Japanese Beetle Eradication
Our progress
Mesa County’s aggressive efforts to combat the invasive Japanese Beetle are showing significant progress. The effort, in collaboration with the Colorado Department of Agriculture, Colorado State University Extension Office, focuses on targeted trapping, spraying, and containment. Data indicates that most beetle captures occurred within defined treatment zones, confirming that current strategies are effective in limiting the pest’s spread.
Looking ahead to 2026
- Expanded Treatment: Hotspots and border areas will receive additional focus to prevent migration.
- Sustainable Practices: Continued evaluation of pest control methods to ensure long-term effectiveness.
- Community Engagement: Residents’ cooperation is essential, as most treatment areas include private properties.
- Strengthened Partnerships: Collaboration with state and university partners remains a priority.
Help protect our Japanese Beetle eradication effort
Please do not purchase or install Japanese beetle traps on your property.
Our county is actively conducting a coordinated Japanese beetle detection and eradication program. As part of this effort, trained staff have strategically placed monitoring traps throughout the county to accurately detect beetle populations and measure control effectiveness.
While commercially available Japanese beetle traps may seem helpful, they can actually interfere with eradication programs. These traps use powerful attractants that can draw beetles from surrounding areas. In some cases, traps may attract more beetles to a property than they capture, potentially increasing local beetle activity and affecting the accuracy of official monitoring efforts.
Unauthorized traps can also make it more difficult for program staff to interpret survey results, identify infestation areas, and evaluate treatment success. Reliable monitoring data is essential for making informed management decisions and achieving eradication goals.
How you can help:
- Do not install Japanese beetle traps on private property.
- Allow county or authorized program staff to conduct monitoring and treatment activities as needed.
- Report suspected Japanese beetle sightings to the county's designated contact.
- Follow county recommendations regarding plant movement, treatment, and prevention measures.
By working together and relying on a coordinated, science-based approach, we can improve our chances of successfully eliminating Japanese beetles from our community.
Infestation Area Treatment Map
- The borders of the infestation are generally in the area between 24 Road and 27 1/2 Road between Patterson Road and H 1/2 Road.
- Properties outlined in red are subject to eradication efforts.
- Do you live in the Treatment Zone but haven't been contacted to give consent for Mesa County to complete free Japanese Beetle grub control treatments? Give us a call today 970-902-3886!
Information and resources
Property owners outside of the infestation area can prevent Japanese Beetle establishment in their area by completing grub control treatments with homeowner formulations or contacting a local turf management company.
Licensed commercial applicators for lawn care
- Bookcliff Gardens 970-242-7766
- Bookcliff Lawn Care 970-210-3774
- Colorado Vegetation Management 970-261-1304
- IHS Lawn and Landscape Maintenance 970-986-7927
- Jerry’s Pest Control 970-242-7455
- Liqui-Green Turf and Tree Care 970-256-1928
- Mesa Turf Masters 970-331-0913
- Peaceful Valley Irrigation and Landscaping 970-640-3478
- Penguin Pest Control 970-245-7711
- Thompsons Enterprises 970-739-0596
- TruGreen Lawn Care 970-245-4404
- Western Slope Pest Control 970-216-7384
- WD Yard Inc. 970-243-1229
Colorado State University Extension Information
Educational support is being provided by Colorado State University Extension Services.
- Tri-River Area Colorado State University Extension
- Japanese Beetle Fact Sheet from Colorado State University Extension
Interested in more information? Subscribe to the Mesa County Agricultural Updates
By using traps with a pheromone lure that attracts adults, we can determine where our treatments will be most effective and provide valuable data about how the Japanese Beetle populations are changing over time. Trapping and monitoring are being provided by the Colorado Department of Agriculture. A robust network of traps allows us to make informed decisions about future eradication efforts.
Are you interested in helping us determine the effectiveness of our treatments? Homeowners can consent to have a monitoring trap placed on their property by emailing the Noxious Weed and Pest Management department at jb@mesacounty.us.
