Home Pruning Removals Plant Health Care Our Top Trees List Guatemala Project Our Crew Testimonials

All Production Staff
Are Members

All Production Staff Are Members MEMBER

Emerald Ash Borer Information

The emerald ash borer was discovered on private land in Wisconsin near the Village of Newburg in Ozaukee County after positive identification on August 1, 2008.  Wisconsin is the 10th state to confirm this invasive insect. The EAB has been found in a number of states to date as well as Canada.  The states of Michigan, Indiana, Ohio, Pennsylvania, Maryland, Illinois, West Virginia, Missouri, and the provinces of Quebec and Ontario in Canada have all had populations of EAB identified. 

As indicated by its name, this small beetle is a metallic green color about ½ inch in length and 1/8 inch wide. The average adult beetle can easily fit on a penny.   Adults burrow into the bark of ash trees to lay eggs.   After hatching from the eggs, the larvae being to feed on the fluid conducting vessels under the bark.  This feeding disrupts the flow of nutrients in the tree, causing die back and eventually death.  Visible signs of feeding are tunnels left by the borer underneath the bark.   Click here to see symptoms and signs of EAB from the Wisconsin DNR website.  It is related to the well-known bronze birch borer and also the two-lined chestnut borer.

Native to China and eastern Asia, the EAB probably landed in North America 12 years ago hidden in wood packing materials commonly used to ship consumer goods. It was officially identified in the summer of 2002 and is responsible for the death of up to 20 million ash trees. Now established, movement of wood primarily in the form of firewood is spreading the beetle. It is amazing how many campers really find a need to avoid paying $3 a bundle for locally produced firewood. In Michigan they have caught people trying to smuggle wood into the Upper Peninsula. You can find very good information and photos about the EAB at http://www.emeraldashborer.info. Information will likely change as more is learned so if you have ash trees you may want to check for updates. We will do our best to keep you posted.

So, what are we to do now that EAB is in Wisconsin? Detecting an infected tree can be very difficult. One of the infested trees that was identified in Illinois this year was actually pruned by a certified arborist last year without detection. This is possible because ash trees have been having numerous problems in recent years and symptoms of other types of ash decline can look similar to borer infestations in the early stages. Some of these symptoms may include dead branches near the top of the tree, leafy shoots growing from the lower trunk, D shaped exit holes in the bark and bark splits exposing S shaped tunnels on the wood just beneath the bark.  Click here to see signs and symptoms.

Most official agencies have a very conservative approach to the disease with the hope of eradication. Recently, at the International Society of Arboriculture annual conference in Minneapolis, MN, they had a four-member panel. Those connected with state institutions or agencies presented an eradication bias that told the consumer not to treat their trees until EAB has been located near you and quarantine areas have been set up. One panel member was an arborist from a respected company in the Detroit Michigan area. All panel members agreed that the EAB was coming to a neighborhood near you. However, only the arborist said, “get out there and treat trees.” He was passionate about it, and nearly bitter. He indicated that once the EAB is in a tree it is nearly impossible to preserve that tree. The only true hope for any ash tree is to have it treated with Imidacloprid before the beetle arrives.

There are a few considerations prior to treatment though.  A year ago, the state's only official option was to cut all ash trees within a half-mile of an outbreak. The policy was based on a recommendation by a national scientific panel.  A response plan approved last month no longer dictates tree removal in all cases because of both advances in pesticides and the experience of other states in the last six years. Click here to see Wisconsin’s EAB response plan in PDF format.  One option would be an attempt to eradicate any identified infestation that appears to be confined to a well-defined area. These eradication efforts would consist of eliminating every ash tree within a ½ mile radius of the infestation. This involves eminent domain and will include all ash trees whether treated or not. So, there is a risk that you may treat your tree and still have your non-symptomatic tree removed. That could be frustrating at least and heartbreaking at worst.

The second control strategy is quarantines. These areas may consist of townships, counties, groups of counties and finally the whole state. Click here to see the current quarantined counties in Wisconsin.  In the opinion of Arborists, the faster the situation moves to a quarantine, the easier life will be for everyone. No one likes to be told that someone will be removing one, half or all of the trees in their yard next week. On the flip side, it would be nice to say we could beat this thing and life can go back to normal tomorrow. Michigan has abandoned eradication efforts. Indiana is not attempting eradication and it is likely that eradication funds in Wisconsin will quickly dry up before your ash trees are eradicated.

Current recommendations are not to treat trees until the EAB is within 10-12 miles.  The downside of this is that when the EAB is detected, it has often been in the area for much longer than expected, and it is often present in a larger geographic area than originally thought.  The other problem is that in more mature trees, Imidacloprid often takes 2-3 years before it has good dispersal throughout the entire tree.  Treatments also do not work well with canopy dieback of 40% or more. Data released by Michigan State University shows that Imidacloprid is effective in controlling EAB if used properly. 

So, does all this mean you should start treating your ash tree this fall? The answer is yes, no and maybe. As I mentioned earlier, ash trees have been suffering from many problems over the last couple of decades. Many trees planted in the last 30 years have terrible form, are structurally weak and are poor specimens. Many trees have been planted in poor locations and are encroaching on the house and/or power lines. Still others are fairly young and removal and replacement would be less costly than a lifetime of fall treatments. There are also human factors that may play into your decision such as how long you intend to own your home, are there sentimental attachments to the tree, or is the tree a focal point of an entire design. The best approach is to have the tree evaluated for structure and health and see what options there are for treatment, removal or planting.

Kevin Hamm, Board Certified Master Arborist, will come to your yard to determine your specific needs.  Not every ash tree should be considered for treatment, but let a board certified master arborist tour your yard today and tailor an approach to your specific needs. Contact us today by emailing Kevin Hamm or by calling 1.866.596.5396 or 1.608.429.2307.