Although they can be oddly beautiful, Japanese beetles (Popillia japonica) quickly lose appeal once they start eating your prized roses! Aside from destroying plants and trees, Japanese beetles can also ruin your lawn. The costs related to fixing the damage caused by Japanese beetles exceeds $460 million per year.
Japanese beetle traps to capture and kill the adult beetles that are eating plants, trees, and crops. When used correctly and in conjunction with other control methods, the traps can significantly reduce the presence of these pests and protect plants.
This article reviews the most effective traps on the market, provides information on identifying and reducing the presence of Japanese beetles, and supplies tips for how to place and use the traps.
Spectracide Bag-A-Bug Japanese Beetle Trap
If you’re looking for the best Japanese beetle trap, the Spectracide Bag-A-Bug Japanese beetle trap is at the top of the list. The trap uses a dual lure system, which is the most effective.
One lure contains the beetle’s natural sex attractant. The other lure consists of a floral scent that attracts Japanese beetles. By using both types of lures, the Spectracide Japanese beetle trap attracts up to five times more beetles than traps that use a floral lure.
The lures draw in beetles from a 5,000 square feet area. The box provides a chart with the number of traps needed to cover various size areas. An area ranging from 1/8 to 1/4 acres will need two traps, while areas less than 1/8 of an acre require one trap.
The lures last for the entire beetle season (approximately 12 weeks). If the floral aroma is no longer present, the lure may need to be replaced. The lures might become less effective if the bag is not changed frequently enough. This is because the smell of dead beetles begins to repel living beetles.
The trap uses replaceable bags that must be changed every few days. Depending on the number of beetles in your area, the bags may need to be replaced more frequently. In areas with particularly heavy infestations, users have reported that bags were filled within hours.
One downside is that the plastic bags can be ripped or torn by nocturnal animals, such as skunks for cats. To avoid this, the manufacturer recommends bringing the trap in each night.
- Uses a dual lure system that attracts two to five times more beetles than traps using a single lure
- Lures last for the entire beetle season
- One trap covers a 5,000 square foot area
- Avoids the indiscriminate use of harmful chemicals
- Uses replaceable bags that must be changed frequently
- The bags can be ripped or torn by animals, which may require the trap to be brought in and then placed outside each morning
- The use of the product is restricted in these states: AK, AZ, CA, CO, HI, ID, MT, NM, NV, OR, PR, TX, UT, WA, WY
Tanglefoot Japanese Beetle Trap Kit
If you want the best Japanese beetle trap, the Tanglefoot Japanese Beetle Xpando Trap Kit should be on your short list. Unlike most other traps on the market, the Tanglefoot trap uses a reusable plastic trap instead of plastic bags.
The plastic trap has an accordion-style design (similar to a gutter extender) that can be expanded depending on the number of beetles in your area. The trap is made from a durable, all-weather plastic.
Although the Tanglewood trap has a higher initial cost, you will save by not having to purchase replaceable bags. This savings can add up over time as the plastic bags on other traps need to be replaced every few days.
The Tanglewood plastic trap can be emptied, cleaned, and reused multiple times—even from one season to the next. The trap must be inspected periodically and emptied when it is approximately half full.
Although the air holes in the sides help to reduce the odor of dead beetles, too many beetles in the trap could lessen its effectiveness. The trap can be placed in water to kill the beetles before being emptied and cleaned.
Aside from being reusable, the plastic trap is more stable in various weather conditions (including wind) than the replaceable bags. Also, the plastic trap cannot be ripped or torn by an animal. This more durable design increases the Tanglewood trap’s effectiveness at containing beetles once they are trapped inside.
Like the other traps considered to the most effective, the Tanglewood trap uses a dual lure system consisting of a pheromone and a floral attractant. Using both types of lures attracts both male and female beetles. The lures should last for three months, which should cover the entire beetle season.
Although you can reuse the trap itself, you will need to purchase a new lure each season. One trap covers an area less than 1/8 of an acre. Two traps will be needed for areas ranging from 1/8 to ¼ acre.
