Tree-killing insect now confirmed in 27 counties in Iowa

Tree-killing insect now confirmed in 27 counties in Iowa

Emerald ash borer discovered in Montgomery County in southwest Iowa this week.

The emerald ash borer, a destructive and invasive insect of ash trees has been discovered in central rural Montgomery County. The discovery was announced by the Iowa Department of Agriculture this week. Iowa's growing number of counties with confirmed detections of EAB has now reached 27. Native to Asia, EAB has spread to 25 states since first being identified in Michigan back in 2002. This exotic pest is responsible for the death of tens of millions of ash trees.

EAB is a small, metallic-green beetle that is about ½ inch long. The larvae stage of this wood-boring insect tunnel 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 (along the trunk and main branches).

This is the farthest west this pest has been found in Iowa
"This find in Montgomery County this week marks the westernmost site that we have found EAB in Iowa to date," said Mike Kintner, Iowa Department of Agriculture & Land Stewardship EAB and gypsy moth coordinator. "This just reinforces the importance of limiting human-assisted firewood movement to reduce the spread of EAB and other injurious tree pests."

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.

Do not transport firewood across county or state lines
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 for the next two weeks, as this method can be done when the tree has a full canopy of leaves (now through the end of 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.


If you have suspicious looking ash trees, get them checked for EAB
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.

To learn more about EAB and other pests that are threatening Iowa's tree population, visit Please contact any of the following members of the Iowa EAB Team for further information:
Mike Kintner, IDALS EAB coordinator, 515-745-2877, [email protected]
Robin Pruisner, IDALS state entomologist, 515-725-1470, [email protected]
Paul Tauke, DNR state forester, 515-725-8450, [email protected]
Tivon Feeley, DNR forest health coordinator, 515-725-8453, [email protected]
Emma Hanigan, DNR urban forestry coordinator, 515-725-8454, [email protected]
Jesse Randall, ISU Extension and Outreach forester, 515-294-1168, [email protected]
Mark Shour, ISU Extension and Outreach entomologist, 515-294-5963, [email protected]
Laura Jesse, ISU Extension and Outreach entomologist, ISU Plant and Insect Diagnostic Clinic, 515-294-0581, [email protected]
Donald Lewis, ISU Extension and Outreach entomologist, 515-294-1101, [email protected].
Jeff Iles, ISU Extension and Outreach horticulturist, 515-294-3718, [email protected].

TAGS: USDA Extension
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