The emerald ash borer is so deadly, foresters and bug experts fear that if it's left unchecked, it eventually could wipe out every ash tree in the United States. The half-inch-long beetle doesn't affect other trees.
The discovery of the bug was confirmed in Carmel this week. It also may have made its way into adjacent townships in Marion County.
With its rounded crown and vibrant gold fall color, the ash is a popular street and yard tree. Since the bug was discovered in Detroit in 2002, infestations have led to the destruction of more than 15 million ash trees in Michigan, Ohio and Indiana.
In an effort to slow the insect, the state imposed a quarantine Friday on Clay and Delaware townships in Hamilton County and Washington and Lawrence townships in Marion County. The move means no ash trees or firewood of any kind can be moved into or out of the townships. A less-stringent quarantine for the counties, which would let people move ash out of the area with state permission, also is likely, said Robert Waltz, state entomologist.
Officials say the Carmel infestation -- detected so far in about a dozen trees along Hazel Dell Parkway just north of 96th Street -- has such a big head start that there is no telling how far it has gotten. The DNR also is investigating a suspected infestation in Fishers and expects to find the bug in Marion County, too, Waltz said.
Carmel has about 14,000 street trees and untold thousands of additional trees in the yards of homes, Carmel forester Scott Brewer said. About 15 percent of the trees are believed to be ash.
Officials believe the Carmel infestation is at least 7 years old, meaning it began before anyone in the United States knew the beetle existed, said Jodie Ellis, a Purdue University insect expert.
The dark metallic green beetle lays eggs on the bark of ash trees. When the larvae hatch, they burrow beneath the bark and feed on the tree's vascular tissue, the systems that carry water and nutrients. Infested trees starve to death within one to three years. Once a tree is infested, there is no way to save it.
Carmel's beetles are suspected to have come from nursery stock that originated in Michigan, officials said. The city planted hundreds of ash trees along the roadway in 1999. A landscaping company bought the trees from a nursery in Ohio, Brewer said. He said it also is possible that the beetle arrived on other trees or on firewood, then spread.
On its own, the beetle, which can fly, moves about a half-mile a year. But it has spread much faster through deliveries of infested firewood and trees.
Ellis said she was not surprised that the ash borer was found in the area. "(It) is a booming town; there is a lot of building and landscaping going on, and ash is a great tree."
Carmel has a "Tree City USA" designation, and the nonprofit group Citizens for Greenspace has planted more than 4,000 trees since 1989. But it stopped planting ash trees four years ago because of fears about the ash borer, said Sue Dillon, the group's co-founder.
"This is a disaster if they can't find some way to control it. So much of our hardwood forests in Carmel and Indiana are ash," Dillon said.
Ash constitutes about 6 percent of the state's forests, 70 percent of which are south of Indianapolis. There are an estimated 147 million ash trees in Indiana forests and perhaps an equal number in cities.
More than 118,000 ash trees already have been cut down in Indiana's infested areas.
Until now, the beetle had been found in four counties in Indiana -- Adams, LaGrange, Randolph and Steuben -- near the Michigan and Ohio borders. DNR officials hoped they could contain it before it spread to urban areas and the state's southern forests.
But the new infestation made two things clear: The bug has a much stronger hold in the state than thought, and officials have no way of knowing where it will show up next, Waltz said.
The state's policy had been to cut down every ash tree within a half-mile radius of an infestation. The state has received $1.8 million from the U.S. Department of Agriculture to fight the infestation, but that's not enough to do the job. Also, cutting doesn't seem to make much sense because the Carmel infestation proved officials don't know where the beetle is, Waltz said. Now, only infested or dangerously damaged trees will be cut.
Ellis said cutting trees around infestations would have bought the state more time, but "we have to deal with realities of our budget."
The best hope, officials said, is that researchers can introduce a natural predator to control the beetle or develop an effective chemical control. Some researchers are working on improving methods to detect the beetle. Others, including those at Purdue, are working to develop ash trees with a natural resistance to the pest, Ellis said.
In Carmel, it is likely that many, if not all, of the city's ash trees eventually will be killed by the beetle and have to be cut down, Ellis said.
"It could take decades or, with the right weather, it could explode and kill them all in three years."
The city will remove infested street trees. But property owners will have to remove their own trees if they become infested or die. Homeowners who cut down infested trees can burn the wood but cannot give it away, Waltz said.
DNR Director Kyle Hupfer warned residents to be on the lookout for scam artists who may offer to treat their trees with pesticides, which he said don't work.
"Nothing protects ash trees," he said. "But fertilizer and water can help keep them strong."
Carmel resident Gary Doxtater, who is on the Indiana Wildlife Federation board of directors, said, "You can plant more trees, but it takes 40, 50 years to replace them."
Waltz said the best way to immediately fight the bug is to teach people not to move infested trees or wood. "If we fail to control the people aspect, then all bets are off."
Call Star reporter Tammy Webber at (317) 444-6212. Star reporter Lesley Rogers-Barrett contributed to this story.
WHAT YOU NEED TO KNOW
Is my tree an ash?
Ash trees have a featherlike leaf, usually with five to nine leaflets. Branches are opposite one another, not alternating.
Is my tree infested?
Look for a D-shaped hole created by the beetle larvae.
If it is infested, do I have to cut it down?
No, but the city could recommend cutting it down later.
How can I get rid of my tree?
If the tree is large, call a licensed arborist. You can burn the wood in your fireplace but cannot give it away. Otherwise, it must be ground into pieces less than an inch.
Who pays?
Local governments will pay to cut down trees on municipal property. Homeowners must take care of trees on private property. Arborists may charge anywhere from $50 to remove a 2-inch-diameter tree to $1,000 or more for a large tree.
Can an infested tree be saved?
No. There is no effective treatment at this time.
Sources: Carmel city forester Scott Brewer, Star research
ASH TREES AND THE EMERALD BORER
About ash trees
There are 147 million ash trees in Indiana forests. More than 6 percent of all forest trees in Indiana are ash.
There are at least 1.5 million ash trees in Indiana's urban areas. In some urban settings, 40 percent of the street trees are ash.
In North America, the emerald ash borer attacks all types of ash trees, including Green ash, White ash and Black ash, as well as all other horticultural varieties of the tree.
About the emerald ash borer
The emerald ash borer (agrilus planipennis Fairmaire) is an exotic beetle. The metallic coppery green insect is about 1/2-inch long.
It is suspected the beetle arrived in the United States on wood-packing material aboard cargo ships or via air from Asia. It was discovered in the Detroit area in the summer of 2002 and found in Ohio in 2003 and Northern Indiana in 2004.
Adult beetles eat ash foliage but cause little damage. The larvae feed on the inner bark of ash trees, blocking the movement of nutrients and eventually killing the tree.
The infestation has led to the destruction of more than 15 million ash trees in Michigan, Ohio and Indiana.
Quarantines and fines have been used to prevent infested trees, logs or firewood from moving out of areas where the borers have been found.
The borers have cost tens of millions of dollars in damage to municipalities, property owners and forest-products industries.
To learn more
•
http://www.emeraldashborer.info/ -- A collaborative effort of the USDA Forest Service, the Michigan Department of Agriculture, the Michigan Department of Natural Resources and USDA Animal and Plant Health Inspection Service and Michigan State, Purdue and Ohio State universities.
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www.entm.purdue.edu/EAB/ -- Includes information on the emerald ash borer in Indiana.
Sources:
•
www.emeraldashborer.info
•
www.entm.purdue.edu/EAB/
-- Compiled by The Indianapolis Star's library
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