreeable weather, no natural predators, and a limitless supply of irrigated turf provided a haven for this invader. The combination of these three factors explains how they’ve established such a firm foothold in the US, and why they cost half a billion dollars a year in prevention and management programs.

Japanese Beetle Life Cycle and Habitat

For a creature that spends the vast majority of its life underground, these pests cause a tremendous amount of damage. That’s because every stage of their life curses them with bottomless hunger.

Graphic that includes the life cycle of a beetle with images of each state from egg, to larva, to pupa, to adult.
The life cycle of a bark beetle, very similar to what a Japanese beetle undergoes.

Let’s start by looking at the most commonly sighted phase of their life cycle: the adult beetle.

Admittedly an attractive insect, Japanese beetles reach a length of up to one-half inch and can easily fit on the top of a penny. They have a coppery-bronze set of wings, a brilliant emerald green head, and a nice smattering of whites and blacks to round out their color palette.

We often spot these guys on some of our favorite summertime plants, like roses and raspberries. It’s uncommon to spot a single beetle because mature specimens emit a sort of attractant pheromone when they’re eating. When others of their ilk catch wind of it, they flock to the source and proceed to feast.

A single Japanse Beetle (Popillia japonica) destroying a rose flower.
The tattered remains of rose petals.

The individual beetle does a relatively minor amount of damage, but when one eats, others will inevitably be drawn to the pheromones. It is in these mass quantities that the real damage is done.

The adult phase of the life cycle lasts for about thirty to fifty days. That’s why there’s often a massive swarm of the things where there was nothing only a few days earlier. They need to eat, reproduce, eat, and reproduce again, as many times as possible, in that brief window.

Macro image of a Japanese beetle eating holes in a rose leaf.
A Japanese beetle eating its fill of a rose leaf.

The females will fly to an area of turf grass and lay an average of three eggs a few inches into the soil. They can repeat this process every twenty-four hours. Once the eggs are laid and are given time to hatch, the next life cycle begins.

The Gluttonous Grub

You know those big dead patches in your lawn, the ones where the grass is browning out? If you live on the Eastern Seaboard and you were to cut a square-foot section in the turf and roll it back like a carpet, chances are you’d find an assortment of grubs in the top few inches of the soil. And a sizable number of these are the grubs of the Japanese beetle.

The grub life cycle lasts for about ten months. These greedy guys will munch on grass roots and tend to cause those big brown patches in your yard. They thrive in well-watered terrain but will dig themselves deeper into the soil during times of drought.

Japanese beetle grubs laying in freshly turned top soil.
The grub phase as seen in its incubatory soil.

During the winter months, the grubs will typically dig themselves into the soil to wait out the cold. They’ve been observed to dig themselves as far as a foot into the soil during these cold spells. They don’t do much damage throughout this brief stage, but just you wait until spring.

When the weather warms up, these babies will perk right up and burrow their way to the roots of your lawn, munching away. They cause no small amount of damage to turf at this point, as they prepare themselves for their change to adulthood. They’ll emerge from the soil and start the life cycle all over again.

Read our guide on grub identification and control here.

“Waiter? Table for Fifty, Please.”

I’ve got some in-laws I don’t care for (who doesn’t?). They’ve got bland taste buds; boiled potatoes and cabbage with a sprinkle of pepper is the limit for what they will tolerate. So, my trick for minimizing their dinner visits is to revisit my favorite Central American recipes and cook up a spicy meal so hot it’ll make their heads spin.

Many Japanese beetles clustered on a plant, eager for a meal.
Someone pass the salt?

I kid, I kid. Hopefully that got a bit of a groan or maybe even a chuckle out of you. But the premise is solid for how to deter damage from Japanese beetles: don’t plant what they want to eat.

There we go! Problem solved, right? Wrong! The situation with these guys is that they have an incredibly diverse selection of plants they want to eat.

Seriously, it’s a list of over two hundred different species, and most of the items on their menu are our favorite and most valued plantings. Below you’ll see a generalized list of plants Japanese beetles prefer paired with an offering of plants they tend to stay away from.

