Ash to ashes

An iridescent Asian beetle that has killed tens of millions of ash trees in the Midwest has taken hold in New York, home to more ash trees than any other state, and it’s likely nearly every one of them will die.

The emerald ash borer, first seen in southeastern Michigan and Windsor, Ontario in 2002, turned up this year in several New York counties, including Ulster County at a Saugerties campground and on private land in Catskill, Greene County. Though individual trees can be protected with injections of pesticide, experts say in all likelihood, every other ash tree will die. When scientists talk about long-term solutions, like fostering immunity in North America’s ash trees and introducing natural predators, they’re talking about after the majority of New York’s ash trees have been destroyed. And at this point, it’s far from inevitable that these methods will work.

Mark C. Whitmore, a forest entomologist with Cornell University’s Department of Natural Resources, said extinction is a real possibility. “Nothing like this has really happened in my mind,” he said. “The potential of losing a species is very dramatic and virtually unprecedented in North American history. You think about the chestnuts disappearing, well there’s still chestnuts out there…The same is true of elms, with Dutch elm disease. There’s still a lot of elm trees out there. The big ones are gone and it was very dramatic losing them, but we still have the gene. With the ash, we’re looking at perhaps losing a species.”


Calling Ulster County the “frontlines” in the fight against the insect, on August 11 U.S. Senator Charles Schumer called for $1.25 million in emergency federal money to fund bio-control, outreach to municipalities and education efforts. Schumer’s release identifies the victims of the borer as towns with ash-lined main streets, and the furniture, lumber and sporting goods industries. He quotes data from the Western New York Partnership for Regional Invasive Species Management, which estimates the cost will be $10.7 billion for treatment and removal in urban and residential areas in the U.S. over the next 10 years.


Preparing for the Ash tree loss

With nothing standing in its way, the borer will naturally fan out over North America from its Great Lakes epicenter. But people are speeding up the process, particularly people who transport firewood more than a few miles, and as such the DEC and wildlife management experts have stressed the need for New Yorkers to burn firewood as close to where it was cut down as possible. (Anyone who’s gone camping on public land recently has likely had this conversation with a forest ranger.) Much of the federal money, if secured, will go toward getting this message out. More than anything, compliance here will help slow down the spread of the insect, and give people and communities time to prepare.

“The first question I’d ask any community elder is: Do you know how many ash trees you’re responsible for as a community?” said Whitmore. “And there aren’t very many that do…Once a community has an idea how many trees they have to deal with, then they can begin making plans for what they’re going to do with them.”

Whitmore said it’s necessary to determine which trees will be protected and which will be removed, and come up with a plan to avoid having a massive die-off of ash trees in areas where falling branches pose a hazard. “One of the biggest problems in the Midwest is that communities were faced with having to remove thousands of ash trees very quickly because of liability issues and they hadn’t planned for that monetarily,” he said.

Emerald Ash Borer larvae feed on the tree's nutrients.

Other communities did prepare, placing line items for tree removal and replacement at a reasonable rate each year, and large cities like Chicago and Milwaukee recently announced plans to treat a large number of trees. The same principle holds true for homeowners and businesses: identify how many ash trees you’re responsible for, and make a decision. If you’re within 15 miles of West Saugerties, you’re in the range of the borer, says Whitmore, who suggests residents and local government officials contact the local Cornell Cooperative Extension target=”_blank” and DEC offices, which have ramped up into high gear since the borer’s emergence here.


What will the ecological consequences be of losing so many trees? Whitmore said it’s hard to say at this point, though ash trees do play an important role in recolonizing formerly cleared tracts of land, and serve as sources of food and shelter for many animals.

Selective Innoculation

How feasible is protecting ash trees with pesticides? The most effective pesticide is called Tree-äge™ (emamectin benzoate), which is injected into the tree’s circulatory system every two to three years. Brennan Donohue of JP McHale Pest Management, Inc. in Buchanon, New York, said it makes sense in many cases to protect rather than replace, particularly for a small number of prominent ash trees. “If you have five ash trees around your home, and we all know trees add value to your home, so if you lose them it’s going to cost a couple thousand dollars to remove them, and that’s a couple thousand dollars lost against the value of your home, and it only takes a couple hundred [dollars] to treat the trees every couple years, so it just makes sense to do.”

According to information provided by Donohue, his company charges $53 for a tree 17 inches in diameter, while the cost for removing that same tree can be $750-$1000. He says the process takes about 10 minutes per tree.

Whitmore confirmed the efficacy of emamectin benzoate, though he said it’s important for people to understand a few things before deciding to go that route. First off, if you see signs of the borer, like lack of leaves in upper areas and D-shaped holes in the trunk, you’re probably too late. If you want to protect a healthy tree, the oldest, grandest and most aesthetically appealing trees would be an intuitive first pick, but the circulatory systems in older trees mean the treatments are less effective than younger trees — it will probably still save the tree, but substantial areas might still get infected, and it might not look so grand when the borers get through with it. Once you begin treating a tree, pesticides will have to be reapplied every two to three years for as long as the borers are the area.

Do Ash Trees have a future?

Ash trees make up about ten percent of all threes in New York State’s deciduous forest, though in some areas, like the southern tier, that number is much higher.

Tell-tale signs of EAB infestation. Unfortunately, by the time a tree looks like this, it's too late.

Whitmore points out that when the emerald ash borer first turned up in North America eight years ago, “the total scientific literature amounted to about two paragraphs.” Since then, much has been learned about the species — it’s lifecycle, how it moves. “We have fantastic tools and really brilliant people working on the problem of resistance and in establishing bio-control, but they’re both very long-term,” he said. “It’s very difficult and will take a long time to really get going.”


Recently, a Cornell project undertook the first large scale release of a kind of Asian tree wasp, a natural predator of the borer, and Whitmore is hopeful that will show results, but they’re no silver bullet. “Will they be able to stop a massively expanding population of emerald ash borer? No. The release of natural enemies is a long-term thing that will be most effective when the population of EAB is kept at lower numbers through resistance or other means.”

Donohue said the situation isn’t necessarily as bad as Dutch elm disease because we know more about how the borers destroy trees than we did about that disease’s pathology, and an effective treatment is available.

More than anything else, both men stressed the need for people and municipalities to get out the message about firewood transportation and ash tree identification, because the slower the borer moves, the more time scientists have to find an antidote.

Not sure if you have ash trees on your property? Check out this ash tree identification site.


This article originally appeared in the August 19, 2010 issue of the Saugerties Times.