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Bay County Insecticide Program Treats 2,500 Damaged Trees08-12-13 | News

Bay County Insecticide Program Treats 2,500 Damaged Trees

Jeffrey Merkle with Bay Landscaping injects trees along Adams Street in Bay City, Mich., for emerald ash borers. This treatment is part of an ongoing project through the Bay County Gypsy Moth Suppression Program.

County-wide treatment of trees plagued by invasive emerald ash borers has wrapped up for the third year, but the fate of those ash trees is uncertain until autumn.

Alicia Wallace, coordinator of the Bay County Gypsy Moth Suppression Program in Michigan, oversees the county's ash-borer control program as well. She said workers began treating damaged trees with insecticide in May and completed the task in early August.

A total of 2,567 ash trees ranging from Auburn and Bay City, north to Pinconning, were tagged for treatment. Wallace estimated that about 2,500 ash trees received the insecticide.

"Treatment took place in most of the township parks, street trees and some ash trees at a majority of public schools and publicly owned cemeteries Oak Ridge and Pine Ridge," Wallace said. "The final count of tagged trees that were treated isn't complete yet. Some trees had either been storm damaged or too far gone, so we didn't treat them."

The applicators that the city is using to treat the publicly owned trees are Bay Landscaping, TruGreen out of Freeland and Begick Nursery and Garden Center. The program, initiated in in 2011, has a $150,000 budget allocated this year for treatment of damaged ash trees. Wallace said that appropriate treatment depends on the size and location of affected trees.

"We are using a two-pronged approach to best help ash trees survive," Wallace said. "We have sufficient funds to treat everything on publicly owned property. Concentrated insecticide is used on larger trees in a grass type setting, and we have released parasites that are exclusive to emerald ash borers in woodlots."

Evidence suggests insecticide is an effective method, with small doses of a concentrated insecticide administered into holes drilled into the base of each tree. The treatment needs to be re-administered every two years.

"Last fall, we determined 95 percent of the ash trees had responded well to treatment and 5 percent would not be treated again," Wallace said. "Our evaluation of the trees happens in late summer and early fall when trees still have leaves, but it is easier to notice if there is a lot of dieback or if they are lagging."

The assessment is scheduled to begin next week and continue through September. Trees that appear viable will next receive treatment in 2015. Next year, 800 additional trees currently too small for treatment or missed in the inaugural year, will receive their second dose of treatment.

The first Michigan emerald ash borer infestation was reported in 2002. It has been illegal to plant ash trees since 2004, and the invasive species was discovered in Bay County in 2007.