Since the first Iowa detection in 2010, emerald ash borer (EAB) continues to expand its range across the Iowa landscape. With confirmed detections now in 50 counties, EAB has now reached more than half of Iowa counties. EAB is an exotic pest that attacks and kills ash trees.

The recent finds involve ash trees in Belle Plaine (Benton County), Alta (Buena Vista County), Charles City (Floyd County), Cresco (Howard County), and rural SW Milo area (Warren County). Insect samples were submitted from these sites and positively identified by the USDA.

“This is traditionally the time of year we experience an increase in calls from Iowan suspecting EAB infested trees,” said Mike Kintner, Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator. “Now that trees have been given the opportunity to fully leaf out for the season, the symptoms of an ash tree under attack by EAB are more noticeable.”

EAB-infested ash trees display canopy dieback beginning at the top of the tree and progressing downward, S-shaped feeding galleries under dead or splitting bark, D-shaped exit holes, water

sprouts along the trunk and main branches, and bark that is stripped off as a result of woodpeckers hunting for EAB larvae.

The adult beetle is metallic green in color and measures approximately one-half inch long and can be observed during the summer months. The larvae are the damaging stage and burrow through the inner layer of bark, feeding on the vascular tissue that moves life-sustaining water and nutrients throughout the tree. Starved trees usually die within two to four years.

The Iowa EAB Team provides EAB diagnostic assistance to landowners and includes officials from Iowa Department of Agriculture and Land Stewardship (IDALS), Iowa State University Extension and Outreach, the Iowa Department of Natural Resources (DNR), USDA Animal and Plant Health Inspection Service and the USDA Forest Service. Anyone who suspects an infested ash tree in a county not known to have EAB is urged to contact the Iowa EAB Team. 

At this calendar date, the treatment window for soil-applied preventive treatment measures (soil injection, soil drench, or granular application) has ended. Basal trunk sprays for trees 23 inches diameter (measured 4.5 feet above the ground) can be made until mid-June. Trunk injections can be done now through the end of August if a landowner is interested in protecting a valuable and healthy ash tree within 15 miles of a known infestation. Good ground moisture is essential for systemic insecticide movement in a tree. Full details are available in Iowa State University Extension and Outreach publication PM2084: https://store.extension.iastate.edu/product/13114

A federal quarantine, enforced by the U.S. Department of Agriculture, remains in effect and prohibits the movement of all hardwood firewood and ash articles out of Iowa into non-quarantined areas of other states without a valid compliance agreement or permit. To help reduce the spread of EAB and other destructive tree-killing pests, Iowans are strongly encouraged to use locally sourced firewood. The transport of unknowingly infested firewood is the quickest way to spread EAB to new areas. 

Additional EAB information and maps are available at www.IowaTreePests.com.

For more information contact any of the following members of the Iowa EAB Team:

• Mike Kintner, IDALS EAB coordinator, 515-745-2877, Mike.Kintner@IowaAgriculture.gov
• Robin Pruisner, IDALS state entomologist, 515-725-1470, Robin.Pruisner@IowaAgriculture.gov
• Paul Tauke, DNR state forester, 515-725-8450, Paul.Tauke@dnr.iowa.gov
• Tivon Feeley, DNR forest health coordinator, 515-725-8453, Tivon.feeley@dnr.iowa.gov
• Emma Hanigan, DNR urban forestry coordinator, 515-249-1732, Emma.Hanigan@dnr.iowa.gov
• Jesse Randall, ISU Extension and Outreach forester, 515-294-1168, Randallj@iastate.edu
• Mark Shour, ISU Extension and Outreach entomologist, 515-294-5963, mshour@iastate.edu
• Laura Iles, ISU Extension and Outreach entomologist, ISU Plant and Insect Diagnostic Clinic, 515-294-0581, ljesse@iastate.edu
• Donald Lewis, ISU Extension and Outreach entomologist, 515-294-1101, drlewis@iastate.edu.
• Jeff Iles, ISU Extension and Outreach horticulturist, 515-294-3718, iles@iastate.edu

In an effort to increase awareness of invasive species and the impact they have on Iowa’s ecosystems and economy, Governor Branstad recently proclaimed June as Invasive Species Awareness Month in Iowa.

Each year, Iowa spends millions of dollars on the control of invasive plants, insects, animal species and diseases in woodlands, wetlands, waterbodies and urban areas around the state.

“The discovery and spread of emerald ash borer in Iowa has brought to light the devastating effect an invasive species can have,” says Chuck Gipp, DNR Director. 

Invasive Species Awareness Month provides an opportunity for the public and private sectors to join forces, and take action against the introduction and spread of invasive species in the Iowa.

“We need to be vigilant in preventing further introduction of unwanted insect, plant and animal species into our neighborhoods and ecosystems,” adds Gipp, “and knowledge is the first step in this effort.” 

The June proclamation is particularly timely as outdoor enthusiasts head out to boat, fish and camp. Iowa’s aquatic invasive species law is aimed at preventing recreationists from transporting invasive fish, plants and other aquatic life. Details on how to prevent aquatic nuisance species can be found at www.iowadnr.gov/Fishing/About-Fishing-in-Iowa/Fighting-Invasive-Species

Campers should only use local firewood when travelling away from home to avoid the potential spread of emerald ash borer. Research has shown that emerald ash borers can only fly a few miles, which helps slow its natural spread. However, it is easily transported to new areas when people inadvertently move emerald ash borer larvae inside of infested firewood, ash nursery stock, and other ash items. 

More information on invasive species can be found on the DNR website, www.iowadnr.gov , by searching EAB, invasive plants, invasive fish, aquatic invasive invertebrates or aquatic invasive plants.