The emerald ash borer, believed to be the most destructive insect to afflict trees in North America, has been found for the first time in Nebraska.
The Nebraska Department of Agriculture confirmed Wednesday that the invasive beetle is in Pulaski Park in South Omaha.
The infestation is probably in its early stages, because foresters and arborists have been searching for signs of the beetle for several years and haven’t found any, said Graham Herbst, the eastern Nebraska community forester for the Nebraska Forest Service.
How established the beetle is matters, because that will determine how quickly the infestation marches through metro Omaha.
The beetle can kill all untreated ash trees, young or old, healthy or weak — which would be devastating, because ash are among the region’s most plentiful, sturdy native trees.
“We have suspected for a while that it’s in the area,” Herbst said. “It’s one of those things: We really wanted to find it and really didn’t want to find it at the same time. What’s to come is not pleasant.”
Foresters estimate that about 14 percent of trees in Omaha are ash. In some neighborhoods, such as Regency in west-central Omaha, they are the dominant shade tree.
“Throughout Regency, you have a canopy of ash trees,” said Gene Pace, vice president of the Regency Homes Association. “In the summer you drive though there, and it’s all shaded by ash trees.”
He has been watching the ash borer spread across the country toward Omaha and his neighborhood. He has researched plans to treat his own three ash trees and hopes that the neighborhood will invest to treat the trees in common spaces.
Nebraska, which has an estimated 44 million ash trees, is the 27th state to confirm the presence of the emerald ash borer, the State Department of Agriculture said.
Eventually, the infestation here is expected to cost state and local governments, homeowners and businesses nearly $1 billion to cut down and replace ash trees. Add in the expense of treating trees, and the pest will cost even more.
Communities around Omaha are weighing their options. In some, like Papillion, ash trees make up 25 percent of the canopy. Council Bluffs already has begun treating many of the ash trees that it wants to preserve and has removed the most sickly ash trees on public property, Parks Director Larry Foster said.
The Nebraska Department of Agriculture issued a quarantine for all of Douglas, Sarpy, Cass, Washington and Dodge Counties. The quarantine prohibits ash tree nursery stock from leaving the area, and it covers green ash lumber and any parts of ash trees, living or dead. It also prohibits moving any firewood, wood chips or mulch, of any hardwood species, out of the area.
In the 14 years since the first North American discovery of the borer, in Michigan and Ontario, the beetles have killed hundreds of millions of trees, mostly in the eastern United States. The rapid advance of the insect across the country is blamed on the transport of infected firewood and nursery stock.
If there’s any good news for those in Omaha, it’s that the ash borer has been the subject of furious research. Homeowners today have better treatment choices than they did in the first wave.
Treatment options involve injections, drenches and sprays, said Mark Harrell, forest health program leader for the Nebraska Forest Service. Treatment is best done in mid-May to early June, he said, which means the window is nearly closed for this year.
But it’s not necessarily a death sentence for a tree not treated this year, Harrell and Herbst said.
The emerald ash borer is limited in how far it can fly, so the beetles in Pulaski Park aren’t expected to cause widespread harm immediately. At best, the beetles there will be able to fly only a few miles. Most will stay in the vicinity of the park at 40th Avenue and H Street.
“It probably hasn’t spread very much because there’s so much material for it to feed on right where it is,” Herbst said.
On the other hand, foresters don’t know whether Pulaski is at the heart of the infestation or on the edge. So it’s not possible yet to define the boundaries of the beetles’ reach.
Though no other findings have been confirmed, the beetle could be in other areas of metro Omaha or elsewhere in Nebraska.
Herbst said local and state foresters teamed up last year to search logical areas of metro Omaha — and found none. Logical areas are along interstates and highly-trafficked tourist sites such as the Henry Doorly Zoo, he said, areas that receive lots of travelers and recreation vehicles hauling firewood.
In Omaha, evidence of the beetle was found, ironically, during a press conference to announce the city’s plans to battle the insect:
On Friday, a city Parks Department crew cut down a diseased-looking ash tree in Pulaski Park to provide the public with an example of the type of trees that it will remove under its beefed-up response plan.
A worker peeled back the bark of the tree, standard procedure when cutting down an ash, Parks Director Brook Bench said. When the wood was laid bare, arborists on hand realized that the moment of reckoning had arrived, said Herbst, who was there.
“There were some expletives and some gasps,” he said.
The tree’s trunk bore the tell-tale squiggles of the larvae of an emerald ash borer.
Confirmation of the emerald ash borer continues a string of disappointing news for Nebraska’s trees.
Pine wilt already has wiped out most of Nebraska’s Scotch pines. The Missouri River flood of 2011 killed many of the trees in the river valley along the state’s eastern border. And drought has thinned the already thin canopy in the heart of the state.
If Nebraska is to continue to have a vibrant stock of trees, it will need to undertake an effort equal to the threats the trees are facing, said Eric Berg, community forestry and sustainable landscape program leader for the Nebraska Forest Service.
This includes planting a greater diversity of trees than has typically been the case, he said.
Complicating the matter is climate change, he said. Nebraska’s climate is shifting rapidly, and it’s not clear what type of tree will survive and thrive.
The average temperature is rising, the growing season is lengthening, and Nebraska is expected to become more vulnerable to extreme drought and extreme precipitation, research has shown. Although the increasing warmth would seem to make the state more hospitable to southern trees, that’s not a given, Berg said, because Nebraska remains prone to deep freezes in winter that would kill them off. Further muddying the issue is the widening variety of pests and disease moving into the area with climate change.
So while Nebraska is experimenting by planting trees from the Southern Plains, it’s also looking at those that thrive in northern states — and from other areas of the globe, particularly China, that have a similar climate, Berg said.
“We don’t have a good solid answer for that, so the answer is going to be, let’s plant a lot of different types of trees,” he said.
World-Herald staff writer Christopher Burbach contributed to this report, which includes material from the World-Herald News Service.
Contact the writer: 402-444-1102, email@example.com
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Most definitive website on emerald ash borer (Multinational, academic and governmental): http://www.emeraldashborer.info/
Nebraska Forest Service guide to emerald ash borer: http://nfs.unl.edu/nebraska-eab
Consumer guide to emerald ash borer: http://www.emeraldashborer.info/documents/Multistate_EAB_Insecticide_Fact_Sheet.pdf
USDA emerald ash borer hotline, toll-free at (866) 322-4512
Watch the Nebraska Town Hall: http://nfs.unl.edu/watch-eab-town-hall-0