In the beady eyes of two invasive insects, the Philadelphia region would be a bacchanal - an orgy of fine food and wild sex amongst the maples, sycamores, birches and ashes that shade the city and suburbs.
Were the Asian longhorned beetle and the emerald ash borer to converge here, potentially half of the urban forest - well more than a million trees - could be fatally infected.
Such is the worst-case scenario. And it is inching closer on six spindly legs.
Bearing down on Pennsylvania from the west is the ash borer, a glitter-green bug about a half-inch long that lays its eggs on the bark of ashes. The larvae burrow inside to feast, creating serpentine channels of sawdust that cut the tree's nutrient flow.
Thought to have slipped into the United States from China on wooden shipping pallets in the early 1990s and spread undetected for several years, the borer has surfaced in Ohio and Indiana and as far north as Ontario.
It has been most ruinous in its suspected port of entry. The borer has laid waste to 15 million of Michigan's 700 million ashes, turning neighborhoods around Detroit into open range.
Meanwhile, in North Jersey, chain saws have been buzzing, stump grinders growling. Since spring, 8,000 trees have been felled in an effort to stop the Asian longhorned beetle, which also has shown up in Chicago and New York City.
About one inch long, with white spots on a black body, it is distinctive from the borer in more than looks. Its appetite is dangerously diverse: maples, sycamores, poplars, birches, willows, horse chestnuts - a regular hardwood smorgasbord.
Neither insect flies far, perhaps a half-mile from a host tree. Then again, it doesn't have to. The borer is tiny enough to be sucked into the updrafts of a storm front, barreling east to rain down on the 340 million ashes in Pennsylvania and New Jersey forests.
Humans often give them a lift, as well. The transport of infected firewood has been blamed for many ash borer outbreaks; last year, Michigan border inspectors stopped a truckload of wood harboring the pests and bound for the Poconos. One longhorn infestation in North Jersey was believed to have started with a beetle that hitched a ride on a commuter's car and hopped into a tree under which he parked.
Forestry officials and arborists in Southeastern Pennsylvania and South Jersey are watching - and preparing.
The region lost its chestnuts in the early 1900s to chestnut blight, also an Asian import. By the 1970s, the elm, a signature city tree of elegantly arching branches, was decimated by Dutch elm disease. What replaced them in the urban canopy now stands in harm's way.
"I think it's possible for the emerald ash borer to completely wipe out ash in the East," said Jim Stimmel, an entomologist with the Pennsylvania Department of Agriculture.
The longhorn also has "horrifying potential," said Paul Meyer, director of the Morris Arboretum in Philadelphia.
One of its preferred hosts is the sycamore, widely planted in the region. "Boy, if the beetle came in and devastated the sycamores, that would have a profound impact," Meyer said.
From time to time, the U.S. Department of Agriculture's Philadelphia office has gotten calls, typically from residents, about suspected longhorn sightings. The agency recently surveyed a mile-wide swath of trees around a Bucks County, Pa., landfill, on a tip that it held wooden packing material possibly infected with the pest.
All of the reports have been false alarms. But no one expects that luck to hold forever.
Donald Eggen, forest health manager for Pennsylvania's Bureau of Forestry, is one of them. "Right now," he said, "we're in search mode."
The infestations in the Midwest and Northeast are largely in industrialized areas, where the bugs have debarked from import warehouses.
Experts aren't sure how the bugs would behave if loosed in the nation's vast forests - 17 million acres just in Pennsylvania, 2.1 million in New Jersey - but they don't rule out a binge.
So, this summer, the USDA dispatched five inspectors in Pennsylvania to examine sites where ashes are common: campgrounds and cemeteries. In state parks, signs warn against bringing in firewood.
A mating pair of borers, producing 75 eggs a year, could spark an infestation that would play havoc with not only the ecology and tourism. Even baseball would take a hit.
All of the ash for bats, including the Louisville Slugger, comes from a section of forest straddling northwestern Pennsylvania and New York - about 200 miles from Detroit.
From the air, Michigan still looks green.
But at ground level in the Detroit suburbs, the skeletons are everywhere. One leafless ash tree, then another, then an entire block denuded.
In the summer of 2002, Michigan State University's Deb McCullough joined other entomologists around an ash where someone earlier had seen an odd insect. Pulling back the bark, they found a mosaic of pathways.
That night, McCullough told her husband: "This is going to be big. I've never seen anything like that."
Within weeks, the state quarantined six counties. No ashes, dead or alive, could leave.
And still, the borer spread.
Today, 20 counties - an area larger than New Jersey - are under quarantine. State fines for taking ash wood outside those areas have been raised from $100 to as high as $250,000. At least five people have been prosecuted.
