Wausau Emerald Ash Borer

Emerald Ash Borer infections expected to skyrocket in Wausau

City forester John Kahon educates the city’s Parks and Recreation Committee Monday afternoon about Emerald Ash Borer, using an infected ash tree on Cherry Street as an example.

The Emerald Ash Borer situation in Wausau is expected to get worse over the coming years, city parks officials say. 

City Foresters have identified 12 more street trees that are infected, according to a report from the city’s forester. And more are expected as the tree-killing bug is now in the entire state of Wisconsin. 

Emerald Ash Borer is a bug that infests ash trees, killing them eventually. As those trees die, they become unstable and can fall on streets and on homes. 

That’s a problem for street trees because practice some time ago was to plant trees of one species on a block for uniformity reasons. That’s a problem now because Emerald Ash Borer could wipe out an entire block of ash trees. Foresters now plant a diversity of species to prevent against that happening in the future. 

Members of the city’s parks committee met Monday afternoon at an infected ash tree on Cherry Street on the city’s north side as City Forester John Kahon explained how to spot a tree that’s infested with Emerald Ash Borer. Missing bark on a tree is usually an indicator, as are the presence of a lot of woodpeckers who will attempt to peck out the EAB larvae to eat. 

Kahon says the department sprays a number of street trees and removes so many of them per year, but once infestation accelerates, there is a concern that more trees will need to be taken down than city staff can get to. 

Kahon says there are just a bit more than 4,000 ash trees left in boulevards; that’s down from about 6,600 before the bug made its way into the area.