Bugs Without Borders

For the planet's most voracious insects, Minnesota is just one more pit stop

If you have a bug story to tell Art Mason, he'd appreciate it if you'd bring the carcass. Recently, he says, his neighbor told him about seeing a tarantula on her rear-view mirror a day after a grocery run: "It probably had gotten in on bananas in her groceries. She called me, frantic, and I asked her, 'Where's the specimen?' She said, 'There's nothing left for you on this one. It's smashed on the road somewhere.'"

Mason is Minnesota's state entomologist--the man in charge of monitoring flying and crawling threats to the state. Bespectacled and professorial, he clearly relishes his job--a position for which, he notes, he began training at an early age: During his childhood in Maine, his family put him to work picking up plant-munching Japanese beetles in the garden. "You know how little children can watch ants for a long time?" he grins. "I never outgrew that. When I go grocery shopping, I'm looking for insects."

But Mason's brow furrows as he rattles off the list of creatures that have been showing up in Minnesota in recent years. The Japanese beetle he used to chase out East has made its way here in nursery stock. Shoppers not infrequently discover black-widow spiders on grapes in local produce departments; shipments of fresh flowers covered with foreign thrips are routinely turned back at the airport. "In all of the 37 years that I've been working in entomology, I've never been more concerned with all the species threatening this country," Mason says.

Minnesota state epidemiologist Art Mason tracks the new global migrants
Michael Dvorak
Minnesota state epidemiologist Art Mason tracks the new global migrants

Earlier this year those concerns were echoed in Washington, when President Clinton signed an executive order appointing an inter-agency council to create an "invasive species management plan." The executive order noted that "the total economic impact of invasive species on the U.S. economy is estimated to be about $123 billion annually." Clinton's budget for fiscal year 2000 proposes an increase of almost $30 million in the budgets of various agencies to combat invasive species.

Minnesota legislators have also jumped onto the bug-fighting bandwagon: This spring lawmakers appropriated $276,000 in new funds for Mason's office, a 40 percent increase over the current budget of $700,000. But even that, says Mason, is only a drop in the bucket when you're dealing with something like the Asian long-horned beetle.

So far, no one in Minnesota has seen the two-inch long, black-and-white spotted beetle with the whiplike antennae and the voracious appetite for wood. But the insect has caused the destruction of more than 2,000 trees in New York City, where it is thought to have arrived in the wood of pallets from China in late 1996. A similar infestation now plagues Chicago, where 500 infested trees have been removed since the beetle showed up last July. The Asian long-horn doesn't fly far, but it will hitch rides when it can; at one point, Chicago bug hunters suspected that it might be riding the El train from one location to another.

What bothers entomologists about this particular beetle, says Mason, is that they seem to be powerless against it. "We have no chemicals to control it, no biological control, no pheromone that attracts it. We don't even have methods for looking for it." The only way to stanch invasion seems to be to establish strict quarantine areas, cut down all the trees in them, and burn the wood. Asian long-horns have been found in shipping yards and warehouses across the nation; in the Twin Cities, staffers from the state and federal Departments of Agriculture have combed warehouses where pallets made of Chinese wood might be stacked. Thus far they haven't found anything. But it's only a matter of time, says Mason--and, perhaps, of coincidence: In Chicago the beetle was first discovered by a man who'd bought a load of firewood and found the creature in the bed of his truck.

Recently, while vacationing in northern Minnesota, Mason wandered into a sporting-goods store for a quick browse and noticed something that made his heart sink: "There was a stack of the crating material that barbells had come in. There were huge holes in it, probably made by the Asian long-horned beetle, probably back in China, but we can never know that for sure." Mason quizzed the shop owner and found out that the crates were the last from a large shipment, and that the rest had already gone to a landfill. "We have our work cut out for us," he concludes wryly.

The arrival of the Asian long-horn is a reminder, Mason and other bug-fighters say, that national boundaries mean nothing to insects. The USDA has more than 1,300 inspectors stationed at 90 ports and border crossings; in some of those places, including the Minneapolis-St. Paul airport, they are accompanied by dogs trained to sniff out vegetables, plants, and fruit. But there's no way those inspectors could disassemble every crate or rummage through every suitcase, says Scott Tincher, senior officer for the Animal Plant Health Inspection Service (APHIS) office at the Minneapolis-St. Paul airport.

In Minnesota, says Tincher, "most of the insects we find are on passengers. A lot of people want to bring back fruit from where they've been traveling. They don't realize that they can bring back a harmful insect along with their gift. We can look at that perfectly healthy mango, and if it came from India, the Philippines, or Nigeria, we know that it probably has a mango weevil lurking inside."

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