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
ALGIS LAUKAITIS / Lincoln Journal Star | Posted: Sunday, November 25, 2007 6:00 pm
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.
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.