When John Binegar strolls under the shade of a Southeast Michigan forest, he doesn't much like what surrounds him: dead and dying ash trees, many of which stood tall for decades. The trees have provided a large slice of revenue for Binegar's saw mill, Hardwoods of Michigan. The hard, strong ash wood is coveted by the makers of furniture and baseball bats.
But the trees are no match for the emerald ash borer, an invasive insect first spotted near Detroit Metro Airport in 2002. Most likely, the bugs had arrived years earlier in wood packing material shipped from Asia. The borer has killed tens of millions of trees in Michigan and across the Midwest and Northeast, and it threatens billions across North America in the coming decades. The extinction of the ash tree on this continent could be the end result.
Some trees that Binegar finds may show just initial signs of an infestation — D-shaped holes in splitting bark and a dying upper canopy of leaves. Others stand completely stripped of bark and with few limbs. The limbs weaken and crash to the ground after the borer larva chomps a winding path through the wood, cutting off water and nutrients.
"It's been devastating, really," Binegar says. "It's basically shut down exporting logs out of this area." Each year, he says, the borer seems to have killed another mile-long stretch of ash trees.
Not only are there fewer trees available for harvest, but there are restrictions placed on the transportation of ash wood. State, federal and international governments fear the spreading infestation, and that has complicated the packaging and transporting of the wood.
The emerald ash borer hasn't just taxed business; it has strained the budgets of state and local governments that have to remove the trees and re-plant the forest. The borer has spread to 15 states in the past decade.
And the bug is far from the only one that has caused environmental officials to worry. The Asian long-horned beetle, the leaf-eating gypsy moth and the Asian stink bug are just a few of more than 60 non-native insect pests that have ravaged ecosystems and agriculture at taxpayers' expense, resulting in not only removal costs but also higher food and lumber prices.
The federal government spends $216 million each year on the fight against wood-boring pests, but most of that money goes to research, not to the protection or removal of actual trees. So state and local governments must bear the bulk of the cost of fighting the invasive bugs.
A recently published study in the journal PLoS ONE estimated that local governments spend about $1.7 billion each year as a result of invasive insects, with an additional $1.5 billion in lost property values. A 2010 study in the journal Ecological Economics concluded that the emerald ash borer alone will cost communities more than $10.7 billion in the next 10 years.
Bug assaults are not just a rural phenomenon. In Midland, a city of 40,000 in the center of Michigan's Lower Peninsula, about 20 percent of the ash trees are under insect attack. Fearing the safety hazards the fallen trees will present, city officials are hoping to spend $1.5 million over the next three years to save or remove some 28,000 trees. That funding would usually come from the city's forestry operations budget, but it was already near exhaustion last March.South of the Michigan border, Lucas County, Ohio — where Toledo is the county seat — is facing a massive ash die-off along its streets and in its parks. Ten percent of area trees are ash — largely because that was the species, thought to be highly resilient, that were chosen to replace its stock of elms eradicated by Dutch Elm Disease. Now, parks officials are planting a new variety of elm tree to replace the infested ash. "It hit us like a bomb," Scott Carpenter, spokesperson for Metro Parks of the Toledo Area, says of the borer's invasion. "We're kind of like ground zero."
Metro Parks used $1.2 million in federal stimulus dollars in 2010 and 2011 to cut down hazardous trees. Carpenter says the federal money has been helpful, but the public agency has had to halt all other natural restoration projects to concentrate on the ash problem.
Calling on wasps
Most experts say the borer cannot be completely stopped — just slowed. In Minnesota, which has the most ash in the country — more than 1 billion trees — officials expect to lose almost all within the next two decades. And researchers don't hold much hope for the other 6 billion ash trees across North America. They are talking about extinction in terms of when, not if.
With that in mind, most efforts to combat the emerald ash borer are meant simply to slow its rampage and spread out its costs. That may include spraying trees with pesticides, cross-breeding ash trees to make them more resilient, and thinning clusters of healthy ash trees to further stall the borer's advances.
In some cities, most recently St. Paul, officials have begun unleashing swarms of stingless wasps, one of the borer's few natural predators, to targeted areas. This method was green-lighted by federal agencies after extensive study found the wasps to have little negative impact on ecosystems.
But as federal, state and local governments continue to battle the existing invaders, researchers are warning that other pests may be on the way. Juliann Aukema, the lead author of the PLoS ONE paper and a researcher at the University of California at Santa Barbara, estimated in her study that there was a 32 percent chance of another borer species entering the U.S. over the next 10 years. That means that the most important front against the borer and other pests could be waged by customs officials.
Tightening the border
There are two main ways in which foreign pests enter the U.S. — in wood packaging or on plants shipped internationally. Environmental groups are working with the federal government in hopes of developing stricter standards for customs officials. Some of those policies, says Bill Toomey, director of forest health protection at The Nature Conservancy, have not been updated since the early twentieth century.
But the ability of even some modern options to keep pests out remains unclear.
The U.S., for instance, is one of 43 countries that have agreed to international standards of treating wood to rid it of pests before shipping. But pests are still getting in, prompting researchers to ponder whether the method is ineffective or some countries simply aren't following it.
Though the issue of invasive pests is unlikely to become a popular topic of discussion on Capitol Hill, two Democratic senators are trying to make the case to their colleagues that it should be.
Dianne Feinstein of California and Hawaii's Daniel Akaka have sponsored a bill, called the Safeguarding American Agriculture Act , that would create an Office of Agriculture Inspection within the Department of Homeland Security. The purpose would be to make scouring items for insect invaders a greater priority at the border.
That effort faded after the September 11 terrorist attacks, Akaka says, when federal customs, immigration, and agriculture inspection officers were merged under the new U.S. Department of Homeland Security. The numbers of invasive species entering the U.S. skyrocketed soon after the creation of the Homeland Security Department.
This week, an analysis of customs inspection records by the Associated Press showed that Akaka's concerns were well-founded. It disclosed that Homeland Security officers, many of whom were not properly trained to inspect threats to wildlife and agriculture, largely ignored such threats while maintaining their focus on detecting terrorism.
It's uncertain whether the goal of protecting native trees will resonate in a Congress looking to cut programs. But Aukema says pests should be a concern — especially for those hoping to save money in the long term. "You might not care about a tree, but you would care about its costs," she says.
As for John Binegar, he's holding out hope that he'll have at least some ash to process at his saw mill in the future. In his walks through the forests, he occasionally sees among the ash carcasses a few trees that seem to have been spared by the emerald ash borer.
Whether those trees will still stand tall next year is another question.