LANSING – Ash trees in the Great Lakes region are still in danger because of metallic green beetles that are spreading rapidly. This is despite a report that a lower number of trees died from detrimental insects in the U.S. in 2011 than in prior years.
According to the U.S. Forest Service, the drought that has plagued the region can also cause sick and dying trees to fail.
Many of the area’s ash trees are seeing color changes or dropping leaves much sooner than usual. These are both methods that aid trees in dealing with drought, according to Deborah McCullough, a Michigan State University entomologist.
“It’s possible some insect populations could grow next summer because of this year’s drought, but that is just really hard to predict,” she said.
Experts say that the emerald ash borers will not be leaving the area in the near future without proper ash borer treatment.
Robert Mangold, associate deputy chief for research and development at the U.S. Forest Service was quoted as saying,”Michigan has the worst infestation.” The beetles are so bad that the agency has halted surveying Michigan for this invasive insect.
Mangold stated that every single county in Michigan is now infested with the ash borer beetles.
McCullough said that there are roughly 80 million dead ash trees just in the southern half of the Lower Peninsula region of Michigan alone. There is only a limited amount of funding to do these surveys so the agency is focusing on states that do not have a critical outbreak at this time.
According to the Forest Service, even though western forests saw a drop in deadly insects such as the mountain pine beetle, which damaged 3 million less acres than in 2010, the emerald ash borer continues to spread throughout the eastern forests.
McCullough stated, “The ash borer is the most destructive insect that’s ever invaded North America.” It kills trees in every area, whether forest or urban, and it is affecting virtually every species of ash tree in North America alone.
In 2011, the beetle had spread to all eight of the Great Lakes states and into Ontario as stated in their report.
Mangold said the sheer volume of forests prevent the pesticide injections that often can save lone trees.
He said, “It’s beyond eradication in most areas, especially in the Great Lakes.” The Forest Service is working on biological management and control methods for the tree farmers to use, but concern is mounting about the dwindling ash resource.
Mangold stated that they are trying to manage these beetles but the problem continues to grow.
Ash borers continue to spread through flying. The Great Lakes remain extremely vulnerable because these insects often are hidden in wooden packing materials used to stabilize cargo on ships. There are rules requiring pesticides for ash borer treatment, but they don’t always work. Mangold states that “There’s so much trade coming in that sometimes things get through.”
Ash borer beetles can also be spread long distances on trees that are bought at local garden centers and by moving firewood.
There is a light at the end of the tunnel at least where other destructive creatures are concerned. The gypsy moth has decreased at the same time the ash borer has infiltrated the Great Lakes regions. This large increase is probably due to the wet springs of the last several years, according to Mangold.
Mangold also spoke about the Forest Service’s program called Slow the Spread that has managed to significantly reduce the number of gypsy moths.