City officials confirmed the presence of the invasive beetle known as the the emerald ash borer in the Madison area, posing a serious danger to the local tree population.
Donna Gilson, Wisconsin Department of Agriculture, Trade and Consumer Protection spokesperson, said the green, half-inch long beetle gets its name from “boring into ash trees.” In midsummer, adult beetles lay eggs in the bark of the ash tree, Gilson said. She said tiny, worm-like creatures emerge and burrow between the bark and the wood of the ash tree, where they start to eat.
“[It goes into] the tree’s vascular system, really. It’s where the water and nutrients come up [from the soil to] the tree, and so it disrupts the tree’s ability to feed, and kills the tree within three to four years,” Gilson said.
Gilson said the problem is the emerald ash borer has the ability to spread from one ash tree to another, and this threatens the entire ash tree population in an area.
Phillip Pellitteri, an insect identification and insect and tick biology expert at the University of Wisconsin, said in an email to The Badger Herald the beetle is a serious threat to local plant life.
“The simple answer is over time it will kill all untreated ash trees, so the impact will be similar to what dutch elm disease did 40 years ago,” Pellitteri said.
Dutch elm disease, according to Gilson, affected many areas of the United States 40 to 50 years ago. Many elms were infected and died, and most were replaced by ash trees, because ash trees grow fairly quickly and beautifully, she said.
“Well, what they found out later was that planting a lot of one species like that, it’s a problem [because] the pests can spread pretty easily,” Gilson said. “And the reality is once it has taken hold in a tree, there’s not really a way to stop it. The tree is going to die, and it’s expensive to take trees down.”
Gilson said losing ash trees causes no major environmental problems, but can pose problems to the city budget for tree treatment and replacement.
Losing trees could also hurt resale of homes and bring down property value, Gilson said.
“They reduce your cooling cost in the summer time. They can give shelter and actually reduce some of your heating cost in the winter,” Gilson said. “They keep the pavement from getting so hot, keep the cities from being so hot. So trees in general have a lot of benefits, and when you have so many of them in one species [and] lose them, you’ve got a problem.”
Madison currently offers several different ways to deal with emerald ash borers, according to a city statement. Recommendations include chemically injecting trees to keep the beetles at bay, preemptively removing ash trees in poor condition and replacing the removed trees within the next year or planting season.
Though Madison can use these methods to combat the threat of the emerald ash borer, they still will not save many of the ash trees within the city.
“It may be 20 years before [we] have big trees again,” Gilson said.