Photo by David Cappaert, bugwood.org
If you are wondering if the emerald ash borer (EAB) is in your yard, or perhaps in your community, it has not been confirmed nor identified in western Nebraska by the state Forest Service nor the Nebraska Department of Agriculture.The emerald ash borer was found in an Omaha park, and in Cass County, in June 2016, Southwest District Forester Rachel Allison said Monday.
“If you have heard directly from someone that it is here, that is not correct,” she said. “If you have an insect which is suggested to be the EAB, you should have the insect identified and passed along to one of the agencies noted above.”
Allison said that it is very likely that it is another insect that has already been here, such as the lilac (ash) borer or other tree borer, which have been associated with ash trees for many years. “These insects are prevalent in trees that are stressed by drought, early cold and later spring freezes, overwatered lawns, as well as lawn herbicides used to kill dandelions and other weeds,” she said. “Most importantly, these insects that are here now and are the real culprit in western Nebraska need to be treated differently than what would be used for the EAB.”
What happens if you do treat your ash tree before EAB gets to your community?
Allison said there is the possibility that EAB may not reach the western communities for several years, or if it does arrive in a year or two, we will see it in other communities as it advances or moves across the state.
Treatments for EAB are usually applied by one of two methods -- injection or soil drench. If you decide to have the tree injected, what happens is that the tree will be damaged some by the injection, and also, each time the tree is injected over the years the tree is damaged more and more. It is best to wait until EAB is known to be nearby before beginning treatments so damage to the tree can be minimized.
How do bark injections damage the tree?
Drilling a hole and applying a liquid under the bark of the tree creates an area of dead tissue and several applications with multiple injection sites make it difficult for the tree to move the water and nutrients it needs to survive.
The tree reacts to these injected sites as a wound and develops defensive tissue, restricting and directing the normal flow of healthy tissue away from that area. Yearly or even every other year, injections eventually end up blocking the flow of very important water and nutrients from the ground to support and maintain the health of the tree.
The other method, a soil drench, is harmful to the tree and it will also harm other beneficial insects in the soil around your ash tree.
Those insects help to create living soil, very important to nutrient break down and development of organic matter critical for a healthy tree and plant survival. While it may seem simple to apply the pesticide and directly target the problem insects, research shows that this product, imidacloprid, leads to the decline of many insect, butterfly and bird species.
There are also several limitations to consider when applying the soil drench — the pesticide cannot be used in all locations, particularly wet, sandy or compacted sites typical of some yards where trees are found. Also, a soil drench has restrictions for the amount that can be placed within a city block.
What should you do?
Allison suggests that first, don’t apply a pesticide when you’re not sure of the reason for the treatment, or not sure if you have EAB.
Second, learn why the treatment for EAB is both damaging to the tree and harmful to the environment.
Third, if you have an ash tree and are concerned about its health and the possibility of EAB being present, visit this website http://eabne.info/ for information or email your question to this site firstname.lastname@example.org.