The invaders are merciless. They are, apparently, unstoppable. They’re as close as Whitney Point and Tully. And they’re coming to Cortland.
The invaders are emerald ash borers, and when they’re done their pillaging, expect one in 10 trees in Cortland County to be dead and rotting.
That would be just about every ash tree.
“Over the past 30 years, I haven’t seen a pest where the outlook was so grim,” said Brett Chedzoy, a forestry specialist with Cornell Cooperative Extension. “It’s pretty much 100 percent of every ash an inch in diameter or larger.”
The emerald ash borer comes from east Asia, and was first discovered in Detroit in 2002. Since then, it has spread in an invasion route that largely follows the nation’s highways. They arrived in New York in 2009.
The borers, themselves no more than a half-inch long, leave behind D-shaped exit holes, snaky grooves in the wood as larva eat and grow, split bark and a tree canopy that dies from the top down. The trees die within three to four years of infestation.
They’re probably already here. Onondaga and Broome counties are among the 24 counties infested and quarantined. Parts of Chenango and Cayuga are quarantined, too, meaning ash wood, logs, firewood, nursery stock and wood chips cannot be taken out of the community.
That won’t stop them. “It’s basically a little green cockroach,” Chedzoy said. “They’re tough to kill and don’t have a lot of natural enemies.”
They’re also sticky little buggers. They’re not great fliers — their infestation areas will spread four, five miles a year — so forestry experts and biologists had thought they moved primarily through firewood from one area to the other, hence the quarantines.
“With the beginning of camping season in full swing, it is important to remind travelers to New York state to use only local firewood,” said DEC acting Commissioner Basil Seggos in announcing the sixth annual emerald ash borer awareness week last week. “The spread of these insects, and other forest pests, has been dramatically increased through human transport.”
But park under an infected ash tree and they’ll stick to a hood or rooftop for a long time, hitching a ride to the next forest canopy. With few predators — woodpeckers will eat the larva, though they damage the tree in the process — there’s not a lot to stop them from multiplying.
“It’s not like a few bugs attack a tree, it’s more like hundreds or thousands,” Chedzoy said.
Rick Carter, owner of Carter’s Tree Service in Cortlandville, said last week he hasn’t seen much sign of infested ash — blue spruce and pine are a large part of his business. But that doesn’t mean he won’t see them soon. And even if he doesn’t see them, he’ll soon start taking down ash trees ahead of the invasion wave.
The state Department of Environmental Conservation policy is dubbed “Slow Ash Mortality,” or SLAM. Essentially, it’s the arboreal equivalent of duck-and-cover: remove the infested trees, monitor the spread, work to find a chemical or biological solution.
Realistically, conservationists are beginning to save seed and sapling, particularly through the Mid-Atlantic Repository Seed Bank, Chedzoy said, with the hope that when the borer blows over, they’ll have enough genetic stock to re-plant.
Cornell Cooperative Extension plans to harvest the ash trees from its 4-H Camp Owahta, said extension Executive Director David Rutherford. “That hillside is covered in ash,” he said of the Solon camp. “Now’s the time to get them cut.”
That will mean less food for the borers, and can also bring a little income to the organization. Carter estimated a typical ash tree can yield a couple of cords of firewood, which nets him $120 or more a cord.
Lime Hollow Nature Center is doing something similar, Executive Director Glenn Reisweber said. “We’re tagging and felling ash trees,” he said, and planting new understory coverage to fill the gap.
Chemical solutions are available, Chedzoy said The city of Syracuse hopes to save 1,000 trees near Onondaga Lake with pesticide, which was drilled into the wood last year, and cut 1,000 more. But the inoculations cost $15 per inch of tree diameter, so it must be a pretty special tree to merit the cost. And even then, it’s not a permanent solution.
Experts in Ohio are releasing parasitic wasps as a biological solution, Chedzoy said, but do the math: thousands of wasps, hundreds of millions of ash trees in New York alone. Each tree potentially feeds thousands of emerald ash borers.
However, he pointed out, hope remains, in a post-apocalyptic sort-of way.
Survivors have been found in the Midwest, apparently resistant to the emerald ash borer. Perhaps a new strain can be developed from them.