Polk County Conservation

Emerald Ash Borer

The emerald ash borer is a non-native, small green wood-boring insect that attacks and kills ash trees. The adults live on the outside of ash trees feeding on the leaves during summer months.

The larvae look similar to white grubs and feed on the living plant tissue underneath the bark of ash trees. The trees are killed by the tunneling activity of the larvae under the tree's bark, which disrupts the flow of water and nutrients.

First detected in the United States in 2002, the borer has rapidly spread west, and has now been found in various counties within Iowa. For this reason, Iowa was placed under quarantine in February of 2014 by the Iowa Department of Agriculture and Land Stewardship (IDALS) and the Iowa Department of Natural Resources.

Iowans are encouraged not to transport firewood (or other infested materials) across county or state lines, since moving firewood poses the greatest threat to quickly spreading this insect, and others. Working together, we can protect local ash trees for as long as possible.


Photos: adult emerald ash borer, top left (credit: www.forestryimages.org); emerald ash borer larva, bottom left (credit: www.forestryimages.org); tunnelling emerald ash borer larva, center (credit: Todd Voss, IDALS); suspect ash trees, right (credit: M.H. Shour, ISU Extension).

Management Strategy

Polk County Conservation has prepared a sensible management strategy for the existing ash trees on county-owned land. This strategy may be viewed by clicking here.

Useful Links

Iowa Tree Pests Website

Iowa DNR EAB Website

Iowa State University Extension | Emerald Ash Borer 

National EAB Website


Contact Us

Administration Office
12130 NW 128th St
Granger, IA 50109

P: (515) 323-5300
F: (515) 323-5354

Monday – Friday, 8:00 a.m. – 4:30 p.m.

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