Safe to Plant:

On the Dinner Menu:

In my experience, I’ve seen more damage done to roses, raspberries, and fruit-producing trees than anything else.

The individual beetle doesn’t consume a gross amount of vegetation. It is when groups of the things start to pile up on those delicate rosebuds and delicious raspberries that the real damage is done.

The beetles will eat only the leafy green bits and leave the leaves skeletonized.

Japanese beetle on a skeletonized rose leaf.
Skeletonized leaf after feeding.

As for turf, the grubs will tear apart the roots of your lawn and leave vast swaths of brown and dead turf to repair. Every stage in the lives of these insects is destructive.

So, some of our favorite and most useful plants are also highly favored by Japanese beetles – sounds like they’ve got good taste. But what can we do to limit their damage, short of altering the entire landscape?

An Ounce of Prevention

Fortunately, there are a few easy, low-impact methods we can employ to protect our gardens. In addition to selecting plants that are generally avoided by the bugs, we can help to make our lawns unappealing and inhospitable during the grub stage of their life cycle.

Female beetles are drawn to well-irrigated turf to deposit their eggs, and the grubs happily chew up the roots of our nice, green lawns. As touched upon earlier, America’s obsession with a vibrantly green and thick lawn has provided the perfect nursery for these invasive pests.

One of the most effective methods for limiting future generations of the pest is to limit how often you water your lawn.

A cluster of Japanese beetles on top of rose branch that has been stripped of vegetation.
When amassed and in the morning hours, simply pick up or shake the beetles into soapy water.

This is also advantageous in other ways. Many areas in California and Washington state are promoting the slogan “Brown is the new green” in an effort to minimize water use in drought-stricken areas. By allowing our lawns to go dry we are minimizing our water usage, and making the landscape far less attractive to Japanese beetles.

For those who simply don’t want to let their lawn go dry, consider letting it go high instead! Mike McGrath of the You Bet Your Garden radio show suggests that allowing your lawn to stay at a height of about three inches, coupled with no watering during dry spells, can prevent the female beetles from laying eggs in the soil.

Take care and be aware that there’s a difference between letting your yard go dead, and minimizing your water use. We have an excellent feature on xeriscaping that explains this process very well.

A Pound of Cure

Because of the mobility of these pests, it’s difficult to truly control them without applying nasty chemicals. The homeowner needs to spray everything the beetles eat or apply granules to the lawn over large areas including trees, roses and other types of perennials, and fruits and vegetables.

Even the pheromone traps often seen for sale tend to do more harm than good, by attracting the beetles to a new area. On top of that, the chemicals tend to be indiscriminate in their range of damage, doing harm to beneficial pollinators like honeybees and the friendly aphid-destroying ladybug.

Soapy Water

The most effective method of taking care of an insect infestation is to mix up a batch of homemade insecticidal soap. A ratio of two tablespoons of dish soap to one gallon of water yields good results.

In the morning, while the insects are still languid and relatively inactive, manually pick them up and drop them into the water.

If you don’t want to touch them, you can tap the leaves of whatever plants they’re hanging out on and watch them drop into the water instead. This can be a time-consuming practice but it yields the best results.

Japanese beetles with damage foliage in the garden.
The beetle is just one of several factors adversely affecting this plant.

Predator Controls

Consider that a few common backyard species will feed on the beetles, including European starlings, spiders, and assassin bugs. They don’t seem to typically do enough to significantly help the problem, but they have been observed eating the beetles.

My uncle has chickens, and he tells me that he lets them run wild through the raspberries. They absolutely love eating the Japanese beetles. Must be a chicken delicacy.

Ever see a skunk nosing its way through your yard? It might be making a mess, but it’s also eating up those nasty grubs. Sometimes it’s worthwhile to take a small hit on your turf in exchange for a reduced beetle population.

