From the Ground Up: What you need to know about the Emerald Ash Borer

Emerald Ash Borer is spreading in Iowa. Should I be doing anything with my ash tree now? And how do I know if it's infected?

According to Iowa State University Extension, the Emerald Ash Borer (EAB) has now been positively identified in Fort Madison (Lee County), which brings the total counties confirmed with the destructive pest to 26.

This metallic green insect, which only measures about half-inch long and an eighth-inch wide, kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America.

So far, it has not been spotted in Linn County. ISU entomologists are continuing to track the movement of borer on a county-by-county basis and the entire state has been quarantined for Emerald Ash Borer.

So what's that quarantine mean?

The larvae of Emerald Ash Borer can be transported under tree bark, so don't transport firewood across county or state lines. A statewide quarantine remains in place, restricting the movement of hardwood firewood, ash logs, wood chips and ash tree nursery stock out of Iowa and into non-quarantined areas of other states.

There are now Federal and State Laws prohibiting the transportation of the above mentioned items from Emerald Ash Borer infested areas. Firewood that is sold in Iowa must be labeled to include the source company or person, location of harvest, and tree species.

Green ash, white ash, black ash, blue ash, and pumpkin ash trees are hosts for Emerald Ash Borer; mountain ashes are not hosts.

What to look for if you suspect your ash tree might be infected (According to ISU Extension):

• Canopy thinning or dying branches in the top of the tree

• Water sprouts (suckers) halfway up the trunk

• Feeding notches on edge of leaflets

• Woodpecker feeding sites/many bark flakes on lawn

• S-shaped feeding galleries under dead bark

• D-shaped exit holes (1/8 inch diameter)

As of early July, the best option for managing Emerald Ash Borer is trunk injection. This can be done through August when the tree has a full canopy of leaves, provided there is good ground moisture. If you have an ash tree you want to protect and you are within 15 miles of known infestation, talk to reputable landscape companies to get bids to treat during this window of opportunity. If you are not in a known infested area, it may be too soon to treat your tree.

Contact one of the following if you suspect Emerald Ash Borer in your tree:

• State Entomologist Office, IDALS: (515) 725-1465

• Iowa DNR Forestry: (515) 725-8453

• ISU Extension and Outreach: (515) 294-1101

For more detailed information about EAB, including more details about treatment, see a handout published July 8.

Iowa Emerald Ash Borer Infestation

• Jean Murray is a Linn County Master Gardener. For questions, contact the Linn County Extension Hortline at (319) 447-0647 from 10 a.m. to noon weekdays.