CLINTON – Not everyone at the Bickelhaupt Arboretum can remember what happened to local horticulture in the late 1960s. They’ve all heard stories, though, about how Dutch Elm Disease laid waste to scores of trees across the Midwest.
Now another infestation threatens the region. The pest known as the Emerald Ash Borer (EAB) has been found as close as Morrison, Ill. Within the next three to five years, local experts believe the insect will find its way across the Mississippi River, and the looming destruction is expected to “far surpass” what happened more than four decades earlier.
“They think there are eight billion ash trees in North America,” said Margo Hansen, director of programs at the Arboretum. “Back in the 60’s, we used to have these streets that were all canopied by elm trees, and they all died because of Dutch Elm.
“The problem (with EAB) is that it’s real small – smaller than a penny. And once it gets in the tree it’s too late.”
In February, a quarantine was placed on all of Iowa’s 99 counties that prevents moving wood that might be infected, like entire ash trees; firewood of any hardwood species; or any cut or fallen material of the ash, with the goal of slowing the Emerald Ash Borer’s spread.
The Clinton Tree Commission also is beginning a push to inform citizens about EAB dangers. Local agencies have begun implementing procedures they hope will prevent a widespread outbreak.
The borer – a native insect of Asia -- was rumored to be introduced to Michigan in 2002. It has since made a steady migration to the Midwest and upper East Coast. The creature only borrows into ash trees, which are common in the Midwest due to their previous landscaping-friendly nature.
Hansen explained that Dutch Elm Disease was a fungus that grew within trees and blocked water circulation or “clogs the trees’ arteries.” The EAB, instead, borrows into the wood, severing the veins, cutting off water and killing trees over time from the top down.