Asian longhorned beetles are latest to assail our forests

Would the Asian longhorned beetle be less frightening if someone had found one here, infesting the local maples, elms or ash trees? It’s  hard to know if an invisible and perhaps imminent threat is more terrifying than a concrete enemy that one can see and fight, and take action against.

Whatever the answer, one thing is certain: The threat of these invasive insects has tree professionals in the area spooked and nervous. Aggressive efforts are being made to make sure they don’t invade the forests of Litchfield and Berkshire counties.

And it’s not an easy task. These black-and-white, inch-long beetles live deep inside trees (their favorites are maples, but they’ll settle for ash or elm; they don’t, however, seem to like oaks or conifers, according to one area tree expert).

Some believe the insects are here, eating away at the hardwood hearts of their host trees. Scott Monroe of Sharon-based Monroe Tree Company believes it’s absurd to think that the beetles, which have been found in New York City and in Worcester, Mass., are not here as well.

“I have no doubt they are here,†he said, and he is advising his clients that if there are some trees that they particularly treasure, they ought to think about treating them with pesticide — especially if they have not yet been infested.

“It’s like the flu shot,†he said. “Once you get the flu, it’s too late to get the shot. When it’s noted, when you’re aware of it, it’s often too late to treat. That’s the way it is in nature.â€

Tom Zetterstrom of North Canaan has nurtured many elm trees in the Northwest Corner in recent years, but he isn’t treating them. He’s convinced that the beetles have not invaded the Litchfield hills yet and he is not planning to apply pesticides.

“There have been no reported cases of Asian longhorned beetle in Connecticut, so treatment for a disease that is not present in our area is not a good use of our financial resources,†he said.

He also expressed some concern that overuse of pesticides can create resistance “in the targeted pest.â€

“Elm Watch has planted 150 elms in public places in two dozen towns in Berkshire and Litchfield counties,†he said. “We monitor these trees for good health†and have not seen any signs of the beetle, even though elms are a potential host tree.

“We will remain alert to any signs of beetles in our area.â€

Jody Bronson is the forest manager for the Great Mountain Forest, a 6,041 acre working forest in the towns of Norfolk and Falls Village that is comprised of many of the trees the beetle likes best — especially maple trees, which produce sap each spring for gallons of maple syrup.

At this point, he said, he is more concerned with emerald ash borer, another invasive insect that he said “moves at a much faster rate and will be devastating to the ash trees in Connecticut.

“However, we are aware of and concerned about the Asian longhorned beetle.†But, he added, “they are poor fliers and do not travel far. The best precaution is: Don’t move firewood! Do not bring firewood in from outside sources, buy wood that was cut locally. Both the emerald ash borer and the Asian longhorned beetle are more likely to enter Connecticut from firewood that has entered from out of state.â€

The longhorned beetle is believed to have entered the United States in wood palettes carrying cargo here from Asia. So far, it seems to have mainly infested trees near industrial areas — a recent inspection of Litchfield County trees focused on industrial sites in Torrington. Although no beetles were found there, meaning that no imports have infected the local forests, there is still a chance the beetle has been carried down here from the Worcester site, where 25,000 trees were cut down last year.

“There is great concern that someone  since then has moved the beetle from Worcester to the Berkshire hills, along with firewood,†said Frank Lowenstein, director of forest health for North America for The Nature Conservancy. He works from the Sheffield, Mass., office of the conservancy.

In literature about the beetles from state and federal environmental agencies, the number one request is that people not move firewood, because it might contain the bugs.

Landowners can also keep an eye on their trees and look for some of the signs that beetles have taken up residence.

“The way you detect it is by looking for the signs the beetles and the larvae leave behind,†Lowenstein said.

The exit holes of the larvae, after they have eaten their way through your tree, are dime-sized, large enough that you are likely to notice them.  

“They emerge straight out of the tree,†Lowenstein said. “You can put a pencil in the hole and it will be perfectly perpendicular.â€

Other signs include sawdust in the notches of the trees and smaller holes where the female has laid her eggs.

Don’t look for signs of ill health in the tree, all the tree experts agreed.

“Your tree will look fine on the outside,†Lowenstein said. “Until the day it collapses.â€

That’s a thought to send shivers down the spines of tree lovers. Here’s another one: “Picture your favorite mountain, and picture it covered with dead maple trees, dropping dead branches on every trail,†Lowenstein said.

If it is not caught in time, there is a chance that this infestation will be as deadly to local trees as previous plagues that have wiped out entire species locally, such as the Dutch elm disease in the 1940s and the chestnut blight in the first few decades of the 20th century. The federal government is now taking aggressive action, and will sometimes hire arborists to cut down all the trees in a specified radius of an infected specimen.

“As long as they think we are in eradication mode, the federal government will continue to cover the cost of cutting down trees,†Lowenstein said. “Take the emerald ash borer, as a warning of what might happen. The borer has now spread across large portions of four states and small areas of others. The federal government has said there is no chance of eradicating this, so we won’t pay for it anymore. So now there are 25 million dead ash trees in yards and on streets that are the responsibility of homeowners and municipalities.â€

To avoid the worst case scenario, Lowenstein recommends a visit to the dontmovefirewood.org Web site, which he promises has some “amusing videos.â€

And, he said, “let your congressional delegation know that our trees are important to us and these programs to fight these invasive pests need to be well funded. Part of what’s delaying eradication is a lack of funding; and part of the reason why the ash borer got out of control to the point where no one believes it can be eradicated is we didn’t put forward the resources to fight it.â€