Emerald Ash Borer

What is the Emerald Ash Borer?

  • The Emerald Ash Borer is a non-native insect that poses a great threat to ash trees in the United States. Emerald Ash Borer larvae feed under the bark of ash trees killing the trees over the course of a few years due to a lack of water and nutrients. 
  • The insect is native to Asia, but was found in the U.S. in 2002. It is believed to have been introduced through infested packing material
  • Emerald Ash Borer infestations have killed hundreds of millions of trees in the U.S. and have cost municipalities, property owners, nursery operators and forest industries hundreds of millions of dollars.
  • Emerald Ash Borer populations have been known to survive harsh winters.  

How does the Emerald Ash Borer spread?

  • The Emerald Ash Borer can spread slowly on its own, but with the help of humans, these infestations can spread over miles through ash firewood, ash nursery stock and untreated ash wood products. 

Where has the Emerald Ash Borer been detected?

  • The Emerald Ash Borer has not yet been detected in North Dakota. The insect has, however, been found in parts of Minnesota, South Dakota, Manitoba, and 31 other U.S. states. 

How can I tell if a tree is infested?

  • Signs of an Emerald Ash Borer infestation include:
    • dead branches
    • vertical bark splits
    • s-shaped larval feeding galleries
    • new sprouts from the trunk, 
    • 1/8-inch, D-shaped holes made by adult beetles as they leave the tree to mate
    • Increased woodpecker activity (Woodpeckers feeding in the crowns of ash trees leave the bark a lighter color.)  
  • There are several other pests or environmental conditions that cause symptoms similar to those caused by the Emerald Ash Borer, so consulting an expert is recommended before action is taken. 
  • See the North Dakota Department of Agriculture or North Dakota Forestry Service websites for additional information. 

What can I do to prevent or treat infestation?

  • To prevent the spread of Emerald Ash Borers, don't bring firewood into North Dakota from elsewhere. Instead, burn locally gathered or purchased firewood. 
  • When planting trees, plant a variety of species. This diversity helps make North Dakota's forests, communities, and conservation plantings less susceptible to the Emerald Ash Borer and other invasive tree pests. 
  • The Emerald Ash Borer attacks only only ash trees (from the genus Fraxinus), so plant trees other than ash.
  • To help prevent Emerald Ash Borer infestations, learn the symptoms of Emerald Ash Borer infestation and report potential sightings.
  • To treat an infestation, pesticides may provide protection and delay the death of the tree. Treatment, however, is not recommended unless the presence of the beetle is confirmed within a 15-mile radius. State registered pesticides must be used with strict adherence to the label. 
  • In some areas, biocontrol stingless wasps that attack Emerald Ash Borer eggs and larva are being used on a trial basis to fight infestations. 

Where can I find more information?

What is EAB Awareness Week?

  • Each year, members of the North Dakota Forest Service, North Dakota Department of Agriculture and the NDSU Extention Service through the ND EAB Response Committee provide information for community members to help combat Emerald Ash Borer infestations and increase public awareness of the insect. 
  • During the week, information is shared with community members, and foresters place ribbons on trees that could potentially be impacted by Emerald Ash Borers, to raise awareness.
  • This year's EAB Awareness Week ran from May 21 - 25, 2018.