Chris Ulrey, a plant ecologist with the National Park Service, said the combined approach of using chemicals and natural predators to attack the adelgids have proven successful on a limited scale, but it's unlikely that enough resources can be mustered to beat back the threat in time to save the hemlocks.
Mother Nature is also not providing much assistance to adelgid opponents, since the dry and warm weather has helped the adelgids spread and thrive.
The National Park Service
recently approved the Finding of No Significant Impact (FONSI) for the Hemlock Woolly Adelgid Control Strategies along the Blue Ridge Parkway.
The FONSI has determined that there will be no significant environmental impacts that would occur by implementing a combination of chemical and biological controls to treat individual hemlock sites throughout the park.
said, "There's not a whole lot new.
agreed that the combination had shown visible results, and the chemical treatments had shown an effectiveness cycle of about three years.
said that means different predators will have to be brought into the same areas to help vanquish the adelgids.
said while the red tape is wrapped up, the footwork will be ongoing, and because of the intensity of the battle, the park service is selecting areas where the remaining trees appear to be the healthiest.
"It was a fairly dry spring, so spraying wasn't as effective as it might have been," Ulrey
"We may find that we have to spray those trees again.
Usually, the adelgid population builds until the tree is stressed.
When it's dry, and then having insects suck the sap, a lot of trees are dying out."
In Watauga County
, the park service is focusing on stands of hemlock near Simms Pond and around the Cone Manor Estate.
"They are looking pretty rough and we're not sure we can save them," Ulrey
"Some near Camp Catawba look okay still, and we hope to target more out near the Cone Estate next year."
said those that have been chemically treated were marked with a dot, but he
said that was unnecessary since the treated trees are so much obviously healthier than their infested counterparts.
The weather has also not helped contain the adelgids, because the recent winters have been warm.
said in northeastern areas, the adelgid has reached a natural upper limit to its territory because of low temperatures.
"An unusually cold winter might help," he
"The adelgids can't tolerate real low temperatures."
Because it's now basically a losing battle, Ulrey
and other biologists hope to maintain the trees they"ve already been protecting and treating, while simultaneously trying to bring new beetles and other natural predators into the mix.
"We only treat those that are still alive, but it will never be enough," Ulrey