Officials with the U.S. Department of Agriculture have confirmed a population of emerald ash borers in Wagoner County. State foresters first announced they were investigating the insect’s presence in the area on April 21.
Emerald ash borers are small beetles responsible for destroying hundreds of millions of native ash trees by boring into their bark and feeding on nutrients.
Oklahoma’s ash trees are mainly found around lakes, including those in state parks.
The beetles can fly up to 10 miles each year, but they primarily hitch rides on firewood. Forestry officials are urging Oklahomans to avoid traveling with wood and instead burn it where they buy it.
The emerald ash borer, native to northeastern Asia, was first found in North America in 2002 and has killed off large populations of ash trees in eastern states. Wagoner County joins Carter, Choctaw, Delaware, Love, McCurtain, Murray and Pushmataha counties with confirmed cases.
A thinning canopy, branch dieback and D-shaped exit holes are markers of the destructive beetle.
The bugs have no significant predators in the U.S. aside from woodpeckers, which usually only reach the larvae once a population has grown and the tree is dead. Last year, Oklahoma foresters began releasing parasitoid wasps to help limit the beetle’s spread.
The wasps inject their eggs into emerald ash borer eggs, which they find on the bark of ash trees. Instead of producing an emerald ash borer larva, the host egg will hatch a new wasp.
More than 30 states with emerald ash borer populations have released the wasps as of 2024. But it’s too early to tell if the biological control is working in Oklahoma.
Dieter Rudolph, forest health specialist for Oklahoma Forestry Services, told StateImpact on April 9 the agency will assess the program’s performance next year.
“If we find these parasitoids in 2027 we will know they have successfully parasitized EAB,” Rudolph wrote in an email. “If we don’t find any after a couple rounds of trapping for wasps we can assume they were not successful.”
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