How to get rid of Japanese beetles naturally and effectively

Japanese beetles are dangerous garden pests that damage most of the crops in both their adult and larval stages. In the US, these beetles damage over 300 plant species that are part of 79 different plant families. They become a threat to crops and the food industry such as grapes, apples, peaches, plums, roses, corn, and soft fruits and berries farming. However, the value of these fruits is more than $7.4 billion only for California which can be targeted by beetles.

Adult beetles cause leaves to become skeletonized, meaning they eat the part of a leaf between the veins. Whereas larvae eat the roots of grass under the ground and weaken lawns and crops. Learn how to get rid of Japanese beetles timely and effectively with traps and other natural methods with this article.

What Are Japanese Beetles?

The Japanese beetle (Popillia japonica) is an invasive species which are 0.6 inch in length and 0.4 inch in width. They have a copper colored body, thorax and head is in green color. These Japanese beetles send chemical signals which are called pheromones to call other beetles. The worst thing is that plants already damaged by these beetles start giving off scents that actually attract more beetles to come and feed on them.

Life Cycle

To effectively manage Japanese beetles, understanding their life cycle is key. These beetles have just one generation each year. Most adults emerge from the soil between early July and mid-August, feeding and laying eggs during this time. This is a short time duration when they’re most active. Take precautions in this small season to reduce their population for the next year.

• Eggs: All adult female beetles prefer to lay their eggs where the grass is healthy and moist, about 3 inches below the surface . 
• Larvae: Within a few weeks of being laid the eggs hatch, and the larvae begin to feed on plant material such as young grasses and organic material. They mature in c-shaped grubs. This is a destructive stage due to economic damage.
• Pupa: Grub, pupate in soil in spring such as a cocoon stage where it spins a protective covering to a pupal stage. The time it takes for this imago process to occur is 30-45 days.
• Adult: Adults beetles come out of the soil during late spring to early summer. These are flying insects who feed and mate so the life cycle repeats again. 

Problems Caused by Japanese Beetles

Japanese beetles are known for their voracious eating habits and can cause considerable damage to a garden.

• Leaves Get Chewed Up: Japanese beetles like to feast on the tender parts of leaves, which is why people usually see only veins left on the leaves. This causes the leaves to appear as leaf skeletons, a condition known as skeletonization. It screws with the plant’s health and its ability to generate food via the process of photosynthesis.
• Flowers and Fruits Get Ruined: These beetles feed on flower blossoms and move to ripen or soft fruit. This causes the fruit to be so destroyed that it cannot be sold at market.
• Corn Crops Get Messed Up: Japanese beetles nibble on silky areas of the corn plant in cornfields, preventing the kernels from growing as they should. This hits the corn yield hard.
• Grass and Lawns Take a Hit: The larvae of Japanese beetles, called white grubs, live underground and eat grass roots. This causes brown, dead patches all over your lawn.
• Crops Suffer and Yields Drop: Grubs also attack the roots of crops like maize, tomatoes, strawberries, and beans. This weakens the plants, slows their growth, and sometimes even kills them.

Top 5 Japanese Beetle Traps

Looking for an effective ways on how to repel Japanese beetles? These 5 traps are the best defense against these destructive pests available at Growcycle.

1. Bonide Japanese Beetle Trap
2. Safer Japanese Beetle Trap
3. Rescue Japanese Beetle Trap Refill
4. Bonide 32oz Japanese Beetle Killer RTU
5. Spectracide Bag A Bug Japanese Beetle Trap

1. Bonide Japanese Beetle Trap

The BONIDE Japanese Beetle Trap Kit is a  hassle-free way to attract and catch Japanese beetles. It uses a dual-action lure with floral scents and pheromones so that beetles come towards it. The trap is in hourglass shape to make sure that if beetles get in and there is no way to escape. Each kit comes with one trap, a dual lure, and two disposable collection bags.

This garden pests Japanese beetle remedy works all season and can protect up to 5,000 square feet, making it great for large lawns too. When the bags or lures come to end, no need to buy a whole new kit.

2. Safer Japanese Beetle Trap

The Safer Brand Japanese Beetle Trap is a clever way to deal with beetles by luring them with food to catch them in a trap. This all-in-one kit contains one trap, two jumbo bags, two bait packs, and a 48 inch stand to hang the trap at the ideal height so you can catch Japanese beetles easily.