- Uses a durable plastic trap that can be cleaned and reused—eliminating the need for purchasing replacement bags throughout the season
- Uses a dual lure with a pheromone and floral scent that attracts male and female beetles. The dual lure attracts 50% more beetles than traps that use a single lure
- One trap covers approximately 5,000 square feet
- Avoids the indiscriminate use of harmful chemicals
- Has a higher up-front cost than other traps. However, you won’t need to purchase replacement bags
- A replacement lure will need to be purchased for each season
- Some users reported that the plastic trap cracked and broke after several years of use
Bonide Beetle Bagger Japanese Beetle Trap
If you are seeking the best Japanese beetle trap, the Bonide Chemical Japanese Beetle Trap (also known as the Bonide Beetle Bagger) is one of the most effective traps available. The trap uses a dual lure system that is irresistible to both male and female beetles.
The first lure contains a pheromone that mimics the beetle’s sexual attractant. The second lure consists of a floral aroma that is naturally attractive to Japanese beetles. The use of both scents makes the trap successful at attracting and capturing beetles.
One dual lure covers a 5,000 square feet area. Similar to the other two traps that top our list, this means one trap will cover an area of 1/8 acre or less. Two traps will cover an area that is 1/8 to ¼ acres.
The lures will last for the entire beetle season. As with our other two choices, the lure can lose its effectiveness if the replaceable bags are not changed often enough. This is because the smell of the dead beetles acts as a repellent.
The Bonide trap uses hourglass-shaped, replaceable bags to catch the beetles. This hourglass design is more secure because it limits the area where beetles inside the bag can escape.
Like other traps that use replaceable bags, the bags must be changed every few days. However, if your area is experiencing a heavy infestation, the bags may need to be changed more frequently. Some users reported having to change the bags every 3 to 4 days.
One downside of the plastic bags is that they can be ripped or be torn by animals—freeing the trapped beetles and necessitating the use of a new bag.
- The plastic bag is shaped like an hourglass to trap beetles more securely
- Uses a dual lure system that attracts more beetles than traps that use a single lure
- Lures last throughout the entire beetle season
- One lure covers a 5,000 square foot area
- Avoids the indiscriminate use of harmful chemicals
- The trap uses replaceable bags that must be changed frequently
- The plastic bags used in the trap can be ripped or be torn by animals, which may require the trap to be brought in and then placed outside each morning
- This trip cannot be sold in these states: AK, AZ, CA, DC, HI, IDAHO, MT, NV, NM, ND, OR, SD, UT, WA, WY
OTHER PRODUCTS TO CONSIDER
The RESCUE! Japanese Beetle Trap shares a key feature with our top three choices—a dual lure system that lasts all season and covers the same square footage. The RESCUE! trap has a reusable nylon bag with a zipper bottom that allows the bag to be opened, emptied, and resealed for use. However, this trap isn’t one of our top picks because multiple users had problems with the bag ripping or the bottom becoming unsealed and releasing beetles. This lack of durability prevented us from putting this trap in our top three.
Like our top three choices, the Safer Japanese Beetle Trap with Attractant uses a dual-action lure that lasts for an entire season and covers the same square footage. According to the manufacturer, the Safer trap uses jumbo-sized plastic bags that are bigger than the bags used on other traps. However, the plastic bag is what kept this trap out of the top three. Multiple users had problems with the bags ripping and releasing the beetles. Other users commented on the overall flimsiness of the trap. For these reasons, we couldn’t include it as one of our top picks.
GENERAL INFO ON JAPANESE BEETLE TRAPS
What is the purpose of Japanese beetle traps?
Japanese beetle traps help protect plants and trees from being eaten by adult Japanese beetles. Once Japanese beetles begin eating a plant, they quickly “skeletonize” the leaves—filling them with large, irregular holes. Left unchecked, Japanese beetles can cause extensive and permanent damage.
