Typical ash tree locations, plus color enhancements—Providence Road. (Images by City of Oak Ridge)

A pest known as the emerald ash borer could kill most ash trees in Oak Ridge, and the cost to treat or remove the trees that pose a threat to the city’s electric system has been estimated at $662,000, officials said.

The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients.

The City of Oak Ridge said in May that ash trees in Oak Ridge are dead or dying due to the emerald ash borer. Once compromised by the beetle, the city said then, the trees pose a significant hazard to people, property, and power lines.

“The impact of this pest is extreme,” Oak Ridge Electric Director Jack L. Suggs said in a June 27 memo to City Manager Mark Watson. “We expect virtually 100 percent death of all ash trees in the city, with only trees receiving ongoing chemical treatment surviving. Many of these trees will impact our power lines, in addition to other public facilities such as parks and streets.”

A survey of the city’s electric power lines with help from University of Tennessee forestry interns this summer is evaluating the health of the trees and the probability that they might affect the electric system. The work is only about one-third complete, but officials estimate there could be about 1,000 to 1,200 trees that will need to be either treated or removed because of their potential to affect the city’s electric system, Suggs said. [Read more…]