Ash Borer Infestation Jumps South in National Park
Shenandoah National Park staff have confirmed additional infestations of emerald ash borers (EAB) in the park. The ash tree-killing pest is now found roughly as far south as Swift Run Gap (Rt. 33). Last year, adult EAB beetles were only known to be at the north end of the park in Warren County and near park headquarters in Page County.
Beetles have been caught in surveillance traps near Mathews Arm Campground, Gravel Springs Hut, Pinnacles Picnic Area, Big Meadows Picnic Area, and South River Picnic Area. They represent detections in three new counties: Rappahannock, Rockingham, and Madison.
Park Superintendent Jim Northup called the spread of the beetle “a significant jump.”
The emerald ash borer is a half-inch-long metallic green beetle that lays eggs on the bark of ash trees. After hatching, the larvae burrow under the bark and create feeding tunnels that cut off nutrient and water flow to the tree. Trees typically die within three to five years. If EAB becomes established in Shenandoah, it could lead to upwards of 95 percent ash mortality.
Five percent of the trees in the park are ash and they occur in 16 of its 34 vegetation communities. Collectively, these ash-containing communities make up 65 percent of the Park’s forest (126,883 acres).
EAB was accidentally introduced to North America from Asia and was first discovered in southeast Michigan in 2002 on infested wood packaging material. Since its introduction, EAB has spread to 25 states and two Canadian provinces, and is believed to have killed more than 50 million ash trees.
Since the EAB is a non-native pest, the Park is mandated to minimize its impacts on native ash trees. In April 2013, the park began conducting preventive EAB pesticide treatments on ash in developed areas and select sensitive plant communities in the northern third of the Park. Treatments now include portions of the Central District. Complete eradication of EAB is not currently feasible. The park’s goals are to reduce hazard ash tree formation in developed areas and to preserve a portion of the park’s trees until approved biological controls become available.
EAB and other exotic forest pests can be transported via firewood. To minimize this pathway, park regulations only allow heat-treated firewood (USDA approved) and firewood that is collected within the park.