Emerald Ash Borer (EAB)
Emerald Ash Borer (EAB) has been found in Anoka County. In late March, 2015, the Minnesota Department of Agriculture confirmed the presence of EAB in Ham Lake. A press release (PDF) was put out. The result is that Anoka County is being placed under an emergency quarantine and will eventually join other counties where EAB has been confirmed in a state and federal quarantine. The quarantine is intended to help slow the spread of EAB by limiting the movement of any items that may be infested with the insect, including ash trees and ash limbs, as well as all hardwood firewood.
EAB, an invasive insect from Asia that was first discovered in Detroit in 2002, was confirmed in St. Paul, Minnesota on May 13, 2009. Since that time, EAB has been confirmed in the following counties:
This insect is responsible for the loss of millions of ash trees in other states already. Minnesota has the second largest population of ash trees in the country and so the economic and environmental impact of EAB could be devastating. EAB appears to attack all types of ash trees regardless of whether they are healthy or under stress. Adult insects are slender, bronze or golden green with dark metallic green wings, and about ¼ to ½ inch in length. However, it is the larval stage that causes all the damage. The larvae can be 1-1¼ inches long, are cream colored with a brown head.
Signs of EAB
The larvae feed on the cambial area between the inner bark and wood, which disrupts the trees ability to transport sugars from the leaves to the roots as well as the water and nutrients from the roots to the canopy. Over several years time, an infested tree will die. Signs of EAB infestations may include the following:
- Dieback in the upper canopy (PDF)
- Epicormic branching on the trunk of the tree and woodpecker damage evident on the bark (PDF)
- S-shaped galleries created by the feeding of larvae just under the bark (PDF)
- Single larval gallery (PDF)
- D-shaped exit holes from where the adult insect emerges from the tree (PDF)