Emerald Ash Borer Disease

Emerald ash borer (EAB) is an Asian beetle that threatens the existence of ash trees throughout North America. These insect pests have killed millions of ash trees in urban areas, woodlots, and nurseries; spreading via infested nursery stock and firewood.

  Emergency EAB Quarantine

Emerald Ash Borer (EAB) has arrived in Chisago County. The Minnesota Department of Agriculture (MDA) enacted a quarantine to limit the movement of firewood and ash material into Minnesota and out of infested counties. This will reduce the risk of further spreading the tree-killing insect. Learn more about the EAB program here.

 Active Period

The active period typically begins in May and ends in early October.

Because EAB can fly and infest nearby ash trees, avoid removing ash branches, stumps and trees. Only prune or remove trees if absolutely necessary and transport wood to the nearest ash tree waste disposal site.

  Management Plan

The City of Wyoming has an approved EAB management plan for ash trees located on street boulevards and public areas. The plan recommends the selective treatment and removal of ash trees over a three year period. The City selected Hugo Tree Care to implement this plan.

 Limit The Spread

  1. Know what to look for - Be aware of what EAB looks like as well as the symptoms of an EAB-infested tree. Use this diagnostic tool to see if you can clearly rule out EAB.
  2. Report any suspected insects or declining ash trees - If you can't easily rule out EAB, contact Report A Pest to report your suspicions. There have been many cases where the public was the first to find an initial infestation in an area.
  3. Don't move firewood - Most EAB will generally move only about one-half to one mile a year from infested sites, but with help from people, it can travel hundreds of miles when carried in firewood and other wood products or nursery stock. Don't transport firewood when you go camping or are buying it for home use. Buy the wood you need at local sites or at the campgrounds you are visiting.

  About Emerald Ash Borer

EAB is a quarantined invasive species. Items that could transport this insect may not be moved without permission from the MDA. Please report any EAB you spot at Report A Pest.


Where does it come from?

This exotic borer is a native of Asia. It was first found in Minnesota in May 2009 in St. Paul. EAB has also been found in many other states, as shown on this map. It has also been discovered in Ontario and Quebec.


What does it look like?

EAB is a type of metallic wood-boring beetle (family Buprestidae). It is a little larger and much more brightly colored than bronze birch borers and two-lined chestnut borers.


AdultsEmerald ash borer on leaf.

  • 1/3 to 1/2 inch long slender body

  • Widest just behind the head, gradually tapering back to the abdomen

  • Bright iridescent green to copper-green

  • May have a copper-colored area behind the head

  • Purplish-magenta underneath wings


LarvaEmerald ash borer larva inside wood.

  • 1 to 1.25 inches when fully grown

  • White, flat body with small brownish head

  • No legs

  • A pair of small pincer-like appendages on the tip of the abdomen


What does it attack?

EAB attacks all species of North American ash trees from as small as one-inch diameter to large mature trees. EAB has also been found to attack white fringetree, not commonly planted in Minnesota. Once an ash is attacked by EAB, it will be killed if it is not protected.


How destructive is EAB?

This destructive beetle has killed hundreds of millions of ash trees where it has been discovered. There are nearly one billion ash trees in Minnesota, one of the largest concentrations of ash in the country. Ash trees are abundant in Minnesota forests as well as in urban landscapes. Research has found little to no resistance to EAB in our native ash.


How fast does EAB move?

EAB will move only about one half to one mile a year from infested sites, but people can carry it hundreds of miles when transporting firewood and other wood products or nursery stock.


Can an Ash tree be protected?

Ash trees can be protected from EAB with available insecticides.