The traps also help assess the Japanese beetle population in an area. If a trap becomes filled in one day, the surrounding area is most likely experiencing a Japanese beetle infestation. However, a trap that is barely filled after a week indicates an area with a minimal problem.
What attracts Japanese beetles?
The question should probably be “what doesn’t attract Japanese beetles” because the list might be shorter. Japanese beetles are attracted to a wide variety of field crops, ornamental trees, shrubs, garden flowers, and vegetables—almost 300 different species.
Japanese beetles prefer to lay their eggs in the turf of lawns, pastures, and golf courses. They also like the odor of diseased or rotting fruit. The United States Department of Agriculture (USDA) and its extension services have long lists of plants, trees, and crops that are particularly susceptible to Japanese beetles.
Where are Japanese beetle traps used?
The traps are used wherever Japanese beetles are causing damage to plants. Most infestations occur in the United States. The beetle is not a problem in Japan due to the presence of natural predators.
In the United States, the beetles are most heavily concentrated in states near to and east of the Mississippi River. However, partial infestations have slowly spread further west.
Japanese beetles are not as prevalent in the Western states, primarily because the area is not as hospitable for their survival. However, the first Japanese beetles were sighted in Oregon in 2016. As of 2015, only nine states didn’t have Japanese beetles.
The Japanese beetle has been living in the islands of the Azores since the 1970s. In 2014, the beetle was first spotted in Europe in Italy and subsequently spread to Switzerland.
Who typically uses Japanese beetle traps?
Gardeners and homeowners who want to protect their plants and trees from Japanese beetles are the primary users of the traps. The beetles are particularly attracted to treasured plants (like roses) and expensive ornamental trees (like Japanese maples). Farmers and orchard owners also use Japanese beetle traps to protect their trees and crops from damage.
How does a Japanese beetle trap work?
Japanese beetle traps have a relatively simple construction, with only two main parts—the lure and the bag (also known as Japanese beetle bags).
Once the beetles fly to the lure (which is located near the top of the attached bag), they crawl into or fall into the bag, where they become trapped and cannot escape. The bag fills with more beetles until it needs to be emptied or replaced. The traps must be hung from hooks or posts at the optimum height to attract beetles.
Most traps use plastic bags that can be removed and replaced as needed. One of our top choices (the Tanglewood trap) uses a hard-plastic trap that can be emptied, cleaned, and reused.
Do Japanese beetle traps work?
Yes! The traps are extremely effective at attracting and capturing Japanese beetles. However, one criticism of Japanese beetle traps is that they are too efficient—drawing such large numbers of beetles to them that they cannot trap them all. The “excess” beetles then land and feed on nearby plants. Tips for dealing with this are provided in the “Living with Japanese Beetle Traps” section below.
Are there alternatives to using Japanese beetle traps?
There are several alternatives to using Japanese beetle traps, each with their own benefits and drawbacks. Some methods are best used in conjunction with the traps. For example, targeting the grubs that will become next year’s adult beetles helps to reduce the overall beetle population.
Alternatives to Japanese beetle traps include the following:
- Pyrethrin-based insecticides. However, traps are more environmentally friendly than spray insecticides, which can harm helpful insects, such as honeybees and butterflies.
- Neem oil is a natural, non-toxic pesticide derived from the neem tree. When sprayed on plants, it helps control Japanese beetles (as well as a host of other pests) by causing them to stop feeding on the plants.
- Hand picking. Instead of using traps, some gardeners use a more hands-on approach—literally! Every morning when the beetles are sluggish, you can pick them off by hand and drop them in a bucket of soapy water. Even when they are more alert, Japanese beetles are slow and easy to catch.
- Biological control. Although biological control doesn’t provide an immediate way to eliminate the adult beetles eating your plants, they can be used to kill the grubs that will become next year’s adult beetles. One option is nematodes—microscopic parasitic roundworms that actively seek out and kill grubs in the soil. For Japanese beetles, the most effective are Steinernema glaseri and Heterorhabditis bacteriophora. Another option is to use soil bacteriums that affect the development of Japanese beetle grubs. Options are Bacillus thuringiensis and Bacillus papillae (also known as milky spore). These options can take as long as 2 to 4 years to become effective.
