Daniel Chi / Asst. photo editor
This fall, one species of trees on Ohio State’s campus might not be dropping leaves.
That’s because they have no leaves to drop. Ash trees around campus were without leaves this summer as a result of the Emerald Ash Borer (EAB) and in many cases the trees have been cut down in the past few years or will be cut down in the future.
EAB is a beetle from Asia, and the invasive insect is responsible for killing ash trees was introduced to the U.S. in the 1990s. Reports of it killing ash trees in Detroit and Windsor, Canada, began in 2002, and the insect was reported to be in Ohio by 2003, according to the Ohio Department of Agriculture website.
“We have taken out quite a few (ash trees) on campus,” said Stephen Volkmann, OSU’s university landscape architect.
Columbus City forester Joe Sulak said the plan to protect Columbus from the damage of the infestation will cost the city an estimated $12 million over 10 years.
EAB larvae eat the phloem, the part of the tree that carries nutrients. According to the Ohio Department of Agriculture website, North American ash trees die within three to five years of infestation.
Pierluigi Bonello, a professor in plant pathology at OSU, said while EAB easily kills North American ash it does not kill Asian ash.
The relationship between tree hosts and insect pests is a “tug of war,” Bonello said.
“In the course of co-evolution, you have one side of the interaction, which is the pest, which develops new weapons to attack the host. Over time, the host evolves to develop counter measures,” Bonello said.
He said the EAB and North American ash species were never able to go through this process, and therefore have no defense against the insects.
“We think that is basically what is driving the epidemic. Not so much the absence of enemies for the insect, which is another possibility,” Bonello said.
According to the Ohio Department of Agriculture, EAB has spread to 63 of Ohio’s 88 counties, including Franklin County and OSU’s campus. Columbus has a plan to handle the infestation.
“The primary effort is removal to prevent hazards,” said Sulak. “The insect attacks trees from the top down, so they can basically fall apart.”
He explained that if a large windstorm came, similar to one that blew through campus in June, limbs could fall off the infested trees and potentially fall on buildings or roads. Bonello said the infestation can be treated, but with little avail.
The OSU Columbus campus is one of eight Tree Campus USA sites in Ohio, according to Buckeyes Yard and Garden onLine. A Tree Campus is one that has been designated by the a Arbor Day Foundation as a college campus that demonstrates exemplary care of its trees.
Sulak said each of the 30,000 ash trees in Columbus will inevitably be removed, but a new tree of a different species will be planted in its place.
Kyle Kuebler, a second-year in aerospace engineering, said losing the ash trees is tough.
“Something should be done about it. It is not good to lose all those trees,” Kuebler said. “Especially the one tree that is in the yard (of his Hilliard, Ohio, home). You know, I grew up with that tree and I really do not want to see it go.”
But Kuebler acknowledged that the tree could be replaced.
Bonello had some suggestions for those who really want to do something about EAB.
“I suppose if the general student population, if they are engaged, and they really care about these sorts of issues they can always make noise,” Bonello said. “In terms of talking to the right people, pressing government agencies and politicians to pay attention to these issues.”