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Japanese Beetle

Program Update and Next Steps 

For the past several biennia, the Japanese beetle eradication program has been funded through one-time General Fund or Lottery Fund appropriations from the Oregon Legislature, separate from ODA’s base budget. During the 2025 legislative session, a bill to continue this funding did not pass, and the end-of-session budget package did not include funds for the program. 

In the absence of funding, the ODA will not be continuing Japanese beetle eradication operations in 2026. ODA would like to extend gratitude to the many residents that have participated in the program over the past eight years. Support and cooperation from local communities and city governments within the infested areas made for a 92% decrease in the emergent population of JB from 2017 (when the program started) through 2025. Through targeted treatments and widespread detection trapping, ODA prevented the beetles from spreading into new areas of the state. This has greatly benefited our local agriculture, gardens, public parks, and urban forests. Though the future is uncertain, it is predicted that Japanese beetle will spread into new areas and become established in other parts of the state in the absence of continued treatment efforts. If you are interested in learning more about how to manage Japanese beetle on your property consult this treatment information guide or scroll down to the respective treatment tab below.

Japanese beetle Pest Status in Oregon

Over the past nine years, the Oregon Department of Agriculture (ODA) has been working with local communities and city governments on a multi-year project to eradicate the Japanese beetles before they become established in Oregon. ODA trapped 1,919 Japanese beetles in 2025, a 65% decrease from the number of beetles trapped in 2024. However, most of the catches (~78%) were isolated to one farm. ODA finished the last treatments (~950 acres) for the program in May of 2025. 
JB Count 2025-10-31.png

The Japanese beetle (Popillia japonica) continues to pose a significant pressure on Oregon and other western states. The largest infestation in Oregon was found in 2016 in the Cedar Mill, Bonny Slope, Oak Hills, and Bethany areas of Washington County.  This invasive insect pest can be destructive in multiple life stages, causing damage to over 300 types of plants including roses, hops, grapes and a myriad of ornamental plants. If left unmanaged, the current population will continue to grow and spread to new areas within Oregon. Increased beetle populations lead to more pesticide use to protect crops and gardens. 

How can I prevent the spread of Japanese beetle? 

If you live in or near the infested area there are a couple of ways you can help limit the spread of Japanese beetle. The best way to help limit the spread of Japanese beetle currently is to ensure you are not moving any plant material, including outdoor potted plants, to new locations outside of Washington County. Also, please refrain from participating in any plant swaps if you are within the infested area. Japanese beetle can be moved in a variety of ways, including in potted plants. It is likely that the current population was introduced from a potted plant that was moved into the neighborhood from a Japanese beetle infested area outside of the state. 




Identify a Japanese Beetle

The Japanese beetle has several unique features that make it different from other insects in Oregon and the western United States. Below is an image that shows how to tell the difference between the Japanese beetle and similar “look alike” insects.



Eradication Project (2017-2025)

Invasive Species in Oregon
According to the ​Oregon Invasive Species Council​:
“Invasive species are animals, plants, and microorganisms that are not native to Oregon and once here can reproduce so vigorously that they replace our native species. They pose a threat to key sectors of Oregon's economy that depend upon natural resources and native ecosystems. Agriculture, forestry, tourism, and water resource infrastructure, including hydropower facilities, are at serious risk of being adversely impacted by invasive species. Unchecked, invasive species individually and collectively have the potential to imperil public health and to transform ecosystems, resulting in widespread economic and environmental devastations.”
Threat to Oregon
Like many invasive species, Japanese beetles don't have natural predators in the United States to control their population. In the Eastern and Midwestern U.S., these beetles cause large-scale destruction to garden plants and agricultural crops.
Since the Japanese beetle is a major threat to important industries in Oregon, such as nurseries, turf grass, and specialty crops, the Oregon Department of Agriculture (ODA) is working hard to stop the beetle from spreading by using quarantines and treatments. The overall goal of eradication is to protect Oregon’s farming and agricultural livelihood from harmful, invasive pests like the Japanese Beetle.
This invasive beetle can cause damage at different stages of its life. As a grub, it feeds on the roots of grasses, which weakens the plant and prevents it from getting enough water, creating brown or dead patches in lawns. As an adult beetle, it eats the leaves, leaving a pattern called “skeletonizing,” which causes the leaves to break down and fall off. Plants like roses, grapes, fruit trees, and berry bushes are especially vulnerable to this kind of damage.
When plants lose their leaves, they not only become more likely to get diseases, but they also become stressed, have higher death rates, and can’t make as much food through photosynthesis. Without photosynthesis, important environmental benefits like clean air, healthy water in rivers and streams, and temperature control through shade are also affected.
The Eradication Project
When a new invasive species is found, an eradication project may be initiated to remove all life stages of the pest (adults, larvae, and eggs) and prevent it from spreading. The methods used for eradication depend on the pest’s biology and characteristics. If we don’t get rid of the pest, it could become established and remain in the state forever. The sooner an invasive species is detected, the better. Sometimes, early detection can catch just 1-2 pests. Biological experts use risk models and their knowledge of insect biology to determine if an eradication project is needed to protect the state from the devastating effects of an invasive species. Early detection and prevention programs are a critical part of protecting our state from invasive species.
Since 2016, when the discovery of a significant Japanese beetle infestation in WA Co. first occurred, the ODA has taken the above approach to eradicate the species from Oregon. Treatments in 2017 through 2025 have yielded a 92% decrease in the population. Unfortunately, due to a loss of state funding, the eradication effort in Oregon cannot continue.​

Japanese Beetles on Your Property

In the fall, winter, and spring, Japanese beetles are in their immature "grub" stage and feed on grass roots, which makes it harder for plants to get water. Dead patches in lawns or grass may be a sign of Japanese beetle grubs. In the summer, adult beetles feed on leaves, fruits, or flowers (Japanese beetles love roses!). Visit the “Identify a Japanese Beetle” section above to help with identification.


