Japanese Beetle Eradication

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

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

Japanese Beetle Trap Status Map

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.  

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.

How you can help:

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:

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.

Learn how to apply grub control granules

• 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.