Emerald Ash Borer infestation causes tree, budget problems
A small green insect, roughly the size of a quarter of a penny, is causing major environmental and budgetary issues for the City of Noblesville. Noblesville Urban Forester Paul Lindeman said the Emerald Ash Borer will be responsible for the city losing thousands of street trees and may wipe out an entire species.
“There are 5,000 ash street trees between the curb and sidewalks in Noblesville. After tree removal there will probably be less than one percent, if that,” he said.
Ash is the second tree species to be under attack from an insect – the first being Dutch Elm disease years ago. Lindeman said hybrid elms were developed which can withstand the Asian-based beetles.
“I’m not sure they’ll be able to do that in this case,” he said. “The Emerald Ash Borer is a really pesky insect. They lay larva into the bark and deplete the water and nutrients inside the tree. The adults exit the tree and attack outside the tree. It’s a two for one.”
Lindeman said ash trees were selected as street trees because they are fast growing, single trunk and do not have a “litter problem.”
“They are really good shade trees and native,” he said.
Ash trees were primarily used as the sole street trees in subdivisions built 10 to 15 years ago.
“There are a few that have hundreds of ash trees. They’re going to lose a couple hundred at a time,” Lindeman said. “Block after block of nothing left.”
Federal rules prohibit the planting of ash trees since EAB was discovered and in the past five years the city has incorporated tree diversity in new developments.
“Diversity is a real simple forestry principal. You have a better chance of having trees after infestation,” Lindeman said. “Diversifying 15 years ago would have helped on impact.”
The city has already had two wholesale subdivision removals. River Run has three trees, only one mature, after 53 ash trees were removed and The Meadows Estates has only a handful of trees left in its subdivision after 73 trees were reduced to stumps.
“Unfortunately that’s going to be a common thing in some other older subdivisions,” Lindeman said.
Lindeman said the city is replacing ash with trees similar in growth and branching habits. He said possible species include Japanese Tree Lilac, Green Vase Zelkova and Hybrid Elm.
The Legacy tree project has been treating trees for four years. Lindeman said treatments cost $99 per tree each year and treatment cycles are for five years.
“You have to do it every year once you start,” Lindeman said.
The treatments, which go into the roots and are carried up the tree, will prevent the bugs from damaging the trees. Lindeman said after the fifth and final year, the trees are safe if the insect has cycled out of the area. The Legacy program is treating 200 trees in Forest Park and across the city.
“All are doing well,” Lindeman said.
The biggest issue with EAB is detection.
“We don’t know if the insect is there and it is doing damage on the inside of the tree for up to two years,” Lindeman said.
Homeowners who are not sure if their trees are infected should look for signs or contact a professional to inspect the tree or remove it.
“They should think about starting over with a different species,” Lindeman said. “Once they move into a tree in any form, it’s done.”
The Noblesville Street Dept. is taking a proactive approach to its EAB problem. In an effort to spread the cost over a longer period of time, the department has created a 10-year plan for tree removal and planting.
“Unfortunately it comes down to being a financial burden that doesn’t fit into the budget,” Lindeman said. “We’re trying to stretch out costs for budgeting concerns. We have no budget for something this large.”
The department plans to replace 400 trees a year for 10 years. Lindeman said it is not known if all the trees will be planted in the spring or divided in half with spring and fall plantings.
“Winter, when we are not plowing snow, is the ideal time to do tree removal,” Street Department Director Patty Johnson said.
The estimated cost to Noblesville for its Emerald Ash Borer problem is $1.1 million. For 2014, $110,000 will be used from the city’s COIT Fund to pay $100,000 for tree planting and $10,000 for removal. Lindeman estimates an additional $110,000 will be needed for the next nine years.
“It’s more than what we normally do in a year,” he said. “We could be removing trees for two to four years.”
The basics – The Emerald Ash Borer
What is it? A wood-boring beetle that kills North American ash trees.
When did it get here? The beetle first arrived from Asia in wooden shipping material. It was first detected in the Detroit/Windsor area in 2002. Since then it has spread north in Canada and south into Indiana and Ohio. According to the USDA, the insect has been detected in Georgia, New Hampshire and Colorado.
How is it spread? Naturally – On its own, EAB moves slowly through the landscape, only about half of a mile per year. Human-assisted – People greatly accelerate EAB’s expansion when they move infested ash firewood and logs to new areas. EAB infestations outside of the Detroit area are the result of people moving ash firewood, nursery stock and logs.
What does it do? Starves ash trees of nutrients and water by tunneling under bark.
Is it harmful to humans? No. EAB is a threat to one species of tree and unfortunately has no natural predator to control the problem.
By the Numbers
25M – More than 25 million trees have been infected in the United States and Canada by the Emerald Ash Borer. “It’s spreading and going to keep going,” Noblesville Urban Forester Paul Lindeman said.
275 – It costs $275 a tree for labor and material.
2 – Only a handful of trees are left in River Run and The Meadows Estates subdivisions after two wholesale subdivision removals have taken place.
1:1 – Lindeman said trees will not be replanted for every ash tree removed due to overplanting. Most trees will be replaced but others will be spaced out in large areas.
1 – Noblesville will likely have less than 1 percent of its 5,000 ash street trees due to EAB.