Note: Japanese beetles are often mistaken for boxelder bugs. If it's late fall and you're seeing many beetles inside your home, they are likely boxelder bugs, not Japanese beetles. Boxelder bugs are native to North America, not invasive, and aren't harmful, though they can be a nuisance as they look for warm places to stay for the winter. For more information on boxelder bugs and how to prevent them, check out the University of Minnesota Extension's guide.

Oregon Detections

The Japanese beetle was first discovered in the United States in a nursery in New Jersey in 1916. Since then, it has spread across the East Coast and Midwest, causing major damage to home gardens and crops. The beetles most likely arrived in Oregon when someone moved from an area already affected by Japanese beetles and brought a potted plant with them. Japanese beetle eggs and larvae live in the soil, which makes them easy to accidently transport without being noticed.
Things like plants, grass clippings, sod, and other yard materials can carry Japanese beetles from one region to another. To help prevent this, the Oregon Department of Agriculture (ODA) had previously set up a quarantine for yard debris in part of Washington County. For more details, check out the Yard Debris Quarantine section below.
There have been three separate beetle detections in Oregon in recent years:

  • Cedar Mill, Bonny Slope, Oak Hills, Bethany, Raleigh Hills, Cedar Hills, and Orenco in Washington County. These areas are where the largest and most widespread Japanese beetle infestation in Oregon was found in 2016. This population has since spread to areas of Multnomah and Clackamas counties and was part of the treatment area.  
  • ​Oakland, Oregon, a small population of 10 beetles was found in 2017. By 2020, no beetles were detected. This population was probably started by a potted plant brought in from a Japanese beetle-infested area. 
  • Portland International Airport. There is a constant risk of new Japanese beetles being brought in through cargo from infested areas. The airport was treated annually through 2025 to prevent these beetles from spreading. For over 40 years, the ODA has been successful in keeping the beetles from reaching other parts of the state.​​
  • Salem, Oregon, a single adult beetle was found in 2025. Additional traps were set in the area, but no further beetles were detected. 

Japanese Beetle Treatment

    During the state eradication project, a low-risk granular pesticide product containing the active ingredient chlorantraniliprole was used because of its effectiveness against Japanese beetle. That particular product is only available to licensed pesticide applicators, but there are other products on the market for general consumer use, including some that contain the same active ingredient. For information on these and other options, please consult this treatm​ent information guide​​.​

Yard Debris Quarantine

Japanese beetle yard debris quarantine will not be enforced at this time
Due to budget constraints the Oregon Department of Agriculture (ODA) cannot offer free yard debris collection and disposal services for residents living in the Japanese beetle yard quarantine. So instead, ODA is prioritizing pesticide application and trapping in infested areas. In addition, to help monitor any possible spread, ODA will increase the number of traps placed for detecting Japanese beetle in areas where yard debris waste is brought for disposal.
Thank you to those who supported the quarantine from 2017 to 2022. ODA asks for the public's continued support. The best way to help limit the spread of Japanese beetle currently is to ensure you are not moving any plant material, including outdoor potted plants, to new locations outside of Washington County. Also, please refrain from participating in any plant swaps if you are within the treatment area.
Residents in Washington County can continue to use their curbside yard debris bins as usual.
For more information on where to take your yard debris material (for those within a treatment area), please consult this list of participating disposal sites: Yard Debris Waste Disposal Sites in Washington County

2025 Treatment Area Map

​Explore the 2025 Japanese Beetle Treatment Area

Use the map below to see if your property was in the Japanese beetle treatment area. In addition to Washington County and NE Portland, treatments have also been done in Oakland, OR, and at Portland International Airport in recent years.

2025 Treatment Area Map​​​​

Instructions for Using the Map:

  1. Click the button to access the treatment map.
  2. Once on the map, click the "Find address or place" icon.
  3. Enter your address in the search bar.
  4. A yellow arrow will appear, pointing to your address.
  5. If your address is within the treatment area, the map will show a blue outline and say, "Your property is located inside the proposed treatment area."
  6. If your address is outside the treatment area, the map will say, "No results found."

How You Can Help Protect Oregon’s Gardens and Agriculture:

If you live in or near the infested/treatment area, your cooperation is key to protecting Oregon’s plants and economy. Here’s how you can help:

  • Report suspected Japanese beetles found outside the treatment area to the oregoninvasiveshotline.org​.
  • Keep an eye out for any major beetle damage to lawns, roses, grapes, fruits, or other trees and shrubs, especially if it’s outside the previous treatment area.
  • Avoid the movement of plants and soil from infested areas.
  • If you detect Japanese beetle on your property, consider implementing integrated pest management strategies, many of which are readily available online for this species. 


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