Emerald ash borer found in Dakota County

An emerald ash borer infestation was found by state workers this week in Lebanon Hills Regional Park in Eagan just north of the border with Apple Valley — the first discovery of the tree-devouring pest in Dakota County.

Due to the discovery, Dakota now joins Hennepin, Ramsey, Olmsted, Houston and Winona counties in a state and federal quarantine to help prevent the spread of emerald ash borer, an invasive insect with larva that chews up and kills ash trees.

The infested tree was detected Tuesday during a routine visual survey of ash trees by the Minnesota Department of Agriculture, said department spokesman Allen Sommerfeld. When the tree was found, a department entomologist was sent out to the park and confirmed the infestation by peeling back the bark and finding the larva, Sommerfeld said.

Despite the discovery, Sommerfeld said local efforts had helped deter the spread of the pest.

"If you look at the other states that have had emerald ash borer and have had it for a number of years, we've been really successful at slowing the spread of it," Sommerfeld said.

The invasive insect kills ash trees by tunneling into the tree's wood and feeding on its nutrients. It has killed tens of millions of ash trees in 24 states. Minnesota has about 1 billion ash trees, the most of any state in the country. The ash borer was first discovered in Minnesota in 2009. Olmsted County was just added to the quarantine in August.

The survey at the park was done as a way to find the pest in counties bordering the Ramsey and Hennepin County quarantine area. The quarantine was designed to limit the movement of items that could be infested, such as firewood. State authorities have cautioned residents not to transport firewood and instead buy it locally from vendors and burn it in the same area to prevent the spread of the pest.

In 2009, Eagan's forestry staff began implementing ash borer management activities including pesticide treatment of high priority ash trees in parks, the removal of some low priority ash trees in parks and boulevards, and the planting of replacement trees. According to the city's website, staff also have inspected hundreds of ash trees suspected of being infected on both public and private property.

Back in the summer of 2012, Eagan estimated there were 750 ash trees in city parks and 3,000 to 4,000 on boulevards along the roads.

Since the county manages the park, it would be the county's decision how to handle the infestation, Sommerfeld said.

If residents think a tree has been infected, they can visit www.mda.state.mn.us or call 1-888-545-6684.

Nicole Norfleet • 612-673-4495

Twitter: @stribnorfleet