Emerald Ash Borer confirmed in two more Iowa counties

Emerald ash borer has been confirmed in two more southeast Iowa counties, bringing to 34 — or more than a third of the state — the number of infested counties since the state's first detection in 2010.

In Washington County, the discovery in Brighton came after a concerned homeowner alerted Iowa officials to an ash tree showing characteristic symptoms. In Van Buren County, the affected tree was noticed in a public area in Birmingham.

In both cases ash borer was confirmed, following an examination of specimens, by the USDA Systematic Entomology Laboratory in Maryland.

Emerald Ash Borer, an eastern Asia native, was detected in the United States near Detroit in 2002. It has since spread to 27 states and killed tens of millions of trees.

'We are not surprised to find more infestations in southeast Iowa,' said Mike Kintner, Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator.

Since July 2013, when southeast Iowa's first confirmation was made in Burlington, the insect has spread throughout the region, with the exception of Iowa County.

Signs of infested ash trees include 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 increased woodpecker activity to the bark.

Emerald Ash Borer, widely considered one of the most destructive forest pests ever in North America, kills all ash species by larval burrowing under the bark and eating the actively growing layers of the tree.

Iowa has an estimated 52 million rural ash trees and approximately 3.1 million more ash trees in urban areas, according to the USDA Forest Service.

Iowans should use only locally sourced firewood, burning it in the same county where it was purchased. Firewood is a vehicle for the movement of the emerald ash borer and other tree-killing pests.

With the exception of trunk injection, the window has closed for preventive methods against emerald ash borer this year. Trunk injections can be done by certified pesticide applicators until Sept. 1.