Forester: no emerald ash borer yet

Published 10:00 am Wednesday, May 26, 2010

Despite any speculation around Albert Lea that ash trees are dropping their leaves because of an emerald ash borer infestation, local Parks Superintendent Joe Grossman said he does not think this is the case.

Grossman is the city forester.

He said many ash trees in town sustained frost damage a couple weeks ago during the area’s cold spell and a few may have an anthracnose disease, which is a disease caused by a fungi that attacks the trees.

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Either of these problems could cause defoliation, or the removal of leaves. Also, with winds approaching 30 mph or more over several days, the trees are drying out.

It’s a problem that’s taking place not just in Albert Lea but across southern Minnesota and northern Iowa, as well, he said.

The best thing people can do if their trees are defoliating is to water them, and eventually they will grow new leaves.

He said the closest the emerald ash borer has been reported to Albert Lea is in St. Paul and Minneapolis; however, it is only a matter of time until the invasive species is brought into Albert Lea.

According to the Associated Press in March, the emerald ash borer, a metallic-green, invasive beetle, has already killed more than 40 million ash trees nationwide and in Canada. The beetle’s larvae tunnels into the wood of ash trees and feeds on the inner bark.

They are active from May to September and leave signs of infestation such as one-eighth inch, D-shaped exit holes in ash tree bark and serpentine tunnels packed with sawdust under the bark.

Emerald ash borer prompts firewood concerns

The larvae kill ash trees by tunneling into the wood and feeding on nutrients between the bark and the hardwood. While they spread slowly on their own, the beetles can also spread to new areas when people transport firewood or other wood products infested with the larvae.

“Unfortunately I don’t think people realize how devastating this is going to be,” Grossman said, noting that it has the potential to be worse than the effects of the Dutch elm disease that struck in the 20th century.

In a Tribune article in April of 2009, Grossman estimated ash trees make up probably 25 to 30 percent of the total community forest. Many of these were planted during the 1970s and 1980s.