Example of a tree infested with Emerald Ash borer

3 Tips to Detect Emerald Ash Borer

The emerald ash borer

The emerald ash borer is one of the most dreaded tree pests because it can kill formerly healthy trees just four to five years after infestation. Once an ash tree is plagued with the EAB, there is usually little that can be done to preserve the tree.

Photo of tree afected by Emerald Ash Borer beginning

The emerald ash borer is an intrusive species in North America born in northeast Asia. This insect was primarily seen in North America in the Detroit area in 2002. The adult emerald ash borer is shining metallic-green in color and is only about half an inch long.

Its larvae, accountable for most damage, are around one inch long when matured and white with segmented bodies and flat heads. The larvae impair ash trees by feeding on the wood underneath the bark and tedious perceptible tunnels, known as galleries, that disrupt the trees’ flow of water and nutrients. Infested trees experience dieback of the greenery and branches and the splitting of the bark.

The damage induced by emerald ash borers is not immediately conspicuous because most damage is beneath the bark. Many of the indications of ash borers become more evident later as the larvae galleries carried in the sapwood distort the flow of water and nutrients. A tree plagued with emerald ash borers may show, know the symptoms of EAB here:

Symptoms of the Emerald Ash Borer

  • D-shaped exit cavities on the outer bark where the adults occurred
  • Galleries of winding tunnels under the bark
  • Diverging bark caused by the boring of the larvae
  • Dieback of the canopy as the discharge of nutrients and water is disrupted.
  • Suckers may arise towards the base of the tree.
  • A proliferation in woodpecker activity on your ash trees is also a probable sign as they forage on emerald ash borer larva.
  • The bright metallic-green beetle may be smaller than a dime, but it is capable of taking down ash trees thousands of times its size. Adults are typically 1/4-1/2 inch long and ⅛ inch wide. Eggs are extremely small—approximately 1/25 inch—and are reddish-brown in color.
Photo of tree afected by Emerald Ash Borer detail

Locating adult emerald ash borers does not mean that they have infested the tree yet, but you should reach out to a professional arborist right away from Alliance Tree Care Inc. is a premier provider of trusted tree care services covering the entire twin cities metro areas and beyond but not limited to Oak Park Heights, Stillwater, Dellwood, White Bear Lake, Mahtomedi, Lake Elmo, Hugo, Forest Lake, Marine on the St. Croix, Pine Springs, Oakdale, Woodbury, Maplewood, St. Paul, Little Canada, Vadnais Heights, Roseville, Shoreview, North Oaks, Arden Hills.  Not to worry, if your city is not listed here, that doesn’t mean we don’t work in your city, it simply means we haven’t worked there yet this season.

Emerald Ash Borer Control

As mentioned earlier, there is often little that can be done to save a tree infested with the emerald ash borer as it kills trees 4-5 years after initial infestation. However, control measures can decrease the damage to infested trees and prevent the infestations from scattering. Some of the most compelling emerald ash borer treatment and control methods:

  • When an emerald ash borer infestation arises, local and state governments will likely assess a quarantine to help prevent the spread of such infestations. Transporting ash wood outside the quarantined locations is prohibited if the wood has living emerald ash borer larvae. Infested trees are often released in urban areas and replaced with a separate tree species, while infested trees in rural sites are harvested for lumber or firewood. If an infected tree on private property requires removal, it is best to have a professional deliver tree removal.
  • Insecticides can treat and prevent emerald ash borer infestations, but they are only used for infested trees in urban areas. Insecticides are generally injected directly into the tree or soil drench, sufficient for 1 to 3 years. If a tree is infected with insecticides after an infestation, it may experience further damage. A professional arborist should use these insecticides.
  • As we have already noted, the emerald ash borer has no natural predators in North America. In 2007, the USDA authorized the import and release of four distinct non-stinging wasps that are natural predators of the emerald ash borer. A couple of these species have improved their populations in the U.S. and have had some success controlling emerald ash borer populations.