Invasive beetle not yet confirmed in Utah, but tree care companies beg to differ
Some tree care companies believe a tree-munching insect called the emerald ash borer has already begun its attack in Utah, but researchers worry there is premature panic about its arrival.
“We need to make sure people do not get swindled,” said Ryan Davis, an entomologist at Utah State University. Davis and fellow entomologist Lori Spears lead educational workshops across Utah to discuss the threats of the emerald ash borer, which has killed 50 million trees in North America so far.
Confirmed in Boulder, Colorado in 2013, the Asian-native beetle has yet to cross the Rockies, mostly due to a lack of ash trees in western forests, Davis said.
“It has a very slow spread, if any, in the West,” Davis said. But some of those who make their living selling insect prevention services believe the fight needs to begin now.
“I think we are at a really crucial juncture,” said Scott Taylor, the owner of Wasatch EcoCare, a tree care company based in Salt Lake City.
Taylor previously owned a tree care company in Ohio, the epicenter of the attack, and said he has treated more than 10,000 ash trees before, not losing a single one to emerald ash borers.
“The visual symptoms are uncannily similar to what I have seen before,” he said. “The things you have seen in Michigan or Ohio, they are already happening here.” Spears isn’t convinced. The ash borer is a weak flyer, she said, and thus is usually contained to a 10 mile radius around host trees.
“As of now it is considered a regulatory pest,” she said. “If we found them tomorrow, the Utah Department of Agriculture and Food and the U.S. Department of Agriculture would set up a quarantine so that no wood is allowed out of the area.”
Davis acknowledged it can be hard to identify emerald ash borers, as they tend to begin their attack in the tree’s canopies.
“They can be in trees for years and we would not know,” he said. “It is the people who are climbing trees and up in buckets doing work who are going to be the ones to first find it.”
As an arborist who does climb trees, Taylor said by the time researchers have physical evidence, trees will already be past the point of saving.
“If it goes on for too much longer, it will be too late,” he said. “That is what is frustrating. They don’t have to lose their trees, but it is likely they will.”
Telling signs of an ash borer infestation include D-shaped exit holes, where the adult beetle emerges, and meandering tunnels directly under the bark, where larvae eat their way through, Spears explained.
Ash trees in the West are mostly confined to urban streets, or parks where they have been planted, whereas the Midwest has full ash forests, Davis said.
“They are able to build up big numbers in the forest then sweep through the cities,” Davis said.
When emerald ash borers arrive in Utah, Davis said, they will have to jump from street tree to street tree. If left untreated, they will kill the ash trees in the cities within a few years.
“It is definitely discouraged to plant ash trees,” he said. “Our tax dollars would have to go to pay for these insecticides to treat trees that shouldn’t have been planted in the first place.”
Taylor said that the state governing bodies need to take action.
“They need to do one of two things,” he said. “They need to say emerald ash borer is here, or at least recognize there is something is happening to the ash trees.”
Taylor claims a treatment known as Tree-äge, or Emamectin Benzoate, is the only effective chemical he has seen in treating for emerald ash borer.
“I have done a lot of testing, and this stuff is extremely effective,” he said. Davis, however, said treating trees now would be a waste. “I don’t want people to be exploited,” he said.
Taylor said there are no hard feelings between him and researchers, just a difference in opinion.
“Ryan has been really cool, and he is very receptive,” Taylor said about Davis. “They need people like me, who are actually up in trees, to take photos and look for evidence.”
Taylor said he has not yet seen D-shaped exit holes or meandering tunnels under the bark of ash trees.
“Those are a year two thing,” he said. “In year one, they get premature leaf yellowing and canopy decline.” And that, he said, is what he is seeing — for instance in the Sugarhouse neighborhood of Salt Lake City.
Until they have a beetle, or have at least identified the exit holes on ash trees, Davis said there will not be a statewide response to treat for emerald ash borer.
—carter.moore@aggiemail.usu.edu
@carterthegrreat