Emerald Ash Borer Could Cost Tennessee Billions

Posted at 11:09 PM, Jun 06, 2017
and last updated 2017-06-07 00:09:36-04

Ad invasive species of bug is expected to become prominent in the next few years in Davidson County and it could cost billions statewide.

The emerald ash borer is a tiny green beetle that is ravaging ash trees across America and has made it's way to Tennessee, and is expected to spread in Davidson county. The bug originated in china and has no natural predators locally. It has spread through the eastern half of Tennessee and is impossible to stop unless treated, according to people with the Tennessee Division of Forestry.

"Now that it's here, it's kind of given free reign to set up shop and establish populations as it marches east to west in our state," said Tim Phelps, forestry communications and outreach unit leader. "We discovered it first in Knoxville in 2010, it's in 59 counties including Davidson and Williamston."

The parasite burrows into an ash tree and moves around under the bark, feeding on the tree's trunk. Eventually those lines wrap around the tree, strangling it and causing it to die. The bugs lay their eggs, which hatch and fly to other trees, leaving behind a signature 'D' shaped hole on the host tree. The cycle then starts over.

"The thing about Emerald Ash borer is that it starts in the canopy of the tree and goes top down, feeding down and slowly girdles the tree," said forester Nathan Hoover. Hoover works in forest health and has been looking for infested trees in the county. None have been found yet, but foresters caught live beetles in a trap set in the county in 2014. That means while there are likely trees in the county that are infested, foresters have not yet located them.

Forestry officials said there's a high probability trees are infected and want residents to be aware of the signs. Infestations may not be detectable up to three years, but foresters suggest residents with ash trees consider treating or removing them now. Typically, removing an ash tree costs between $500-1000. Treating one can take many years and can cost as much as removal, though that cost is spread out.

Also, moving the trees can cause problems, according to Phelps.

"We're in a quarantined county. You can move it between quarantined counties," he said. "Basically, you can create a new infestation by moving it outside of the county."