Moles are similarly inclined to devour grubs but will also leave tell-tale trails around your yard. Fortunately, the moles don’t bother plants and are single-mindedly hunting for grubs and the like. If you allow the moles to eat their fill of grubs until it’s no longer a problem, you can then easily repel them from your lawn.

Mix a solution of about 1/2 cup castor oil and 1/2 cup concentrated dish soap. Mix about 3 tablespoons of the mixture into one gallon of water in a bucket or watering can. Sprinkle the areas of your yard where you don’t want moles to go, and they should be readily deterred. Easy!

Parasitic Insects

Another great option for taking care of Japanese beetles (and an assortment of other pests like sawfly caterpillars and grasshoppers) is introducing a parasitic fly or wasp.

The Spring Tiphia is a Chinese native introduced to the United States to combat Japanese beetles. The wasp will hunt down and lay its eggs on the grub. The wasp eggs hatch and eat the grub from the inside out.

Tachinid flies have a similar habit, except that they find adult Japanese beetles and lay their eggs on the insect itself. There are a variety of other methods by which these flies deposit their eggs, but the important part is that they kill these pests.

The Spring Tiphia is attracted to flowers such as forsythia and peonies, while the Tachinid fly is attracted to large, flat masses of florets like you’d see on Queen Anne’s lace, cilantro, buckwheat, and clover. Establishing these plants is an excellent method for attracting beneficial insects to your garden and your yard.

Japanese beetle crawling on a yellow dahlia bud.
A foolish Japanese beetle on a dahlia bud, one of the plants known to attract beneficial parasitic insects.

Milky Spore

There are a few additional biological methods to employ when combating grubs: milky spore disease, and beneficial nematodes.

Applied as a dust to your lawn, milky spore is an ingested bacteria that only damages Japanese beetle grubs and larvae. It’s available from Arbico Organics.

A box of milky spore powder.

St. Gabriel Milky Spore Powder

Most folks use a dust tube like the one show below for application.

A green tube designed for dispensing milky sport, fertilizer, and powdered pesticides.

All Purpose Dispenser Tube

It is also available in granules for use in spreader or broadcaster. You will also find the granular product at Arbico Organics.

A plastic bag containing granular milky spore.

St. Gabriel Granular Milky Spore

Milky spore contains a bacteria that will eventually kill the grubs, then be dispersed back into the soil.

It’s a highly focused bacteria that is safe to use around animals, children, well water, and pretty much anything except Japanese beetle larvae.

Beneficial Nematodes

In the case of nematodes, not all types are destructive. Some of them can help improve soil quality and keep grubs down to a manageable level, Japanese beetles and other species.

And you can purchase them to add to your yard and garden.

The nematode Heterorhabditis bacteriophora is one of the specific species that attack Japanese beetles. You can pick up various quantities through Arbico Organics in their NemaSeek™ – Hb line.

A box containing NemaSeek Hb Beneficial Nematodes.

NemaSeek™ – Hb Beneficial Nematodes

I prefer to use a product that contains multiple nematode species that target a plethora of bad insects like this NemAttack product from Arbico Organics.

NemAttack Triple Threat Beneficial Nematodes

It contains three distinct nematode species including H. bacteriaphora, S. carpocapsae, and S. feltiae that all target different creepy crawlies.

For the best results, add these babies to water and spray into the soil with a pump sprayer.

You can read all about controlling pests with beneficial nematodes here.

Chemical and Organic Pesticides

As a last resort, we can use various chemicals to control this pest. Always make sure to wear proper safety attire when using any chemical control. And most importantly, READ THE LABEL to ensure you are using the product as directed.

Natria Liquid Neem Oil via Amazon

Neem oil and horticultural oils are effective when dealing with adult insects and are approved organic pesticides. Many act as an obstruction to feeding so that insects can’t eat or have difficulty eating the treated plant. They are also less damaging to the environment than many other solutions.

Chapin 2-Gallon Home and Garden Sprayer via Amazon

Although these products are usually available in a pre-mixed solution, you can also buy a concentrate that you add to water and apply with your own sprayer.

