Fighting emerald ash borer will be a costly battle

"There's no stopping the green menace."

It may sound like a line from a science fiction movie, but that somber message is actually being sent to a growing number of states -- including Minnesota -- by the U.S. Department of Agriculture regarding a real menace: the emerald ash borer.

Instead of reaching for their 3-D glasses, officials from metro-area cities such as Burnsville are reaching for their checkbooks as the tree-killing beetle draws near.

The emerald ash borer already has been discovered in the Twin Cities, and its anticipated migration could make Burnsville one of the next towns infested. City officials expect to be hit hard.

Burnsville has an estimated 12,000 ash trees on public property, not including those in the city's large wooded areas. With no natural predator of the beetle present, all 12,000 trees are in danger of being killed.

According to Terry Schultz, Burnsville's director of parks and natural resources, the price tag on replacing them is a staggering $14 million.

Burnsville's plight is one that, sooner or later, will play out across the state. With 937 million ash trees in Minnesota and no way to stop the infestation, the damage will be monumental.

In the meantime, scientists across the country continue their research on ways to slow the beetle's migration.

Out of Asia, by way of Detroit

The emerald ash borer's larvae are what proves fatal to the trees, feeding on the inner bark, which prevents water and nutrients from moving through a tree.

"We're not going to be able to eliminate it," Schultz said. "You can protect an individual tree with the insecticide, but you're not going to be able to stop the emerald ash borer's progress."

The emerald ash borer's natural habitat is Asia. It was first discovered in the United States near Detroit in the summer of 2002. While no one knows for sure how it got there, the likely explanation is via infested ash wood used as crating material for shipping.

Minneapolis anticipates spending $26 million to remove and replace ash trees on public property, not including parks and natural areas. Burnsville officials estimate it will cost $8.1 million to remove the city's 12,000 ash trees.

Harder to quantify is what the loss of the trees will mean in terms of increased cooling and heating bills for businesses and homeowners.

Burnsville has begun instituting a program to educate the public on the issue, including ways to identify the emerald ash borer and how to properly dispose of infested trees. Residents will be responsible for removal and disposal of trees on private property. Burnsville plans to register companies that have been deemed qualified to remove the trees properly.

The city will hold an annual tree sale for residents who want to replace fallen ash trees with a different type of tree.

Meanwhile, the city will identify key ash trees that it hopes to save with the use of insecticides. Residents also will have the option of using insecticides to protect ash trees in their yards.