Please note: Traps will be placed where they are needed to collect monitoring data, so every property may not receive a trap.
Japanese beetle (Popillia japonica) was discovered in Grand Junction in 2022. Mesa County declared Japanese beetle a public nuisance in March 2023. Mesa County and the City of Grand Junction have embarked on a program to eradicate the beetle from Mesa County. This information is intended to help property owners participate in eradication efforts. Japanese beetle is an exotic invasive insect that feeds on over 300 plants, including turfgrass. Both the immature form (a grub) and the adult (a beetle) feed on plants and cause damage.
Adult beetles feed on leaves and fruit of hundreds of species, including fruit trees, ornamental and shade trees, vines, and field and vegetable crops. Larvae feed on the roots of irrigated turf and can be one of the many causes of brown spots in a lawn.
The goal of activities related to Japanese beetles is to eradicate Japanese beetles from Mesa County.
Identification
If you suspect you have Japanese beetle, adults or larvae, please bring a sample to the CSU Extension office located within the Mesa County Fairgrounds, 2775 US 50, Grand Junction; 970-244-1834. Place insects in a hard sided container. CSU Extension staff will identify the sample for you.
Adult beetles
Immature (larvae)
Immature Japanese beetles (larvae) are white grubs that often form a “C-shape.” There are lots of larvae that look like this, including various native beetle larvae. It is difficult to tell them apart. Professionals identify grubs like Japanese beetle by looking at the patterns of hair on
the hind part of the abdomen.
What to do
If you live in Mesa County:
- Mesa County and CSU Extension Tri-River Area recommend treating irrigated turf to kill grubs. This is especially important if you live near the area where beetles have already been detected. It is strongly recommended that those within 5-6 miles of this area treat any irrigated turfgrass.
If you live in Grand Junction in the delineated Japanese beetle area:
- Mesa County will pay to treat your lawn if you live in or near the hot zone to help eradicate the beetle. Find out more information on treatments at the Mesa County Noxious Weed and Pest website by clicking here.
Treatment recommendations
Mesa County and CSU Extension Tri-River Area are recommending insecticides with the active ingredient chlorantraniliprole to manage larvae of Japanese beetle in turfgrass. Insecticides with this active ingredient have long persistence and very low hazard to humans, pets, and bees.
- Scotts® GrubEx® is available for purchase without a pesticide license and may be used on residential lawns
- once per year.
- Acelepryn is a product available only to licensed pesticide applicators.
FOLLOW ALL LABEL INSTRUCTIONS.
Mow grass immediately before treating. Apply to dry lawn. Aerating lawns prior will not impact treatment negatively, and it may even help the chemical reach the root zone. Irrigate turf immediately after application to move the product into the soil. Do not over-irrigate, Lawn watering guide.
FAQs on treatment:
Q: How will treatment affect pollinators?
A: In turfgrass sites that are ONLY grass, there are no flowers that would attract pollinators. In these situations there is essentially no hazard to pollinators no matter what insecticide is used for grub control. However, potential problems can occur if there are flowering plants (dandelions, white clover, etc.) that are attractive to and visited by bees.
In lawn areas where pollinator attractive flowering plants are present, the risk from an insecticide application can be greatly reduced if the lawn is mowed before application, removing the blossoms. No insecticides should ever be applied to any plants that are flowering and attracting pollinating insects.
The type of insecticide being applied also greatly affects the potential risk to pollinators. Chlorantraniliprole, Bacillus thuringiensis var. galleriae, and insect parasitic nematodes are grub treatments that have very little, if any, hazard to pollinators when applied to turfgrass.
(Adapted from Whitney Cranshaw)
Q: What about “drying down” my lawn to kill grubs?
A: Withholding water from turfgrass is an option, but is not recommended. The effect will be limited if we receive rainfall. It also kills the turf. If you have trees in your yard, they will continue to need water out to their dripline, which will limit the areas you can “dry down.”