Bottle of Bonide Horticultural Oil Concentrate.

Bonide All Seasons Horticultural Oil Concentrate

With something like neem oil, regular applications are more effective. Buying the Neem concentrate or the horticultural oil concentrate (like this one from Tractor Supply) along with a handheld sprayer is usually the best route to take, in terms of future cost savings.

Green bottle of Safer Brand Neem Oil Concentrate Insecticide.

Safer Brand Neem Oil Concentrate Insecticide

There are also several grub control granular applications you can apply to your lawn.

Bayer makes a popular product that is available from Amazon. But be sure to rely on chemicals as a last resort. Before you use it, check your lawn to see if grub control is even needed.

BioAdvanced Season-Long Grub Control

With a good soil knife or a spade, you are going to inspect the ground beneath your lawn.

Find a section of the lawn where you can remove a square-foot piece of turf. Sift through the soil and see if you find any grubs. If you find less than six grubs per square foot, there is no need to chemically treat the soil. More than six, and you’ve got grounds for using granules.

Read our tips for repairing dead patches in your lawn, and our feature on maintaining a healthy lawn if you have that rolling green carpet already and want to keep it going strong!

Retailers also sell those Japanese beetle traps designed to attract the bugs and catch them in a nice bag.

Spectracide Bag-A-Bug Japanese Beetle Trap via Amazon

As we now know, the beetles are attracted to the pheromone inside of this trap and will quickly swarm to the source point, but not necessarily the trap itself. Add to this a range of about one mile traveled per beetle and you’ve got a recipe for an infestation.

The only place to use these traps is in rural areas, and only when you can place them about a quarter mile away from your garden.

Is Your Skin Itchy Yet, Talking About These Bugs?

I’m as soft-hearted as they come and have a difficult time killing even problem insects. I usually make it through a few dozen Japanese beetles before deciding I’ve killed enough and will let nature take its course. This mindset isn’t for everyone, but it’s good to keep your measure of acceptable loss in mind.

These bugs can cause a ton of damage and should be outright banned from gardens… but they aren’t. Like it or not, they’re here to stay.

We can do our best to minimize the damage they cause and prevent their populations from growing in the first place. But if there’s one thing gardeners know, it’s that we’re all part of the same garden.

Japanese beetles eating leaves which have been partially skeletonized.

Our efforts at cleaning house may be an exercise in frustration, but it’s also an opportunity to make peace with what is out of our control – even those pesky Japanese beetles have a place in the story.

Have any custom tricks for getting rid of Japanese beetles? Maybe you’ve got a story to share about losing all of your delicious plums! Tell us about it in the comments – we’d love to read all about it! And for more on ridding your garden of common pests, be sure to check out more of our articles on the topic.

Photo of author


Matt Suwak was reared by the bear and the bobcat and the coyote of rural Pennsylvania. This upbringing keeps him permanently affixed to the outdoors where most of his personal time is invested in gardening, bird watching, and hiking. He presently resides in Philadelphia and works under the sun as a landscaper and gardener, and by moonlight as a writer. An incessant questioning of “Why?” affords him countless opportunities to ponder the (in)significance of the great and the small. He considers folksy adages priceless treasures and is fueled almost entirely by beer and hot sauce.
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catherine (@guest_2093)
5 years ago

love what i have read so far….AND Matt sounds like a great guy…. interesting for sure….and knowledgeable!!! i’m trying to learn everything (lol) especially those dang japanese beetles !!!!!!!!!

Barbara Taylor
Barbara Taylor (@guest_31668)
Reply to  Matt Suwak
5 months ago

This is great reading, however, in Montreal, Quebec, Canada where I am living, for the first time I have seen this beetle today! There were several together as you mentioned, but I am on the 4th floor on an apartment block and they are on my flowers (mostly Chrysanthemums). Should I use the powders or other suggestions for using in the soil of each container? I would love to hear back as soon as possible please as we spent a few hundred $ in plants and soil. Thanks in advance.

