Emerald ash borer could destroy over 2 million trees

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By ALGIS LAUKAITIS / Lincoln Journal Star

The emerald ash borer is a  metallic green bug with a voracious appetite for healthy ash trees.

The insect, commonly called EAB, already has killed more than 25 million trees in Michigan, Illinois, Ohio, Indiana, Pennsylvania, Maryland, West Virginia and Ontario, Canada.

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Adult emerald ash borers emerge from an infested ash tree (Fraxinus pennsylvanica). (Deborah Miller)

Is it emerald ash borer?



Some Nebraskans have already lost trees to what they thought was emerald ash borer.

"There already have been some trees taken down by mistake in Nebraska because the homeowners were told their trees had emerald ash borer," said Mark Harrell, Nebraska Forest Service Forest Health program leader.

"None of these trees were infested. If homeowners are told they have emerald ash borer, they may want to contact another certified arborist or other tree care professional to get a second opinion," Harrell wrote in a news release.

Experts from the state Forest Service, U.S. Department of Agriculture Animal and Plant Health Inspection Service, and Nebraska Department of Agriculture are trained to recognize emerald ash borer, or EAB, and can determine whether the insect is present.

Because EAB only attacks ash trees, a person should be sure the tree in question is an ash and not a similar-looking species.

If a tree is infested with EAB, it must be removed to help prevent the insect from spreading.

In urban areas, trees may be near utility lines, homes or other buildings, so it is often best to have the tree removed by a certified arborist.

Reputable arborists will be able to provide proof of insurance and references, as well as written documentation of the work to be done.



Emerald ash borer

What is it? A metallic green insect with a flat back that attacks only ash trees. Adults are about a half-inch long.

How did it get here? Scientists believe the insect came to the U.S. from its native Asia in wood packing material aboard a cargo ship or airplane.

Where is it found? The emerald ash borer has been detected in Michigan, Indiana, Ohio, Illinois, Pennsylvania, Maryland, West Virginia and Ontario, Canada, making it a national pest problem.

How many trees has it killed? More than 25 million so far.

Is it in Nebraska? No emerald ash borers have been detected in the state. Officials cannot predict if or when the insect will appear here.

What are some EAB symptoms on ash trees? They include winding tunnels under the bark, D-shaped exit holes on the trunk, as well as canopy loss, usually from the top down. Other symptoms include vertical splitting in the bark and increased woodpecker activity.

Who do I call if I think my tree has EAB? Call the city forester's office at 441-7036 or the Nebraska Forest Service office in Lincoln at 472-2944.

Where can I get more information? www.nfs.unl.edur www.emeraldashborer.info

And federal, state and local forestry officials fear it will make its way to Nebraska and other Great Plain states.

“It may already be here,” said  City Forester Steve Schwab.

The  emerald ash borer was first detected in southeast Michigan in 2002, Schwab said, and scientists discovered it had been in the state for eight years.

If and when EAB comes to Nebraska, officials say, the state could lose an estimated 2.2 million ash trees.

The cost to remove and replace these trees could exceed more than $1.5 billion. It also could result in the loss of what trees do: provide shade, filter air and water and protect streets and highways.

“It will be similar to Dutch elm disease in the 1960s, which rapidly killed millions of trees in Nebraska and dramatically converted lush urban forests to barren, shadeless urban landscapes,” State Forester Scott Josiah said in a news release.

Lincoln could lose between 100,000 and 120,000 ash trees, Schwab said — 25 percent to 30 percent of the city’s trees.

City Parks and Recreation Director Lynn Johnson recently told Mayor Chris Beutler it would cost about $38 million to remove and replace 30,000 ash trees on city property.

Bug hitches rides

Experts believe the Emerald ash borer, which is native to Asia, arrived in the U.S. in wood packing material carried in a cargo ship or airplane.

Adult insects nibble on ash foliage but cause little damage, foresters say.

However, the larvae feed on the inner bark of ash trees, disrupting the trees’ ability to transport water and other nutrients. The exotic insect only attacks ash trees.

There are no effective measures to prevent the spread of the borer, said Steve Rasmussen, a district forester with the Nebraska Forest Service, based in Wayne.

“It isn’t selective. It kills all ages, all sizes, and all species of ash trees,”  Rasmussen said.

Green ash trees are the only ones native to Nebraska. But other species — like white, black and purple ash — have been planted in the state. Foresters say all ash tree species are at risk.

The good news? The insect only moves about a half-mile to 2 miles a year on its own, Rasmussen said.

The bad news? The insect can “leap frog” large areas by catching rides in firewood and wood products.

Firewood inspections

Quarantines are in place in many states to prevent infested ash firewood, logs or nursery trees from being transported and starting new infestations. Violations could result in fines.

Nebraska has no restrictions, but officials are asking people to not haul ash firewood, especially if you go camping or deer hunting.

Last year, the state Department of Agriculture began to randomly inspect firewood across Nebraska, said state entomologist Julie Van Meter, and has found no evidence of EAB.

Staffers inspect wood at gas stations, groceries, nurseries and other outlets, she said. Her five-person staff looks for not only EAB but also for other pests and diseases.

“Firewood is a big issue. It gets us out there looking at what is coming in and seeing it,” Van Meter said. “We’re happy to see a lot of firewood is of Nebraska origin. But there is a lot of firewood coming in.”

More than a year ago, the state formed the Emerald Ash Borer Working Group. The group, made up of federal, state and local officials, is looking at ways to prevent EAB from entering the state and strategies to deal with it if it arrives.

Nebraska was the first state to require origin labeling on nursery stock, Van Meter said, two years before Michigan detected EAB.

Under the program, the state’s 1,100 licensed  nursery dealers and growers  are required to code tree stock and provide annual lists of their tree providers.

States team up

Foresters are asking people to plant species other than ash. The goal: Create diversity, so if the borer arrives, damage would be less.

Spraying ash trees won’t do any good because there is no evidence the insect is here, Rasmussen said.

“Our hope is before it gets across the Midwest, we find ways to stop it,” Rasmussen said.

Injections for ash trees are available to combat EAB, Van Meter said,  but they must be done every year and could get expensive. And there are no guarantees it will stop EAB from killing a tree.

Researchers are looking at control methods, including insecticides and parasitic wasps. Meanwhile, they’re trying to raise awareness about the potential threat, which has become a national problem.

With the help of a $1 million grant from the U.S. Forest Service, the Nebraska Forest Service, in partnership with forestry agencies in Kansas, South Dakota and North Dakota,  are working on an initiative to prepare for the insect’s arrival.

All four states plan to survey ash tree resources, including locations and condition of trees. They also will distribute more information.

Finally, they plan to find uses for the millions of ash trees that may have to be cut down. Burning the trees as biomass  to produce energy is one possibility.

Reach Algis J. Laukaitis at 402-473-7243 or alaukaitis@journalstar.com.