Q: What about using Milky Spore?
A: Milky Spore is not effective in Colorado. Our climate is too dry.
Q: Can I trap beetles as a non-chemical management option?
A: No. Traps are effective for monitoring, but are not an effective tool to reduce numbers of Japanese beetles.
For detailed information about Japanese beetle and treatment, please see the CSU Extension factsheet on Japanese Beetles 5.601.
Prepared by Mollie Freilicher, Melissa Schreiner, and Melissa Franklin of Colorado State University Extension Tri-River Area. 03/2023
Colorado State University Extension is an equal opportunity provider. Colorado State University does not discriminate on the basis of disability and is committed to providing reasonable accommodations. CSU’s Office of Engagement and Extension ensures meaningful access and equal opportunities to participate to individuals whose first language is not English.
Colorado State University Extension es un proveedor que ofrece igualdad de oportunidades. Colorado State University no discrimina por motivos de discapacidad y se compromete a proporcionar adaptaciones razonables. Office of Engagement and Extension de CSU garantiza acceso significativo e igualdad de oportunidades para participar a las personas quienes su primer idioma no es el inglés. Col.st/ll0t3
Mesa County will fund grub control treatments, which will be conducted by licensed and registered commercial applicators. Property owners in affected areas will receive an informational letter and consent form to authorize treatment on their property. Treatments will be applied in early spring (April–June) with follow-ups in August and September. Public parks in both the City and County will also be treated.
Frequently asked questions
- The Japanese Beetle is an invasive insect that causes over $460,000,000 worth of damages per year in eastern states.
- It feeds on over 300 species of desirable plants including grapes, peaches, roses, apples, sweet corn, trees, and turf grass.
- This pest is well established east of the Rocky Mountains which are a natural barrier to their spread.
- It is not established in the western states, and its movement is regulated by state and federal quarantines which prohibit the movement of infested plant materials to unaffected areas.
- When populations are discovered in western states they must be eradicated to prevent further establishment.
Images and detailed information about Japanese Beetle biology can be found on the “identification” page.
- Mesa County has secured initial funding to complete grub control treatments on all irrigated turf in the infested area.
- We will be seeking property owner consent to treat their lawns and eradicate Japanese Beetles in the grub stage.
- We are working with CSU Extension and the Colorado Department of Agriculture to promote awareness and expand opportunities for eradication efforts.
- This will be a multi-year effort.
- Mesa County will work with our partners to expand management options for homeowners.
In short, everyone in Mesa County!
- The Japanese Beetle feeds on a wide variety of plants that improve our lives. The spread of this beetle will affect everybody, whether you're growing 100 acres of peaches or have a small lawn and a rosebush.
- Japanese Beetles will damage or kill irrigated turf in lawns, parks, and golf courses as a grub.
- Property owners will see damage to turf from April-October.
- The adult beetles emerge and feed on many desirable ornamental and agricultural plants throughout the summer months.
- Adult beetles will destroy vegetable gardens, ornamental plants, and trees.
- Fruit growers will experience crop losses and increased production costs due to Japanese Beetle damage.
- We want to eradicate the Japanese Beetle to protect our economy and the quality of life for our residents.
- If this beetle spreads to our fruit growers it will decimate the agricultural production of Mesa County.
- This industry is one of the primary drivers of our economy.
- Such a large impact to fruit and wine production will have secondary effects on our tourism, plant exports, and retail industries.
- Japanese Beetles will impact residents by destroying lawns, gardens, and trees on landscaped properties.
- Additionally, they swarm and feed in groups on desirable plants. In this regard they can be a very unpleasant pest to have on your property.
If you are experiencing damage to turf and ornamental plants this season and find adult Japanese Beetles, please contact CSU extension services to confirm the identification.
- Acelepryn is a reduced risk pesticide that provides long lasting grub control when applied from April-June.
- When it is applied correctly, it is considered safe to use around humans, pets, birds, bees, and other pollinators.