And still, the borer spreads.
Because the adults hang out in the upper canopy and the D-shaped holes from which they emerge after their larval stage are tiny, early detection is almost impossible. The rings of the tree where McCullough found the first borers in 2002 indicated that it had been under attack since 1992.
Although science is on the case, there is no fully effective insecticide against the borer.
Fighting leaf-eaters such as gypsy moths is simpler. "Hire a bunch of airplanes, and load them up with insecticide," said Noel Schneeberger, a U.S. Forest Service entomologist.
With wood borers, there's "not much we can do except take out their homes."
Michigan has, in fact, devised a plan to cut all ashes, even healthy ones, within a half-mile of an infestation, but it lacks the money to do it. Such moats, however, have not deterred the borer elsewhere: Canada spent $10 million in a vain attempt on an isthmus east of Windsor.
In the Detroit area, the borer already has chewed deep into municipal budgets and residents' pockets.
"There isn't an individual who isn't impacted," said Sharon Lucik, a USDA spokeswoman in Michigan. "I may not have (lost) a tree in my yard, but maybe my taxes are going up."
Stricken ashes have to come down, one way or another. Although an elm is strong even in death, an ash quickly disintegrates, posing a safety hazard.
In Westland, a city of 86,000 west of Detroit, clearing thousands of dead and dying trees along streets and in parks cost $1 million in two years. Ann Arbor is about to put a $4 million bond issue for ash removal on the fall ballot, an average $50 tab per homeowner.
When trees on private property die, residents are on their own, facing a bill of $1,000 or more to remove a mature specimen. Local governments are trying to cut group deals, but $300 a tree is the best they've done.
Even healthy ashes are a liability. Growers are burning the stands they've raised, a loss estimated at $8.6 million.
(One who didn't do so shipped infested trees to a Maryland dealer, who sent some to Virginia. The borers were found before they spread.)
To stop the movement of firewood, the state has set up vehicle checkpoints at borders, bridges, and highway rest stops. Entering Michigan from Canada, travelers are asked whether they are carrying firearms, liquor, cigarettes - or firewood.
Will this stop the bug? Maybe, the most optimistic say.
Others are making contingency plans.
The USDA in Michigan intends to collect ash seed and send it to the National Center for Genetic Resources in Fort Collins, Colo. There, it is to be frozen and stored in liquid-nitrogen vaults for planting in the future.
High above New York City's Central Park, the branches of a giant elm shook. Look! Spider-Man!
Or so it appeared to wide-eyed children riveted by the sight of Bob Bente in a treetop.
From March through June, he and fellow "smokejumpers" - expert climbers who fight forest fires on the other side of the country - scoured Central Park at the USDA's behest. They were looking for something they hoped not to find: minute indentations in bark indicating that Asian longhorned beetles laid eggs there.
Among the park's 25,000 trees are 7,000 potential hosts, including the last great stand of American elms in the nation.
By the time the smokejumpers finished, they had checked 3,800 trees. Two along Fifth Avenue were infested; they were chopped, chipped and burned.
USDA officials decided to spare the park the devastation of mass preventive cuttings.
But not in North Jersey. There, the tactic is to hit `em hard.
In quarantined portions of Middlesex and Union Counties - 16 square miles of mostly modest homes and mature hardwoods - the discovery of a single exit hole brings in the chain saws. All potential host trees within a quarter-mile are cut down; insecticide is applied for a quarter-mile farther.
Nearly 8,000 trees were dropped just last spring.
Barry Emens, director of the USDA's longhorned beetle program in New Jersey, knew that not all would turn out to be infected. But 517 did. One maple had 800 exit holes.
In other words, 800 adults had emerged and flown off, to lay eggs elsewhere.
As important as what the insects eat is what they don't eat.
In North Jersey, Emens comforts bereaved homeowners with a list of species that can replace their departed trees. Dogwood, crab apple, hawthorn, redbud, magnolia, yellowwood, ginkgo, honey locust, linden, beech - 42 in all that, for whatever reason, the bugs eschew.
He also has one word for them: diversity.
Foresters call it the "look-around rule." Before planting a tree, stand in the spot and look around. If you see another one like it, plant something else.
Emens has spent 20 years on the Riverton Shade Tree Commission, preparing his own town for the worst. Its streets, he proudly notes, are lined with 150 species. Should the longhorn or the borer come calling, not all of them would be on the menu.
"The diversity of the trees is better for the community," he said. "So when the next thing comes along - which there will be - we'll be prepared."Charlotte Observer