- Parasites. Releasing natural enemies or parasites of Japanese beetles can help reduce the population. Two such parasites (Tiphia vernalis and Istocheta aldrichi) are being studied by the USDA, but are not yet commercially available.
- Habitat Manipulation involves planting trees and plants that are less susceptible to Japanese beetles—helping to make the areas less attractive. Keeping trees and plants healthy also help as diseased plants and trees are particularly vulnerable to the beetles. Removing diseased or prematurely ripe fruit from trees or the ground will also prevent the beetles from coming to feed—thereby protecting the healthy fruit.
JAPANESE BEETLE TRAP BUYING GUIDE
When choosing a Japanese beetle trap, the most essential feature is a dual lure system, which will attract the highest number of beetles. All three of our top choices use dual lures, which combine a sex attractant (pheromones) lure and a floral scent lure. The lures last for an entire season and cover the same approximate area (5,000 square feet).
After the lure, you want to choose a trap that securely contains the beetles. Although most traps use replaceable plastic bags, the Tanglewood trap features a reusable plastic trap. Our top choices feature bags that have proven to be durable and reliable.
As far as pricing, the Tanglewood trap will have a higher initial cost. However, once you factor in the additional expense of purchasing replacement bags, the costs even out—and the reusable trap may prove to be more cost-effective overall.
The number of traps you need to purchase will depend on the size of the area you are trying to protect.
The top three brands in Japanese beetle traps are Spectracide, the Tanglewood trap manufactured by Ortho, and Bonide. All three are available for sale on Amazon and can be found at most garden centers or home improvement stores.
OTHER USEFUL INFORMATION ABOUT TRAPS FOR JAPANESE BEETLES
In the United States, Japanese beetles were spotted for the first time in 1916 at a nursery in New Jersey. It is believed the first beetles arrived on a shipment of iris bulbs from Japan. Since then, the beetle has spread north, south, and west.
Identifying Japanese Beetles
Knowing how to identify Japanese beetles is essential as people sometimes confuse them with other types of beetles. Japanese beetle traps will not work on different species of beetles or insects.
- Color: Metallic green body with iridescent coppery-brown wings. Rows of white hairs that resemble spots can be found on the sides of the abdomen
- Size: Adults range in size from 1/3 to 1/2 inches long and 1/4 inch wide. Males are usually smaller than females
Japanese Beetle Life Cycle
When trying to eliminate Japanese beetles, it is important to understand their life cycle. This is because most beetles stay near the area where they emerged from the ground. If there is a large amount of grubs in the soil, a massive infestation of adult beetles can be expected the following year, unless steps are taken to kill the grubs.
The beetle’s life cycle is approximately one year long and starts when the female beetle lays white, oval eggs in the soil about two to four inches deep. During each mating cycle, the female lays between one to five eggs. The mating cycle is repeated, and most females lay approximately forty to sixty eggs during her lifetime. Most of the egg laying happens during July and ends during the first week of August.
The eggs hatch in approximately ten days, at which point they turn into grubs. The grubs are shaped like the letter C and are cream-colored with brown heads and three pairs of legs. When mature, the grubs are about one inch long.
During August and early September, the grubs feed on the roots of grass, which can cause brown and blotchy patches in the grass. In the middle of October, the grubs move deeper into the soil—anywhere from six to eighteen inches deep—and remain inactive until the spring.
In late March or early April, the grubs wake up and move upward to feed on grass roots. In late May, the grubs cease feeding and being to pupate. Japanese beetle pupae are cream or reddish brown and are about a half inch long. Once they reach their full size, they emerge from the ground as adult beetles—usually in June. In warmer climates, emergence may take place earlier. Once Japanese beetle “season” begins, it lasts for about three months.