Nan Schiller
Nan Schiller(@nanschiller)
Gardening Writer
Reply to  Barbara Taylor
4 months ago

Hello Barbara –

Your best bet is to hand pick the pests and drop them into soapy water to destroy them.

Last edited 4 months ago by Nan Schiller
Pamela O’Connor-Chapman
Pamela O’Connor-Chapman (@guest_4022)
4 years ago

Thank you. A most helpful article. I am trying so hard to have a garden that is is healthy and good for wildlife. I do love roses and so do these darn beetles and unfortunately my property is adjacent to a golf course.
I appreciate your closing comments in the article….

Frank Phillips
Frank Phillips (@guest_4764)
4 years ago

Thanks for the guidance Matt
I duct-taped a funnel to a handheld cordless vacuum like a car vacuum walk down the road of my hemp plants vacuum them up as I went and then put them in soap when I was done I collected hundreds at a time we’re going to get rid of them as best I can what’s a little bit of work and walking the five acres I planted

Ginnie (@guest_4801)
4 years ago

Japanese beetles do attack Magnolia bushes in Iowa

Kim Wilson
Kim Wilson (@guest_4885)
4 years ago

They have been attacking my hibiscus plants in upstate NY

Stella (@guest_6565)
3 years ago

I understand one can trap Japanese beetles and then put in blender with water, whirl away, then put all thru a sieve and then spray on ones plants and then beetles won’t bother them. Is this bad for bees, pollinators, or plants? I would not mind whirling away the beetles but would this be negative to plants or beneficial insects? Thank You.

Jolene (@guest_16254)
Reply to  Stella
1 year ago

Hi Stella, I did this very thing last summer as an experiment. We collected about 50 by hand in 1/2 gallon bottles (10 of these) with dishsoap and water. We used an old blender and poured through a strainer and sprayed daily. We sprayed on day 1 of their arrival through the 8 weeks of their adult stage existence on our plum, apple trees, blueberry, beans, and our burning bush that they attack relentlessly every year. In our situation, it didn’t really do anything. It didn’t minimize the population at all it seemed. I’m guessing the pheromones they emit while… Read more »

Stephanie Eastwood
Stephanie Eastwood (@guest_18631)
Reply to  Jolene
1 year ago

Thanks for writing to share your experience spraying japanese beetle puree on plants, Jolene. Readers will be glad to know it isn’t worth the effort. I appreciate your contribution to gardeners’ knowledge!

Donna Skellchock
Donna Skellchock (@guest_7549)
3 years ago

Loved this very fun and thorough article Matt. I may have missed it, but I was looking for the 2-3 timelines for applying grub treatment to lawns. I loved the part in your bio about asking “why” incessantly. hahahaha!
I spend copious amounts of time Googling stuff. Can’t help myself. hahahaha! Excellent article! donna

Teresa A Rogers
Teresa A Rogers (@guest_7664)
3 years ago

My barred rock hen adores beetles and follows me around the yard as I shake them off my rose of sharon to her. Sometimes I tap them off into a bucket of water and let my chicken play “bobbing for beetles”. She is excellent all-natural beetle control.

Janine (@guest_8948)
3 years ago

I use an empty water bottle with some water and soap added, and I use the cap to help guide the little suckers in. Was thinking though… Should you remove the decimated leaves from the plants that they’ve feasted on? Just wondering if there’s any pheromones left on the leaves…

Allison Sidhu
Allison Sidhu(@allison-sidhu)
Reply to  Janine
3 years ago

Great question, Janine. According to this article by Tim Johnson of the Chicago Botanic Garden, you shouldn’t have to worry about any pheromones that remain, but rather, the chemicals that the damaged leaves are exuding, which will continue to attract more of the beetles. Removing the damaged foliage is a good idea to prevent further pest problems.

Michael B Anenberg
Michael B Anenberg (@guest_16763)
1 year ago

For me… seems like all the “natural ways” do not work. I have tried them. They don’t work. So, it’s chemicals all the way baby! Kill those suckers! Cry, Havoc! And loose the chickens of War!