NEW YORK - Fulfilling the long-held fears of New York city officials and arborphiles, the Asian longhorned beetle, a voracious insect that has threatened vast swaths of trees in New York, Chicago and Europe, has for the first time surfaced among the prized maples of Central Park.
Two infected trees, one Norway maple and one sugar maple, were discovered within a nature sanctuary at the southern end of the park at the end of January, officials said.
"This is a serious thing for parks - you could potentially lose your parks over this," Mayor Michael R. Bloomberg said. "The only thing that you can really do when you find an infested tree is cut it down, chop it up and burn it."
Insects now dormant
The infested trees have been cut down and will soon be headed for the wood chipper and the incinerator, said Jane Rudolph, a Parks and Recreation Department spokeswoman.
Because the insects are now dormant, Rudolph said, there is no danger of further infestation, and officials delayed the incineration because they wanted to perform a thorough inspection of the surrounding trees before carting the infected ones away.
The city has been battling the destructive pest since it was first detected in the United States in 1996 in Greenpoint, Brooklyn. Since then, more than 3,500 New York City trees, among about 7,000 nationwide, have been killed by the insects, according to federal officials. Christine Markham, program director for the national Asian longhorned beetle division of the U.S. Department of Agriculture, said the beetle could easily thrive throughout North America, and would be limited only by the availability of host trees.
According to Adrian Benepe, the city's parks commissioner, more than half of the city's 5.2 million trees belong to one of the 25 or so species of hardwoods that are vulnerable to the beetle. In the northern areas of the country, he said, 1.2 billion trees are potential targets.
'No natural enemies'
"The beetle knows no bounds and has no natural enemies, and it now threatens some of the most magnificent living green treasures in New York City," Benepe said, mentioning the collection of American elms lining the park's Literary Walk, considered one of the country's finest.
"Imagine what happens if this makes it up to the maple sugar plantations in upstate New York and Vermont."
Rick Lepkowski, a spokesman for the Central Park Conservancy, said the city had been on particularly high alert for the beetle in Central Park since it first surfaced on the Upper East Side in the summer of 1999. He, too, worried about the potential loss of the park's stately elms, especially the ones along the Mall.
"My favorite time there is in winter, when you get that heavy, wet snow that sticks to the branches," he said, "and when you walk under them it's almost like a cathedral."
According to experts, the insects dig into the bark of hardwood trees, like maple, birch, horse chestnut, poplar, willow, elm and ash, to lay their eggs, which then hatch and burrow into the limbs, destroying tissue and cutting off nutrients.
At this stage, officials said, the clearest signs of infestation are the small piles of frass, or shavings of wood and beetle waste, that the larvae push out as they tunnel through a tree.
The adult beetles emerge around July, leaving round, quarter-inch holes in the trees. The eggs have thus far proven to be impervious to pesticides, so infected trees must be cut down, shredded and burned to prevent the insects from moving on to other trees.
The distinctive black-and-white beetle, which Markham described as "a showy insect," is about an inch or so long with antennae that can grow to more than double the beetle's length. As Joseph P. Gittleman, a program director for the Department of Agriculture's Animal and Plant Health Inspection Service, put it, "As far as beetles go, it's a pretty good-looking beetle."
Officials said that while the Central Park infestation, at least a year old, was limited to the two trees, they expected to find more as they continue scouring the park and the rest of the city.
In the wake of the discovery, officials plan to inspect all of the approximately 13,000 trees in the park that are vulnerable to attack, and will inject trees within at least an eighth of a mile of the infested maples with an insecticide to ward off potential infestation. (Although their eggs are impervious to insecticides, the adult beetles are not.)
5,000 trees examined
Douglas Blonsky, a Central Park administrator, said inspectors had already examined about 5,000 trees in detail.
Bill Hawks, an undersecretary of agriculture, said the federal government had spent about $21 million on its Asian longhorned beetle efforts in the city in the previous fiscal year, and expected to spend more than $30 million in the current one.
With the additional money, federal officials said, they have been able to employ better techniques, like putting inspectors in bucket trucks and hiring tree climbers, which is how city officials were able to discover the Central Park infestation. Before, inspectors would use binoculars from the ground, making it harder to detect evidence of the insect in the upper reaches of the trees.
Hawks, who said the secretary of agriculture had declared the infestation by the Asian longhorned beetle an emergency, added that it was crucial for homeowners to give his inspectors access to their trees for examination.
Standing inside the park near Fifth Avenue and 98th Street recently, Hawks said, "I look up on some of these rooftop gardens, and I see specimens up there that it's imperative that we get in and inspect those as well."
Hawks declined to specify how his agency would gain access to the private gardens, and later acknowledged.