ASHEVILLE (AP) — An entomologist with the U.S. Forest Service says a beetle from Asia that is destroying ash trees across the country will arrive in western North Carolina in the next few years.
The Asheville Citizen-Times reports Paul Merten has spent nearly a decade chasing down the emerald ash borer. Merten and Haywood County Community College forestry student Caroline McGough went into the woods on the Appalachian Trail last week, unleashing tiny wasps that feed on the emerald ash borer.
Merten said the emerald ash borer was first discovered near Detroit in 2002. It was confirmed in July 2015 near the Tsali Recreation Area in the Nantahala National Forest. Evidence of the beetle was also found on private land along the French Broad River from Tennessee to Marshall.
Emerald ash borer damage is actually caused by the larvae.
The beetles lay their eggs in between layers of an ash tree’s bark. Larvae hatch in about a week and bore into the tree, feeding on the inner bark and phloem, the vascular tissue that transports nutrients to branches and leaves.
Their feeding creates “S” shaped tunnels, known as galleries. The larvae go through four feeding stages, which cuts off water supply and the flow of nutrients within the tree. They then go through the pupal stage in late spring. Adults begin to emerge in “D” shaped holes in May and June. The adults then go on to mate and feed on ash tree leaves, Merten said.
“We’ve been keeping a pretty good eye on ash trees,” said Kristine Johnson, supervisory forester with the Great Smoky Mountains National Park, where the beetles were first spotted on the Tennessee side of the half-million-acre park. “We haven’t seen mortality on North Carolina side yet.”
The Smokies are trying to get ahead of the EAB infestation by treating trees not yet infected, mostly in the Deep Creek and Chimneys picnic areas.
Using “Barney traps,” large purple traps that hang in ash trees with a scent believed to attract EABs, they hope to catch the beetles. If they find the insects, they use a systemic insecticide that is injected near the bottom of the tree trunk.
“Treatment is more effective when the tree is healthy, a pre-emptive treatment,” Johnson said.