A new emerald ash borer (EAB) infestation has been discovered in Douglas County, this time in the town of Highland. The find brings the number of affected towns in the county to three.
EAB was initially detected in the city of Superior in 2013 and led to the preemptive removal of 3,000 public ash trees.
In August 2017, one of the metallic green insects was found on a trap in Amnicon Falls State Park.
"We haven't seen an infestation there," said Paul Cigan, a regional forest health specialist with the Wisconsin Department of Natural Resources, but it's a sign that beetles are in the town of Amnicon.
The Highland infestation was found by a utility tree crew, which reported white ash with heavy woodpecker damage in the Beauregard Lake area. Cigan said it appears the infestation is relatively new, about four years old.
Surrounding black ash do not currently display signs or symptoms of EAB, he said. Based on its natural rate of spread, however, there is likely to be a low-density population of the beetles for about 15 miles around the infested tree.
"EAB is often lingering in an area years before we find it," Cigan said, and infected trees can take five years to die.
He encouraged all Douglas County residents to become familiar with EAB signs and symptoms and to report possible infestations to their local DNR Forestry office.
"With three detections in Douglas County, there's no question it's more widespread," Cigan said.
Woodpeckers, in particular, are good detectors of EAB. Property owners can best see the woodpecker damage, sometimes called "flecking," from January until trees leaf out in the spring.
EAB has been found in all of the counties in the southern half of the state and seven northern counties, including Douglas. In March 2018, all of Wisconsin was put on quarantine for EAB.
One of the biggest factors in the spread of the beetles is infected firewood. State fire rules prohibit bringing firewood into any state property, including parks, from more than 10 miles away. Firewood used in federal forests must come from 25 miles away or closer. No firewood is allowed to move out of state because of the statewide quarantine.
EAB can't be stopped, but it can be managed.
Foresters are available to help residents who own woodlands of 10 acres or more develop a management plan for their land that will reduce the impacts of EAB. That can include harvesting ash trees before they're destroyed and planting non-ash seedlings to keep brush, invasives and understory plants from taking over the area.
Some ash trees can be saved, as well. Cigan said treatments, particularly an injection option, are quite effective at protecting them from EAB. Treatments need to be reapplied every two or three years, so property owners should consider first if the tree is worth treating.
Visit the University of Wisconsin-Extension's EAB site, labs.russell.wisc.edu/eab, for more information on EAB signs, symptoms and treatment options.
To schedule a woodland walk-through or report a possible EAB infestation, contact Cigan at 715-416-4920 or paul.ciganMark Braasch in Gordon, 715-376-2299, firstname.lastname@example.org; Blake Johnson in Superior, 715-817-8423, email@example.com; and Zachary Neitzel in Brule, 715-296-0641, firstname.lastname@example.org.