An invasive insect pest continues to move closer and closer to Nebraska, Emerald Ash Borer. Emerald Ash Borer, EAB, has not been found in Nebraska. The closest locations to Nebraska would be the Kansas City area, which is 60 miles from the southeast corner of Nebraska, and the Creston Iowa area, which is 80 miles from the Bellevue area of Nebraska.
Emerald Ash Borer is a wood boring insect that is ½ inch long and is a metallic green color with bronze underneath the wings. The problem with Emerald Ash Borer is that it bores into healthy ash trees. We have many native borer species, but they feed on stressed or dying trees, that is what makes EAB so much worse than normal borers and it is why it is destroying so many trees.
EAB is an insect that was first found in the United States in 2002, when it was found killing ash trees in southeast Michigan. Currently, Emerald Ash Borer has been found in 25 states including Iowa, Missouri, Kansas, and Colorado, but it has not been found in Nebraska.
Emerald Ash Borer feeds only on true ash trees, which means that mountain ash is not attacked because it is in a different family and is not a true ash tree. Ash trees have opposite, compound leaves with 5-11 leaflets. They have paddle-shaped seeds that stay on the tree through the fall and into the winter months. EAB has also recently been found on Fringe Tree, which is a tree in the same family as ash, but is not very common in Nebraska.
The signs of EAB infestation include suckering at the base of an ash tree, decline in the tree from the top of the canopy downward through the tree, 1/8 inch D-shaped exit holes along the trunk and branches, increased woodpecker damage, S-shaped Serpentine galleries underneath the bark of the tree. If you notice any of these symptoms in your ash tree, you should contact your local Nebraska Extension Educator.
Emerald Ash Borer treatments are not recommended until the insect is found within 15 miles of the tree’s location. There are chemical treatments that are effective against EAB. Homeowners can use a soil application, but this is most effective on trees less than 15 inches in trunk diameter. If the tree is larger, professional tree care companies can use a trunk injection. Wait until the insect is found within 15 miles before any treatment is done because the injections wound the tree and we want to wait as long as we can before we begin wounding our trees. A homeowner should also decide if the tree is in good health and a good location before beginning treatments. Planting ash trees at this time is not recommended.
At this time, the only thing we can do to help with the ever-expanding problem is to not move firewood or wood products. Buy wood locally when camping and leave unburned firewood at the campsite when you leave.