Install the trap at least 10 feet from plants to prevent beetles from flying to them. When the bag is full, throw it out and replace it with a new one. If there are still beetles and the trap isn’t catching, replace the bait. After the infestation is contained, discard the trap. This spray-free solution is super convenient for gardeners.

3. Rescue Japanese Beetle Trap Refill

The Rescue Japanese Beetle Trap Refill is a pheromone-based lure system that reuses existing traps. Simply take the refill out of its pouch and place it on top of the trap. When beetles are drawn to the attractant, they run into the trap’s green panels and fall into the bag below, where they are not able to escape. This product is a safe beetle killer for plants without any harmful chemicals.

The biggest perk of this trap is that no poisons or harsh killing agents are used. Just hang the trap in an area out of reach of animals. This refill doesn’t just attract Japanese beetles; it also lures Oriental beetles, both of which are dangerous pests that can damage plants. Plus, the refill system is eco-friendly and reuse the trap for multiple seasons.

4.

The Bonide Killer is ready-to-use spray. Pre-mixed pest control option that kills Japanese beetles, also aphids, flea beetles, caterpillars, stink bugs, webworms, moths, and many other insects. This is a spray that can be used on vegetables, flowers, ornamental plants, trees and shrubs. It is sold in a 32-ounce container with a convenient spray nozzle, which makes it super easy to apply.

This spray is designed to be used at home, inside and out, including in greenhouses. It’s an ideal solution for anyone who seeks quick and efficient bug control without the hassle of mixing, or any difficult steps to follow.

5. Spectracide Bag A Bug Japanese Beetle Trap

The Spectracide Bag-A-Bug Japanese Beetle Trap is a powerful system that lures and catches Japanese beetles effectively. It uses a  technology with natural pheromones and floral scents, attracting 2 to 5 times more beetles than most other traps. Each pack contains stripes of vanes, a dual lure, 2 disposable bags and a hanging twist tie, but the stand needs to be bought separately. This trap works for an area of up to 5,000 square-feet, so it is great for large gardens.

This product helps protect roses, fruit trees, vegetables, and ornamental plants from beetle damage. Each lure stays effective for about 12 weeks, but replaces it when the scent fades. Spectracide’s fast action solution is great for anyone who is looking to get rid of beetles.

Natural Ways to Get Rid of Japanese Beetles

There are several easy and effective methods for natural Japanese beetle control to keep the garden safe. These approaches help people to repel beetles without using harmful chemical sprays.

Handpicking and Morning Collection

Handpicking method is suitable for small gardens rather than large-scale farms. Research proves that collecting beetles daily can reduce the population of beetles and foliage damage. Additionally it works best if doing the same process 3 times a day.

Japanese beetles are inactive in the early morning 8am due to cold weather, especially when there is morning dew. Also in evening time 7pm is effective because violet signals are not produced by beetles to call new beetles for feed.

1. Fill the bucket with hot water.
2. Mix a few drops of lemon or dishwashing liquid in water.
3. Pick beetles by hand or using a soft brush and put directly into the bucket.
4. They die in it because soapy water is lethal for them.  

Neem Oil Spray

Neem oil is a natural repellent and reproductive inhibitor which is a proven method to control Japanese beetle traps homemade spray effectively. It disturbs the feeding behavior of beetles and slows the reproductive process of them. Moreover, neem can also kill the grubs inside the soil if applied at the right time. 

When neem spray is applied on the plants they become less attractive and reduce the attack of beetles. It disrupts the process of mating and laying eggs which somehow help to control their next generation. Additionally, neem oil is not harmful for bees and other beneficial insects if used in a correct way. 

1. Mix a small amount of neem oil in 1 gallon of water.
2. Add surfactant in the neem oil solution so it adheres to the plants evenly.
3. Spray all over the plants specially on both the upside and downside of the foliage.
4. Apply regularly, especially after rain and watering.
5. Use this spray before the emergence of beetles from the soil. Means at the start of spring to disrupt their life cycle.