Assessing for Japanese Beetle Grubs
One way to find out whether you’ll be having a Japanese beetle problem is to survey your lawn for grubs. The best time to do this is in August. At this point, most of the eggs should have hatched, and the grubs will be about an inch long.
If you have brown or dead areas in your lawn, check that area for grubs. If grubs are found, this area of your yard should be treated. However, the density of grubs can vary widely in a small space. Therefore, you want to take several samples from random locations to get a better idea of where you’ll need to treat for grubs.
- To survey for grubs, use this method and calculation provided by the USDA’s Managing the Japanese Beetle: A Homeowner’s Handbook
- Dig a square hole with a shovel that is approximately eight inches wide by eight inches long and three inches deep
- Flip the sod over onto a newspaper and search the grassroots and soil for grubs. Also, inspect the area around the hole you removed
- Record the number of grubs found in each location where you dig a hole
- To find out the number of grubs per square foot, multiply the number of grubs you found by 2.25. You should consider treating areas in your lawn with more than ten grubs per square foot
- Once you’re finished with the removed sod, put it back into the hole and add water to help it recover
If you need to treat your yard, you can choose between insecticides or biological control, which are briefly described above.
LIVING WITH & USING JAPANESE BEETLE TRAPS
Once you’ve purchased a Japanese beetle trap, the most critical part is placing it correctly so it works effectively. Pay careful attention to and follow the manufacturer’s guidelines for trap placement. Some general guidelines include the following.
Where to Place Japanese Beetle Traps
- Place the traps as far away from the plants you are trying to protect. An optimum distance is 30 feet. If possible, place the traps next to a plant or tree (e.g., pine tree or boxwood tree) that isn’t attractive to the beetles
- Install the traps downwind from the plants you are protecting. Otherwise, you risk inadvertently causing the beetles to fly over the plants you are trying to protect while on their way to your trap—thereby diverting them to the plants instead of the trap
- Hang the traps at the correct height—approximately 13 centimeters above the ground. This is the height at which the beetles fly, so it ensures they won’t miss the trap
Tips for Making the Traps More Effective
- Place buckets of soapy water under the traps to capture beetles that don’t make it into the trap
- Another way to capture excess beetles attracted to traps is to place the traps near geraniums. Research has shown that Japanese beetles become paralyzed after feeding on geranium petals. According to the Agricultural Research Service (ARS), within 30 minutes of eating geranium petals, beetles rolled over on their backs and remained paralyzed for several hours. Although the beetles eventually recover, this gives you time to squish them, pick them up and put them in soapy water, or leave them to be eaten by predators. Savvy gardeners have begun using geraniums as “sacrificial” plants to protect their more treasured plants
- Place the traps as early in the season as possible to prevent the females from mating and laying eggs
- Replace the bags (or empty and clean the trap) frequently so the smell of dead beetles doesn’t repel the living beetles you want to trap
- Because Japanese beetles can fly long distances, attempts to reduce the population are most effective when done throughout a community. Enlisting your neighbors into your efforts to trap and eliminate beetles will be more effective than going it on your own. Otherwise, your traps may simply attract the beetles that are emerging from your neighbor’s yard
Tips for Disposing of Dead Beetles
Are you wondering what to do with the dead beetles collected in your Japanese beetle bags? If you own chickens, they’ll love to eat them! You can also check with nearby farms to see if they are interested.
Putting the dead beetles in your compost bin is another option. Sealing them in plastic bags and tossing them in the trash is another alternative.
One creative gardener used the bags of dead beetles to protect her cherry tree. When her trap bag got full, she punched holes in it, pounded on it, and hung it on the tree. The smell of the dead beetles acted as a repellent. Of course, the downside to this method is the stinky smell of dead beetles, which may not be appreciated by everyone.
Hopefully, this article has provided you with an understanding of the Japanese beetle and the role that Japanese beetle traps play in reducing the damage caused by these pests. By using our top picks for traps and guidelines for placement, you should significantly reduce the damage caused by these pests, which are the bane of gardeners and homeowners.