May 07, 2013 | 03:42 PMLake Geneva is committed to saving 150 of its ash trees from the emerald ash borer.
Last year, the chemicals were purchased and the treatments applied to city-owned trees, said City Arborist Jon Foster.
Now, all anyone can do is wait.
"We'll see how they come out," Foster said in a telephone interview on Monday. That could take as long as two or three years, he said.
Last June, the city council voted unanimously to set aside $10,000 to save about half of the city's ash trees.
The treatments began this fall, Foster said in a recent telephone interview.
Fall application allows the chemical, a commercial insecticide called Treeage, to travel through the tree and kill the borers before they can do much damage.
The chemical is not cheap. According to information from the city's tree board, it costs about $495 per liter. Individually, trees receive an injection of 50 milliliters, for a cost of $25 per tree per application. According to city figures, add in equipment and labor and the cost per tree comes to $60.
But, by comparison, the city calculates that removing a 25-to-30 inch diameter tree costs about $2,000, not including a replacement tree.
Public Works Director Dan Winkler said the city might apply for a state grant this year to cover half the cost of the insecticide.
The city doesn't have many ash trees in its parks, Winkler said. Most are in the city's rights of ways.
While the city plans to treat 150 ash trees, another 150 ash trees will probably have to come down because they are too far gone with ash borer infestation.
Foster said the city took down between 30 and 40 trees this year.
"The rest we'll take down as needed," he said.
Foster said he's also looking forward to the state Department of Natural Resources' experiment with two species of imported stingless wasps.
The insects, not more than a millimeter long, are imported from China, and feed almost exclusively on the emerald ash borer's eggs and larvae.
Foster said the chemical treatments and importation of ash borer predators doesn't mean the ash borer infestation will be stopped.
But it may be slowed and allow many of the area's ash trees to live longer and healthier.
"It's going to take a few years to see how well this works," Foster said.
The program applies only to city-owned trees.
Private ash tree owners will have to find their own arborists to protect their trees. Foster told the tree board last week that he can give advice, but he's not licensed nor equipped to protect privately-owned trees.
Ash trees do not make up a majority of city trees. The city owns about 4,000 trees total.
Winkler has said the city stopped planting ash trees when news came out in 2002 that the emerald ash borer had been discovered in Detroit.
The pest has burned through the ash forests of Michigan, Indiana and Illinois. And although the invasion has slowed, it's still expanding.
So far, infested trees in Wisconsin have been identified in Brown, Crawford, Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, Vernon, Washington, and Waukesha counties, as well as Walworth county.
Foster found the first ash-borer infested tree in Lake Geneva in late May 2012.
But Bill McNee, DNR forest health specialist, said the ash borer is a stealthy pest and the beetles may have been in the area for up to two years before they were first detected.