Emerald Ash Borer

Emerald ash borer (EAB) is a non-native (invasive) insect from Asia that kills ash trees. According to the Minnesota Department of Agriculture (MDA), resistance against EAB has not been found in any native North American ash tree populations. In areas where EAB has become established, ash tree mortality rates approach 100 percent. Once emerald ash borer infests an area, it cannot be eradicated. It has killed over 25 million ash trees in the United States.

Minnesota is home to approximately 900 million ash trees, the most of any state, making Minnesota susceptible to the destruction caused by EAB. Trees become infested when adult beetles lay eggs on the bark. The eggs hatch into larvae that bore into the tree, eventually killing it.


EAB was discovered in Minnesota in 2009 In the City of St. Paul. Infestations of EAB were found at Lebanon Hills campground in Eagan in 2014 and near Cedar Avenue and County Road 42 in Apple Valley in 2016. EAB was detected in Lakeville in October 2017, and the City has started preparing for the effects of the infestation.

For the most current map of EAB distribution in Minnesota, visit the Minnesota Department of Agriculture website.

Signs and Symptoms of an EAB Infestation


There are many reasons an ash tree might have dead branches or dieback which can be symptoms of EAB. The best sign to look for is woodpecker activity, where flecks of bark have been stripped away to reveal lighter bark (blonding). This is most easily seen in late winter or early spring. Another sign to look for is bark splits on the trunk or branches.

The City will only accept select ash tree inspection requests. Before requesting an inspection, use the links below to learn more about signs and symptoms of EAB.