EMERALD ASH BORER CONFIRMED IN LEE COUNTY, IOWA

Written by Theresa Rose on July 8, 2015

DES MOINES – A highly destructive insect of ash trees has been confirmed in Fort Madison, bringing the number of confirmed counties in Iowa to twenty-six, making Lee County its latest victim. Emerald ash borer (EAB) is a small, metallic-green beetle that is responsible for killing tens of millions of ash trees in 25 states. Native to Asia, EAB was first discovered in the U.S. in Michigan in 2002 and Iowa in 2010.

The larvae stage of this wood-boring insect burrow under the bark of ash trees, disrupting the flow of water and nutrients, ultimately causing the tree to die. EAB infested ash trees include thinning or dying branches in the top of a tree, evidence of woodpecker activity, S-shaped feeding galleries under dead or splitting bark, D-shaped exit holes, and water sprouts.

“The Fort Madison discovery is the fourth city in Iowa along the Mississippi River where EAB has been detected since last year said Mike Kintner, Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator.

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 Plant Health Inspection Service and the USDA Forest Service.

Since larvae of EAB can unknowingly be transported under the bark of a tree, the Iowa EAB Team strongly cautions Iowans not to transport firewood across county or state lines. The movement of firewood throughout Iowa or to other states poses the greatest threat to quickly spread EAB and other plant pests. A statewide quarantine remains in place, 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.

At this calendar date, the treatment window for soil-applied preventive treatment measures (soil injection, soil drench, or granular application) and basal trunk sprays has ended. Trunk injection remains a viable EAB management option, as this method can be done when the tree has a full canopy of leaves (now through August), provided there is good ground moisture. 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, and treat during the recommended treatment time.

Please contact Iowa EAB Team members to have suspicious looking trees checked in counties not currently known to be infested. The State of Iowa will continue to track the movement of EAB on a county-by-county basis. Before a county can be officially recognized as infested, proof of a reproducing population is needed and an EAB must be collected and verified by USDA entomologists.