Emerald ash borer likely in Tosa, though not yet seen

The emerald ash borer likely has made its way into Wauwatosa - it just hasn't been discovered yet, Parks and Forestry Superintendent Ken Walbrant said.

With 30,000 city trees and thousands more on private properties, it's hard to believe the invasive beetle isn't feeding on tissues under the bark of ash trees in Tosa, he said.

Every time arborists remove trees, they check for evidence of emerald ash borer beetles, and, so far, have found none. But most infestations look like root damage from construction and aren't very identifiable until five years after the bug starts feeding.

The city started offering chemical treatments a little more than a year ago to combat the invasive beetle. In 2010, crews treated about 500 trees. Walbrant would like to see a higher number next year to better protect Wauwatosa trees.