Insecticidal Soap

Insecticidal soap is a natural and non-toxic way to tackle Japanese beetles. It breaks down the beetle's protective waxy coating, drying them out and eliminate Japanese beetles organically. It’s typically made from potassium salts of fatty acids, which are safe for plants but deadly for pests. 

This approach is perfect for those who want to stay away from chemical pesticides and go for eco-friendly solutions. Some plants, like tomatoes, cucumbers, beans, gardenias, peas, plums, and cherries are sensitive to insecticidal soap. This method doesn’t give instant results, but with regular use, it can gradually control the beetle population.

1. Take pure liquid Castile soap for this spray.
2. Start with about 1 teaspoon of soap per gallon of water, and slowly increase it if needed.
3. Add 1 cup of cooking oil to the mix. 
4. Before spraying your whole garden, try the solution on a single leaf or small branch. 
5. Wait 24 hours to make sure there’s no bad reaction. If it looks good, go ahead.
6. Focus the spray on areas like leaf edges, flowers, or near fruits.
7. Reapply this solution every 7-10 days, especially if the beetle problem is big.

Row Covers 

Row covers are a fantastic, chemical-free way to protect plants from Japanese beetles. These lightweight fabrics allow air, light, and water to plants and keep beetles out. They act as a barrier, stopping beetles from landing and feeding crops, which prevents the crops from damage. 

The best time to use row covers is during the Japanese beetle feeding season. That’s when beetles are most active, and plants need the most protection. Row covers reduce plant diseases which are carried by beetles. 

1. Spread the fabric over the plants, leaving a bit of space so they have room to grow.
2. Secure the edges to the ground with boards, soil, or landscape pins to keep the wind from blowing the fabric away and to prevent beetles from sneaking in.
3. Create a tunnel-like structure with plastic hoops or PVC frames to support heavy fabric.
4. Few beetles insert under the covers, so check and remove them by hand.
5. Take off the covers when they start blocking pollination.

Beneficial Nematodes

The grub stage of Japanese beetles is their most destructive phase, when they feed on plant roots underground. Beneficial nematodes, like Heterorhabditis bacteriophora (HB) and Steinernema glaseri, are a super effective, natural way to tackle this issue. These tiny worms are released into the soil, where they hunt down and destroy grubs. 

These nematodes, inside the grubs, release a deadly bacteria that kills them in just a few days. Afterward, the nematodes multiply inside the dead grub, creating more worms.

1. Late spring or early summer is the best time to apply nematodes.
2. Nematodes don’t like sunlight or high heat, so apply them in the early morning or evening when the soil is cooler.
3. Water the soil well before and after applying nematodes to keep them alive and moving.
4. Mix nematodes with water and use a spray bottle, or watering can to apply them. 
5. Follow the product instructions carefully.
6. Repeat the process for heavy infestations after every 2-4 weeks.

Milky Spore Powder

To protect the lawn or garden from Japanese beetle grubs for the long run, Milky Spore is a great organic and sustainable option. Its active ingredient is Paenibacillus popilliae, a natural bacterium that only targets Japanese beetle grubs. Good bugs such as bees are perfectly safe.

Grubs feeding on the roots consume the milky spores. The bacteria reproduce inside the crickets and eat them from the inside out. These spores remain in the soil for years, attacking any new grubs that come along. Spores, when applied, can remain viable in the soil for years, decreasing the population by 5% a year.

1. Use in the fall when grubs are feeding in the soil.
2. Apply it by hand or with a lawn spreader to distribute it evenly.
3. Gently water the area after application to help the spores penetrate the soil.
4. Application varies according to the product, so always read the label.

The Bottom Line

Japanese beetles are a destructive insect for gardens that damage flowers, vegetables, and trees. But treatment is possible by using the right product at the right time. The organic pest control methods mentioned above are among the most effective ways to get rid of Japanese beetles. From ready made sprays to effective traps, everything is available at Growcycle, where the product quality is tested and trusted to prevent the garden from beetle attack.

Disclaimer: This material is for informational purposes only and should not be relied on for legal, medical, financial, or any other form of professional advice.

About the Author

Victor Miller

Environmental Journalist Focused on Sustainable Agriculture

Victor Miller is an environmental journalist at Growcycle, specializing in sustainable agriculture. With a passion for storytelling, he highlights the latest trends, innovations, and practices that promote ecological balance and responsible farming.