The North Carolina Department of Agriculture implemented a statewide emerald ash borer (EAB) quarantine effective September 2015. The quarantine prohibits moving pieces of hardwood shorter than four feet out of state into non-quarantined areas. The restriction only applies to hardwoods—deciduous trees—because the EAB does not attack conifers—needle-bearing evergreens. The “less than four feet” restriction eliminates lumber, which is unlikely to carry live EAB eggs or larvae after the milled wood is kiln dried. But it does apply to firewood, removed trees, and tree debris.
How the EAB quarantine affects gardeners and campers
The emerald ash borer is an Asian wood-boring beetle that accidentally arrived in North America, first showing up in Michigan and Ontario in 2002. It’s been gradually expanding its territory and by 2013 arrived in North Carolina. Although the beetles can fly from tree to tree, the movement of firewood is the leading accomplice in moving the EAB larvae from place to place. To reduce the risk of infesting our trees, the message to us on the EAB is “Don’t move firewood around. Burn it where it grew.”
Fringe trees are at greatest risk
Four ash species are native to North Carolina, but most are found in the eastern part of the state. Green (Fraxinus pennsylvanica), white (Fraxinus Americana), Carolina (Fraxinus caroliniana), and pumpkin (Fraxinus profunda) ashes are occasionally found here in the mountains, but the greatest threat from the EAB is to the American fringe tree (Chionanthus virginicus), a close relative.
Signs of EAB infestation
Unfortunately, an EAB attack is very difficult to identify. Eggs are laid on the bark and the larvae make a small, 1/8-inch, D-shaped entry hole that is hard to see on the rough bark. By the time the adults emerge, the damage is done. Dieback starts in the upper branches and death of the tree typically occurs after two or three years.
What you can do
Although there is systemic insecticide available, our best hope is to slow the advance of the EAB to allow development of an effective protective measure. Gardeners should watch fringe trees and ashes for signs of infestation. Avoid planting these trees in your landscape until more is understood about the EAB threat.
Campers and picnickers, don’t bring firewood home!
Burn that wood where it grew.
Article written by Glenn Palmer, Extension Master Gardener Volunteer.
For help identifying ash and fringe trees, visit these websites:
https://www.cals.ncsu.edu/plantbiology/ncsc/tnc/fraxinus.htm
https://plants.ces.ncsu.edu/plants/all/chionanthus-virginicus