10/17/2026
For those waiting to cut down ash trees or prune them, the time to do so has now arrived. Emerald ash borer (EAB) larvae mature into adults inside ash trees and emerge starting in late spring. They soon mate. Females then find an ash tree to lay their eggs on. By October, almost all the adults have died. Their offspring will spend the winter chewing galleries under the bark. Over time, thousands of EAB larvae create so many galleries under the bark that eventually water and nutrients to the host tree are cut off, killing it.
“Best management practice is to wait until the adults have died before disturbing the canopy of an ash tree to avoid sending EAB adults flying to other trees,” says ODF EAB Support Specialist Matt Mills. “From October until early April one can safely remove or prune any ash tree. Once a tree is down, we want to act to limit the spread of EAB to new areas. Burning and chipping on site are good ways to kill beetles. Creating firewood is another option, but remember that EAB can spread inside firewood that is not heat treated properly. Untreated wood should be moved as little as possible, and never more than 10 miles from where it was harvested, to limit the spread of any wood-boring larvae inside."
