Emerald ash borer discovered in western Iowa

The tree-killing emerald ash borer has been discovered in Missouri Valley in far western Iowa, making Hamilton the 35th county in the state where the pest has been confirmed.

'This find marks the westernmost site that we have found EAB in Iowa to date,” said Mike Kintner, Iowa Department of Agriculture and Land Stewardship emerald ash borer and gypsy moth coordinator.

The ash borer has been detected in six new Iowa counties so far this year, Kintner said.

A certified arborist contacted the emerald ash borer team after a Missouri Valley resident expressed concern about an ash tree on city property.

Upon investigation, the team collected an insect that was confirmed as an ash borer by the USDA Systematic Entomology Laboratory.

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.

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

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

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