Kennett Township at risk for Emerald Ash Borer infestation
● Published by Richard Gaw
Within a short period of time, all indicators point to the inevitability that an army numbered in the billions will invade Chester County.
In a fact-filled presentation before the Kennett Township Board of Supervisors on April 15, two members of the township's Environmental Advisory Council [EAC] said that Chester County is at a severe risk to lose its entire population of ash trees, due to the presence of an invasive beetle population that has already destroyed more than 40 million ash trees in the United States since first being detected 14 years ago.
At the request of the board, Matt Sabo and David Lewis of the EAC disclosed how the presence of the invasive insect known as the Emerald Ash Borer [EAB] could potentially and permanently destroy thousands of ash trees in the township, including more than 100 that are located in Anson Nixon Park in Kennett Square.
Typically, the EAB comes out in April-May and in June-July, the insect bores into the ash tree and makes deposits of eggs that morph into larval form, which then circumnavigate the ash tree and cuts off any nutrients that extend to the upper branches. It takes the insect about three years to entirely kill an ash tree.
“This insect is fatal to ash trees,” Lewis said. “Ninety-nine percent of the time, it will kill every ash tree. This is like preparing for an invasion from an army, and this is an army coming our way.”
Sabo said that the EAC originally thought that the presence of the EAB in the township would be a “modest problem,” but after tabulating the results of a local report, “we learned that it actually is going to be a significant problem in terms of quantitative size," he said. "There are many thousands of ash trees in our township, many of which are along public roadways or in public lands.”
Extensive ash tree decline was first noted in the greater Detroit metropolitan area as early as the summer of 2001, when the EAB was found on ash wood shipped from China. In response, the Michigan Department of Agriculture imposed a state quarantine in 2002 to regulate movement of ash nursery trees, logs, and related products from infested counties. USDA-approved eradication activities began in 2003, but were eventually terminated, as it became apparent that economic and technological constraints had rendered the objective nonviable. Despite these efforts to control the population, the EAB invasion continued eastward, and as of Sept. 2013, infestations have been detected in 21 US states and two Canadian provinces.
EAB was first found in Pennsylvania in 2007, when it was detected in Beaver County. Fifty six of 67 counties in the state have been infected. Chester and Lancaster counties are two of the remaining seven counties in Pennsylvania where EAB has not yet been detected, but that plans need to be made, “or we're going to lose a substantial portion of ash trees in our area,” Lewis said.
The environmental impact of such an invasion will be substantial. As ash trees die, Lewis said, the shaded areas of trees will become more visible and draw undesirable species of insects, as well as decrese the amounts of oxygen that healthy trees give off. It will be a professional problem as well, Lewis said; the township and other County municipalities would need to spend a lot of money to remove trees damaged by the EAB.
There are several possible solutions to holding off the appearance of the Emerald Ash Borer. Lewis said that both chemical injection treatments are available, as well as biological controls, seen in the presence of a parasitic wasps, who are a known natural enemies of the EAB.
"What no one is recommending is spraying," Lewis said. "What we eally want to do is contain the chemicals within the trees themselves and no allow them to the ground, which will give us a chemical run-off problem."
Tackling the problem will require the efforts of a full-time management team, and not just a volunteer effort, Lewis said.
It will be expensive, too. A cost estimate provided by Lewis and Sabo spelled out that it will potentially cost the township close to a million dollars to remove and replace all ash trees on or near township roads and Anson Nixon Park over the next 15 years: $320,000 to remove the damaged trees and another $626,000 to replace them. The replacement trees could take 25 to 50 years to become fully grown, Lewis said.
Lewis and Sabo asked for direction from the board in moving forward on possible solutions, as well as made some time-sensitive recommendations the EAC made. They include: establishing warning/detection devices on the township borders; establishing a task force [that includes those with forest management experience], a communication plan; reviewing and drafting a township ordinance that call for proper disposal and transportation of ash trees; identifying possible funding sources and partners; understanding the magnitude of the EAB problem in the township by determining the population density of ash trees; determine alternative approaches to eradicating the EAB; and providing the supervisors with quarterly progress reports.
“In terms of logistics, it's a large-scale problem and it's going to be a complex problem,” Sabo said. “There are a number of options the township may do, all the way from doing nothing to getting very proactive. Whatever the township plans to do, there is going to be a necessary component of dialogue with the community about what that decision is.
"This isn't any game," Lewis added. "This is for real. It's not something that we can just ignore."
To contact Staff Writer Richard L. Gaw, e-mail email@example.com.