Emerald Ash Borer Confirmed in Decatur County

New detection of invasive pest discovered in rural Decatur County

November 9, 2017, 8:46 am | Dustin Vande Hoef, Julie Tack, Laura Sternweis

Emerald Ash BorerDES MOINES, Iowa – A highly destructive beetle that targets and kills ash trees, the emerald ash borer has been confirmed in Decatur County. Native to Asia, EAB is responsible for killing tens of millions of ash trees in the U.S.

This finding occurred in a rural area north of Grand River as a result of someone with a tree service recognizing potentially EAB-infested ash trees. After contacting the Iowa Department of Agriculture and Land Stewardship, the site was visited and later confirmed positive following the diagnosis of an insect specimen.

EAB was first discovered in Iowa in 2010 and continues to be found in new areas. There are now 53 counties in Iowa confirmed with the presence of EAB. Like other parts of the U.S., much of the pest’s spread into new areas can be attributed to this insect hitchhiking on firewood. The Iowa EAB Team strongly urges Iowans to use locally sourced firewood, burning it in the same county where it was purchased.  

“This find is noteworthy in the fact that it makes it the 14th county in Iowa this calendar year to be confirmed with EAB,” said Mike Kintner, Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator. “This surpasses the previous highest finds of 13 counties back in 2014. The Decatur County finding is an excellent reminder that EAB can still be found in the dormant season. Woodpecker damage to an ash tree could be an indicator of EAB activity in that tree.”  

EAB-infested ash trees can include branch dieback in the upper crown, water sprouts along the trunk and main branches, vertical bark splits, D-shaped emergence holes and S-shaped tunneling under loose bark as well as woodpecker damage. Early detection is difficult to identify in newly infested trees.
The Iowa EAB Team provides EAB diagnostic assistance to landowners and includes officials from Iowa Department of Agriculture and Land Stewardship, Iowa State University Extension and Outreach, the Iowa Department of Natural Resources, USDA Animal and Plant Health Inspection Service and the USDA Forest Service.

At this calendar date, the window for all preventive treatments has closed. If a landowner is interested in protecting a valuable and healthy ash tree within 15 miles of a known infestation, he or she should have landscape and tree service companies bid on work, review the bids this winter, and treat beginning spring 2018 (early April to mid-May). More details pertaining to treatment are available in Iowa State University Extension and Outreach publication PM2084: https://store.extension.iastate.edu/product/13114

To learn more about EAB and view maps of its distribution, please visit www.IowaTreePests.com.

About the Authors: 

Julie Tack

Iowa Department of Natural Resources