Magazine On-line [summer 2013]
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Around Campus

Emerald As

Kissing TreeTransylvania defends romantic tradition against alien invaders

Don’t kiss this tree good-bye.

Transylvania is treating its storied Kissing Tree to keep emerald ash borers from killing it.

The beetles have destroyed tens of thousands of ash trees from Nebraska to Quebec—and they’re spreading across Lexington.

The university’s white ash, ringed with a bench and honored by a plaque, was a safe place for students to smooch back when doing so in public was a no-no. The Chronicle of Higher Education mentioned it in a story about the most romantic college campus locales.

“We did not want anything to happen to that tree,” grounds foreman Ron Henson said. “It’s not one that you can replace.”

So far it shows no signs of infestation by ash borers, which experts say are the most damaging pests ever to chew through North America’s forests.

As adults, the beetles’ wings have the green glitter finish of a bass boat. And their bodies are a little shorter than Abraham Lincoln’s penny profile.

While the adults feed on leaves, their larvae are what kills the trees. After hatching on or under the bark, they bore into the outer layer of wood, eating through the nutrient channels. The trees die from this vascular damage.

To treat the Kissing Tree, Dave Leonard Tree Specialists drilled small holes around the circumference; every two years workers hook up a harness with injectors that release emamectin benzoate into the xylem and phloem. The insecticide kills ash borer larvae that may infest the tree.

When the leaves are coming out is a good time to do this, because a tree’s sap—and with it the insecticide—are vigorously rising. Co-owner Dave Leonard said he last treated the Kissing Tree in May of 2012.

This ash’s roots grow in a confined space so the tree needs more care in general. This includes pruning, dead wood removal, fertilization, and soil aeration. Being in good health helps a tree stave off infestation.

Leonard said he often stops to monitor the ash when he passes by. “It’s the most important tree probably on campus,” he said.

His company has seen symptoms of ash borers locally. For the last few years, these cases have been limited to the south side of town but “they will be all over Lexington,” Leonard said of the borers.

A symptom of infestation is crown dieback, biology professor Sarah Bray said.

A damaged tree also will send up suckers from its roots and have D-shaped holes in the bark.

The first ash borer sighting in Fayette County was in 2009. The insect was introduced into the U.S. in Michigan seven years earlier—probably in Chinese packing material. “It pretty quickly decimated ashes in Michigan,” Bray said.

“Our native ashes have no resistance, because they’ve had no evolutionary history with this species.”

Starting in 2010, people were no longer allowed to move firewood out of Fayette County. “The reason why [the borers] moved so quickly is you end up cutting down trees for firewood, and that ends up getting transported,” Bray said.

Ash trees are abundant in urban settings, in part because they were planted to replace elms—which Dutch elm disease depleted. The dense stands of shady ashes in cities make them an easier target for infestation.

Bray said she is happy the university is treating the Kissing Tree, which won’t likely escape a visit from these glitzy gatecrashers. “It’s only a matter of time.”


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