Tipton County Extension Master Gardeners


 

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Emerald Ash Borer (EAB) Update


  • 41 counties in Tennessee are now under state/federal quarantine.
  • EAB cannot be contained, and all ash species are at risk of dying.
  • Significant ash trees can sometimes be saved with permanent chemical treatments, if detected early. 
  • The most important way to slow the spread of EAB is to stop moving firewood.


EAB adults fly from April until September, dispersing one-half to three miles from the host tree.  Tennessee does not have large populations of ash trees like other states, but this pest is still causing problems.  The larvae live and tunnel under the bark cutting off water and nutrients to the tree.  When larvae emerge in the spring, they leave D shaped exit holes in the bark. 

The greatest threat to the spread of EAB and other pests is moving firewood.  Tennessee is one of 33 states and Canada that have restrictions on moving firewood because of the potential insects that can be present in the wood. 

Trees infested with EAB begin to thin as water and nutrients are cut-off by larvae tunneling.  Large sections of the tree then die.  It takes two to four years from first being detected in a tree until the tree dies. 

Native ash trees have little to no resistance to EAB and natural enemies, so far, have had an insignificant effect in controlling this pest. Because both larvae and adults feed on the ash tree, a combination of systemic chemicals like Imidacloprid and Dinotefuran and timely foliar sprays of Permethrin when adults are actively feeding have provided the best control.   For more information please call the Tipton County Extension office at 901-476-0231.