Hormone injections could save the ash trees on base

  • Published
  • By Ted Theopolos
  • 88th Air Base Wing Public Affairs
WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- --  A research program under way on base is evaluating the use of hormone injections to thwart a pest that has ravaged tens of millions of ash trees across the United States.

The Emerald Ash Borer is an exotic beetle native to Asia. It was unknown in North America until June 2002, when it was discovered infesting ash trees in southeast Michigan and other northern territories. Since then, the beetle has traveled to Ohio and other states killing tens of millions of ash trees along the way. So far, the damages are in the millions of dollars spent to remove and replace dead ash trees, according to the USDA Forest Service.

The 88th Air Base Wing natural resources program of the Environmental Branch is working with the Ohio State University's Ohio Agricultural Research and Development Center to use natural hormone injections to bolster the immune system of the ash trees enabling them to ward off the emerald ash borer.

Darryn Warner, Wright-Patterson Natural Resources Program Manager, estimates the base has between 1,000 to 1,500 'urban ash trees' located along streets, parking lots and other public areas.

"We have 21 ash trees that are currently being removed because of the emerald ash borer," he said.

The problem begins when the female emerald ash borer produces about 50 to 100 eggs, which are laid individually on the bark surface or between bark crevices of the tree. Once hatched, larvae burrow into the tree to feed on carbohydrates and water of the tree between the canopy and roots, which disrupts the flow of nutrients to parts of the tree. The tree slowly loses branches and within two to four years the whole tree dies.

The natural hormone injections being tested on base may be the shot that helps prevent the tree from becoming infested.

"The ash trees are injected at their base with a natural tree hormone," said Professor Pierluigi Bonello from the Ohio State University's Department of Plant Pathology. "We drill holes at the base of the tree and use a commercially available apparatus to inject the hormone. By injecting at the base of the tree, the natural hormone gets distributed up the trunk of the tree and stimulates its defenses.

"Since this is a natural hormone that is injected into the trees, there are no environmental impacts, unlike those you would have with commercial insecticides," he said.

Several samples were taken from the base, shoulder height and three-meter level of tagged trees that were injected on June 20, 2011. The samples will be tested at the university to see if the hormone is traveling up the trunk of the tree and how far.

According to Professor Bonello, this treatment is not yet available to the public.

"Treatment of ash trees with this hormone has worked with smaller ash trees, but these trees on base are much larger," Professor Bonello said. "We are testing if this environmentally friendly treatment can be used to protect high value trees."

Data and samples will be collected and studied for the next two years. If the treatment is successful, it may be possible to reverse devastation to ash trees that could otherwise run into billions of dollars of damage.