Latest discovery marks 19 Kansas counties with the destructive beetle
By Pat Melgares, K-State Research and Extension news service
MANHATTAN, Kan. – The Kansas Forest Service has confirmed the presence of the emerald ash borer in Marshall County, the fourth Kansas county confirmed this year and 19th since the first discovery in Wyandotte County in 2012.
KFS officials said a live larva was collected from an EAB trap tree that had been installed earlier this year just north of Marysville, within the city’s local brush dump.
Forest Health Coordinator Shad Hufnagel said the state’s forest service “recognizes the importance of early detection and proactively installs trap (or detection) trees in strategic locations to help identify if local populations of the insect are present.”
He added that the trap trees are often placed adjacent to counties with known EAB infestations, in areas with a high density of ash trees, and in locations where brush and firewood are frequently moved. In 2025, 15 trap trees were installed covering 11 counties.
“One of the primary ways EAB moves into new areas is through the human movement of wood products such as brush and firewood,” Hufnagel said. “It’s possible that the insect has naturally dispersed into the area as it seeks new host trees, but it is also highly likely that it caught a free ride into the area on material from surrounding locations.”
Earlier in 2025, state officials confirmed the presence of the emerald ash borer in Linn, Pottawatomie and Bourbon Counties.
The emerald ash borer is an exotic, invasive beetle from eastern Russia and northeastern Asia that likely was brought to the U.S. in infested packing material. The beetle threatens urban and rural forests by killing North American ash species and their cultivars.
KFS officials note that at least 70 million ash trees have already been destroyed due to the emerald ash borer, and as many as 9 billion North American ash trees will eventually be functionally rooted out and destroyed from the continent.
The discovery in Marshall County makes 19 Kansas counties in which the emerald ash borer has been confirmed, including Wyandotte (2012), Johnson (2013), Leavenworth (2014), Douglas (2015), Jefferson (2015), Atchison (2016), Doniphan (2017), Shawnee (2017), Miami (2019), Jackson (2019), Brown (2022), Osage (2022), Franklin (2023), Lyon (2024), Nemaha (2024), Linn (2025), Pottawatomie (2025) and Bourbon (2025).
Forest officials say landowners should learn the signs and symptoms of emerald ash borer in their ash trees, including thinning canopies. As the feeding progresses, trees may begin to sucker (a process called epicormic sprouting) where branches appear near the trunk or lower canopy. Eventually, small D-shaped holes may appear in the bark.
According to Hufnagel, host trees will often decline over the course of a few years as the larval stage of the insects feed on the vascular tissue of the affected trees. Unfortunately, early infestations are often difficult to identify.
Landowners are encouraged to create a replacement plan for the ash trees on their property to ensure a continually healthy canopy as ash trees decline. A landscape with many types of trees is more resilient to insect, disease and environmental threats that exist or could occur in the future.
In some cases, chemically treating some high-quality ash tree specimens might be a viable management option.
“There are different management and mitigation strategies that can be employed when dealing with infestations of EAB including tree removal, chemical protection, and simply waiting for mass mortality,” Hufnagel said. “It is important to note, however, that infested ash trees will decline and eventually die. Along with that comes heightened concern for those trees becoming hazardous.”
Those seeking treatment or removal of ash trees in a county where the insect has already been detected should consult an arborist. A listing of certified arborists in Kansas is available online.
Landowners, especially those in counties where the insect has not been detected, are encouraged to report suspected cases of emerald ash borer to the Kansas Department of Agriculture, or to the Kansas Forest Service.
All Kansans are reminded of the recommendation to avoid bringing firewood from another state or county where emerald ash borer has been previously detected. Use local sources for firewood.
The Kansas Forest Service, in partnership with K-State Extension, continues to offer workshops and educational training in counties with detected populations of emerald ash borer, as well as those communities not yet affected by the pest.
In addition, KFS has recently added numerous EAB-related video presentations on their YouTube Channel, http://www.youtube.com/@KansasForestService
More information on resources for treatment of infected trees is available online from the Kansas Forest Service.
