Emerald Ash Borer confirmed in Black Hawk County, intrastate quarantine enacted
By Jean Caspers-Simmet
Date Modified: 02/24/2014 11:23 PM
WATERLOO — Emerald Ash Borer has been identified in a tree in Waterloo. It is the the sixth county where the invasive beetle has been found in Iowa.
"EAB kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America," said Robin Pruisner, state entomologist with the Iowa Department of Agriculture and Land Stewardship at a press conference in the Cedar Valley Sportsplex in Waterloo.
The current EAB infestation was found Jan. 24 by city employees performing routine trimming, said Todd Derifield, Waterloo city forester. With the assistance of the Iowa EAB Team, additional trees were found to be infested in a 10 square block area on the northeast side of Waterloo, east of Highway 63, south of Gates Park, north of Cottage Street and west of Linden Street.
The larvae were positively identified as EAB by federal identifiers at the Smithsonian Institution.
A statewide quarantine restricting the movement of hardwood firewood, ash logs, wood chips and ash tree nursery stock out of Iowa into non-quarantined areas of other states was issued last week.
"The Iowa EAB Team determined that a whole-state approach to the quarantine is warranted," Pruisner said. "Communities need to focus on planning and implementing proactive measures to prepare for EAB in their urban forests."
EAB infestations were discovered in Allamakee County in May 2010, Des Moines County in July 2013, Jefferson County in August 2013, Cedar County in October 2013 and Union County in December 2013.
The EAB Team cautions Iowans not to transport firewood across county or state lines, Pruisner said. Most EAB infestations in the United States have been started by people unknowingly moving infested firewood, nursery plants or sawmill logs. The adult beetle also can fly short distances.
Ash is one of the most abundant native tree species in North America and has been heavily planted as a landscape tree in yards and other urban areas. According to the USDA Forest Service, Iowa has an estimated 55 million rural ash trees and approximately 3.1 million more in urban areas.
"Forestry Bureau staff with the Iowa Department of Natural Resources have completed 242 urban tree inventories in Iowa, in communities with less than 5,000 residents," said DNR State Forester Paul Tauke. Statewide, Iowa averages 16 percent to 17 percent ash on city property, though the ash component can get as high as 87 percent. We hope this latest infestation will motivate communities that have not taken an inventory of their forestry resources, to do so very soon."
Waterloo's urban forest includes 4,364 ash trees located on public properties in the city, Derifield said.
"We plan to remove the ash trees infested with Emerald Ash Borer on public properties and continue to reduce ash populations in the public areas," Derifield said. "This is a devastating blow to Waterloo's tree resources as we will be losing 17 percent of the trees on public property over the next few years.
There are 3 million acres of forest land in Iowa and ash would be about 40,000 to 50,000 acres of that, Tauke said.
"It tends to be a minor component of our forest stands."
He suggested landowners work with DNR district foresters.
"If they have enough ash on their property that are large enough, they might consider working with their forester to do a sale of ash," Tauke said.
Derifield and the other foresters said that when replanting trees, diversity is important.
"Plant the right tree in the right place," Derifield said. "If you plant three or four trees, plant three or four different varieties."
Preventive treatments next spring are available to protect healthy and valuable ash trees within 15 miles of a known infested area, said ISU Extension and Outreach Entomologist Mark Shour. For more details, see ISU Extension and Outreach publication PM2084, extension.iastate.edu/Publications/PM2084.pdf.
Tauke urged landowners to contact Iowa EAB Team members to have suspicious trees checked. The state will continue to track the movement of EAB on a county-by-county basis.