Cities Under Seige

American Forests, Summer, 2000 by Mary M. Woodsen

As scientists work to eliminate Asian longhorned beetle in New York and Chicago, trees are coming down--and the rest of the country is getting worried.

We call it the Asian longhorned beetle. The Chinese call it the starry sky beetle. Forest entomologists call this inch-and-a-half-long insect with starburst sports on burnished black wings potentially the worst ecological disaster North American forests have ever seen. Because the pest enters the country through heavily populated port cities, urban and suburban forests are at risk, and New York and Chicago are already under assault.

It has been almost four years since the Asian longhorned beetle was first found in Brooklyn, New York City, and some suburbs; those areas have now lost 4,500 trees. In Chicago and outlying areas more than 1.320 trees have come down. And the beetles have been intercepted in 26 other cities. If they make it beyond those bounds, the result could decimate forests across the continent.

That's because unlike the most recent national pest threat--the gypsy month--Asian longhorneds don't just weaken trees, they kill them. And the only way to control the pests is to take down infested trees.

As AMERICAN FORESTS has shown in its regional ecosystem analyses, when cities lose a major portion of their tree canopy, they lose much more than cooling shade and aesthetic delight. Cities would be hard-pressed to provide an equivalent value in stormwater management, air quality, water quality, energy conservation, and wildlife habitat. In stormwater management alone, the nation's urban forests provide estimated services with a value of more than $400 billion each year.

AMERICAN FORESTS is raising money to provide tree-planting grants to organizations in the Chicago area. Individuals and corporations, including specialty retailer Eddie Bauer, are providing donation. To contribute, see "An Asian Longhorned Primer" on page 8.

Those new trees will be sorely needed as neighborhoods there and in New York struggle to overcome the damage the beetle has inflicted.

"When I first laid eyes on this beetle, I has the feeling it could be bad news," says Rick Hoebeke, the Cornell University entomologist who first identified the strange insect. "I checked it against our collection, and... made plane reservations right away. Two days later I was at ground zero, in Greenpoint. Brooklyn. I was blown away. It was far worse than I had imagined."

The trunks on the sugar maples Hoebeke examined looked as if they had been used for target practice. A thick blanket of fine sawdust lay beneath each tree. The dime-sized holes were exit points for adult beetles that had probably spent a year or more tunneling through the tree as larvae.

Within two weeks teems headed by the USDA and the New York state Department at Agriculture and Markets were scouring Greenpoint; more damage wee found in Amityville. Before long patterns emerged, with maples and horsechestnuts hard hit and London planes and lindens unaffected.

While the surveys continued in Brooklyn and Amityville, researchers at the USDA'S Otis Plant Protection Center on Cape Cod got busy figuring out just how the beetles had arrived. They soon made a connection to China's huge and steadily increasing volume of exports to the united States--now valued at almost $80 billion dollars a gear.

When the Chinese began planting vast acres of poplar trees to satisfy a demand ins wooden packing crates (as well as fuel, and with breaks) its population of starry sky beetles skyrocketed.

"Between 1977 and 1987 the beetle's population increased 500 times," says Vic Mastro, Otis' director. "Then it exploded. By 1991 populations were a whopping 6,500 times--that's roughly 650,000 percent--greater than before.

"We found that the Chinese were scrambling to figure out how deal with this pest, too." Mastro says. "It took us a long time just to figure out how to raise the beetle in the lab so we could experiment with it. In fact, for our first tests we had to use plastic fishing worms--they were about the size of the beetle larvae."

Even as researchers were setting up collaborations with Chinese scientists, trees were coming down in Greenpoint and Amityville. "They had to take huge 60- to 70-year-old trees out through people's living rooms," says Annette Kupiec, cofounder of Neighborhood Roots, a Greenpoint community group that fought for appropriations for replanting. "It was almost unreal."

In July 1998, midway through the New York City region's efforts, the beetle was found in Ravenswood, a Chicago neighborhood. Smaller infestations turned up in the suburbs of Addison and Summit. Just last year the beetle was fond in the Cook Count Forest Preserve, in Kilbourne Park, and on the Loyola University campus.

In Ravenswood, crews cordoned off the affected areas early in 1999, well before the beetles emerged, and dropped infested trees right in the streets. These trees, many of them Norway maples more than two stories tall, had been planted after Dutch elm disease decimated so many city streets during the 1960s. Once gain some blocks were losing almost all of their canopy.