Emerald ash borer, or EAB, has been positively identified in Davenport and central rural Davis County, bringing the total of confirmed counties to 24 since this tree-killing insect was first detected in Iowa back in 2010. The Iowa Department of Agriculture made the announcement on June 10. This metallic green insect which only measures about 1/2 long and 1/8-inch wide kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America.
"With emerald ash borer already being in the area on the Illinois side of the Mississippi River, it was only a matter of time until it was found in Davenport on the Iowa side," says Mike Kintner, Iowa Department of Agriculture & Land Stewardship EAB and gypsy moth coordinator. "With these two newest findings being nearly 100 miles apart, it is a good reminder that we just never know where or when this ash-killing insect is going to reveal itself."
The city of Davenport's forestry division has been planning for the arrival of this exotic pest and has a working Emerald Ash Borer Response Plan in place. The city plans to remove ash trees infested with EAB on public properties and continue to reduce its ash tree populations in public areas. The Davis County find was in a rural area north of Bloomfield, Iowa.
Statewide quarantine on movement of firewood remains in place
Iowa has 99 counties in total, and 24 are now known to have EAB. Out of the 24 Iowa counties that have confirmed EAB findings, six have been found this year alone. A statewide quarantine, issued in February 2014, 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.
"We still strongly urge Iowans to not move firewood long distances," says Iowa's state entomologist, Robin Pruisner, who is with the Iowa Department of Agriculture & Land Stewardship. "A large portion of Iowa is not showing signs of EAB infestation; let's keep those areas EAB-free as long as possible by not moving wood that potentially harbors EAB or other tree pests. Be vigilant and report suspicious symptoms in counties that are not yet known to be infested. Report them to a member of the Iowa EAB Team."
Don't haul firewood across county or state lines
The Iowa EAB Team provides EAB diagnostic assistance to landowners and includes officials from Iowa Department of Agriculture & Land Stewardship, Iowa State University Extension, the Iowa Department of Natural Resources, USDA Animal Plant Health Inspection Service and the USDA Forest Service.
The Iowa EAB Team strongly cautions Iowans not to transport firewood across county or state lines, since the movement of firewood throughout Iowa or to other states poses the greatest threat to quickly spread EAB and other plant pests. 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, approximately 2 to 5 miles.
What about applying an insecticide to control this pest?
At this calendar date, the treatment window for soil-applied preventive treatment measures (soil injection, or soil drench, or granular application) has ended, says Kintner. Basal trunk sprays with dinotefuran can be applied until mid-June and are most effective for trees less than 18 inches at "dbh": that's the diameter of the tree's trunk at breast height, 4½ feet above the ground.
Trunk injection of an insecticide 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, says Kintner. 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 for the pest during the recommended treatment time.
Contact a member of the Iowa EAB Team if you have questions
Pruisner advises that you contact any of the 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, she says. 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 IowaTreePests.com. 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]
* 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]