ASHLAND – An insect that threatens an abundant American tree has been discovered at a nearby state park.
Officials from Nebraska Game and Parks announced June 26 that the emerald ash borer had been found at Mahoney State Park near Ashland.
The discovery was made 20 days earlier by Nebraska Department of Agriculture (NDA) staff in a baited trap at the park’s Lakeside Campground. The announcement was made after the identification was confirmed.
The emerald ash borer is a highly invasive insect that was first detected in Michigan in 2002. Since then it has killed millions of trees in the U.S.
The insect’s presence was confirmed in Missouri six years ago, in Iowa in 2010 and in Kansas two years later. Nebraska was the 27th state to find the beetle within its borders.
The emerald ash borer was first discovered in Nebraska in June 2016 in Omaha and a few days later in Greenwood. The confirmation of the insect’s presence at Mahoney is the fourth in the state.
The half-inch long, slender metallic green beetle came from Asia. After adult females lay eggs in the bark, the larvae bores tunnels under the bark, according to Sarah Browning, a University of Nebraska Extension educator in Lincoln. The tunnels disrupt the tree’s ability to transport water and nutrients.
There are more than eight billion ash trees in the United States, according to the website americanforests.org. The trees were popular in landscapes and along roadways across the country.
The NDA placed survey traps at Mahoney and several other places around the state about 10 years ago when department officials, along with Game and Parks, the Nebraska Forest Service and the U.S.D.A’s Animal and Plant Health Inspection Service, began to suspect the insect was in the state.
Mahoney State Park Superintendent Jake Rodiek said they have no idea how many ash trees exist in the forested areas of the park, but in the landscaped areas several hundred were planted when the park was being built in the early 1990s.
“A lot of ash trees were planted in the original design in the manicured areas,” he said.
Game and Parks has a plan in place to mitigate the emerald ash borer at Mahoney. Staff and equipment are on hand to treat trees that are infested, Rodiek said.
“From this point forward we will have treatment of selected ash trees that we’re wanting to keep,” he said.
Park officials do not plan to undertake an extensive removal of ash trees, but will remove those that become heavily damaged by the insects.
“If at some point it becomes a safety concern to visitors,” Rodiek said.
New trees have already been planted in anticipation of the emerald ash borer’s arrival. Rodiek said they have selected trees native to the region, including burr oak, white oak, maple and linden.
Planting different types of trees will help make sure an infestation like the emerald ash borer will not have such a devastating effect on the park’s tree population, Rodiek said.
“It’s a wide variety just to ensure we don’t have too many of the same type of trees in the same area,” he said.
Game and Parks has attempted to limit the spread of the emerald ash borer by instituting a voluntary firewood restriction program at all state parks in 2013.
“To be sure that nothing is being transported in and out of parks as much as possible,” Rodiek said.
The public must buy firewood within 50 miles of the park they are visiting. They can burn deadfall wood collected at the park. Game and Parks will exchange firewood for people who brought wood from other states for free at 10 major parks and recreation areas.
Despite the firewood ban, Game and Parks officials were certain the emerald ash borer would find its way to Nebraska’s state parks sooner or later.
“We knew eventually the beetles would start heading in this direction,” Rodiek said.
For the next several years the traps will stay in the ash trees at Mahoney to monitor the insect, Rodiek said. They are triangular shaped purple-colored traps that hang in the branches and can easily be seen by visitors.
The Nebraska Forest Service recommends treatment of ash trees within 15 miles of the site where the emerald ash borer was detected and only if the trees are in good health and in a key location in the landscape.
Symptoms of infestation include canopy thinning, branch die-back or D-shaped exit holes in the bark. The forest service recommends a certified arborist examine the tree.
For more information on the emerald ash borer, go to eabne.info.