If you own an ash tree and you begin to see the canopy dying or the bark being torn up, it may be more than just a regular tree issue, it may be a specific parasite: the emerald ash borer beetle.
An invasive species from Asia, the beetle arrived in the United States in the 1990s and in Douglas County in 2016. These beetles are roughly 1" long, and have a blue-green back.
As of 2025, they have been reported in all 99 counties in Iowa, and 15 counties in Nebraska. They are slowly moving west across the Cornhusker State, and killing trees in the process.
UNL Extension employee Julia Cambridge describes the process of how the beetle kills the tree, “The adult beetle lays its eggs under the bark… as the larvae hatches, it eats under the layers, causing damage and disrupting the flow of sugar and nutrients from the tree.”
The Nebraska Forest Service says one way it spreads is through human transport of infested firewood. To prevent the spread, it is recommended to purchase firewood where you will burn it.
If you spot a beetle, UNL Extension recommends filing a report with the Nebraska Forest Service. If you think your ash tree is infested with the beetles, contact an arborist to come examine it.
If you have a smaller ash tree within 15 miles of a reported sighting, you can get treatment to hopefully prevent the spread. Check with the Nebraska Forest Service on what steps you can take to either prevent the tree from dying, or to replace them.
