Dustin Vande Hoef, Iowa Department of Agriculture and Land Stewardship, 515-281-3375
Kevin Baskins, Iowa Department of Natural Resources, 515-725-8288
Laura Sternweis, Iowa State University Extension and Outreach, 515-294-0775
EMERALD ASH BORER CONFIRMED IN DUBUQUE COUNTY, IOWA
DES MOINES – The emerald ash borer (EAB), a highly destructive insect of ash trees, has been confirmed in Dubuque, Iowa. Twenty-eight of Iowa’s counties have now been confirmed positive. Since its initial discovery in Michigan in 2002, this exotic pest has spread to 25 states killing tens of millions of trees.
In addition to the southern Dubuque detection, a tree in a rural area just outside south Dubuque city limits was also detected. Both sites were declared positive after the collection of EAB larvae.
EAB is a small, metallic-green beetle that is about ½ inch long. The larvae chew into the layer of wood under the bark, cutting off the flow of water and nutrients. 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).
“Iowa now has seven counties bordering the Mississippi River that have turned up positive for EAB,” said Mike Kintner, Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator. “Unfortunate as it is, I wouldn’t be surprised to see the remaining three counties declared positive within a year.”
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 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 fall/winter, and treat beginning spring 2016 (early April to mid-May).
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, please visit www.IowaTreePests.com. Please contact any of the following members of the Iowa EAB Team for further information: