North Dakota Confronts Invasive Emerald Ash Borer

In partnership with: North Dakota Department of Agriculture

The emerald ash borer is visually stunning, with a shimmery green body reminiscent of the gemstone it’s named for. But this tiny beetle is an ash tree killer, and it has made its way to North Dakota.

This invasive pest, native to northeastern Asia, was first found in LaMoure County in August 2024. The species targets ash trees, boring into the bark and eating the conductive tissue inside. While they only recently arrived in North Dakota, they’ve killed hundreds of millions of ash trees across the country.

“Ash trees currently make up the majority of North Dakota’s forest cover, whether it’s urban forests or riparian forests or shelter belts along fields,” says Charles Elhard, North Dakota Department of Agriculture plant protection officer, who adds that ash is one of the state’s few native trees. “So that’s why we are concerned about it.”

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Save the Trees

The infestation in LaMoure County caused significant dieback, but the beetles have not been detected anywhere else in the state. However, it’s just a matter of time, says Joe Zeleznik, a North Dakota State University Extension forester.

“It’s a slow threat, but it’s still a threat,” Zeleznik says. “It’s a big threat in that it will get here. The cold winter temperatures will not save us from emerald ash borers. Those cold winter temperatures may slow it down, but they’re not going to stop it completely.”

According to Elhard, each time an infestation is found, NDDA can enact a quarantine of the affected area. Pesticide treatments may also be used to prevent the beetles from infesting more trees.

“The thing to do is plant many different species. So if another pest moves in, you’re not going to wipe out a significant number of trees.”

– Charles Elhard, North Dakota Department of Agriculture

There are also important steps everyday people can take to slow the spread, most notably avoiding moving firewood.

“People might take infested firewood and carry it a long, long distance,” Zeleznik says. “We’re wondering if that’s how it got to North Dakota in the first place.”

Better options include buying local or certified heat-treated firewood.

Meanwhile, Elhard and Zeleznik agree that North Dakotans should diversify tree plantings to help protect from pests that specialize in one species. That could mean adding some new varieties to your farm’s windbreak or even in your backyard.

“The thing to do is plant many different species,” Elhard says. “So if another pest moves in, you’re not going to wipe out a significant number of trees.”