Stowaway U.S. Corn Rootworm Eats Its Way Across Europe

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"O'Hare is a very busy airport; there's a lot of corn production in the area; the beetles are there. One single pregnant female is enough, and in this case she succeeded," he said.

Mature beetles gorge on corn silk and leaves. The females lay their eggs—500 to 800 at a time—on the ground before dying with the autumn frost. The eggs hatch in the spring and the wormlike larvae devour the roots of the new corn.

"One or two larvae per plant will not cause economic damage. Eight, ten or twelve per plant is the level where you have yield loss. It usually takes six or seven years for the population to build up," said Kiss.

Ground Zero: Belgrade Airport

Ground zero in Europe's rootworm epidemic is Mirko Knezevic's corn patch, which abuts the Belgrade airport and is less the 500 yards (500 meters) from a hangar where aircraft are maintained and cleaned.

Knezevic, a retired bricklayer who farms a few acres to supplement his pension, first noticed the problem in 1992 when his young corn stalks started falling down because their root systems had been eaten away by larvae.

Ivan Sivcev, an entomologist who heads the department of plant pests for the Yugoslav government, recognized the danger immediately, but at the time Yugoslavia was deep in the throes of its ethnic wars and eradicating little beetles was not the priority.

In 1993, Sivcev helped draw up a plan to fight the infestation and Yugoslavia's Ministry of Agriculture appealed to FAO, the UN agriculture agency, for help.

"There was no reply. The international community didn't want to help Serbs," said Sivcev.

One of the few who tried to help was Purdue's Edwards. International sanctions precluded direct economic assistance to Yugoslavia, but Edwards traveled Belgrade as a private citizen to see if there was anything he could do.

"I think we could have contained it back in '94. It would have cost between U.S. $6 million and $8 million, but nobody would help out because of the sanctions. It was like Yugoslavia wasn't even a country," he said.

The Yugoslav government's first impulse was to impose penalties on its own farmers, but when it became clear that that wouldn't work, it then tried to sweep the problem under the carpet.

"During the political tensions, we were not allowed to speak about this. The politicians decided that it's better if people don't know about these problems," said Sivcev.

Huge Appetite for Farmland

Unchecked by any natural barriers, carried by winds and rivers and normal human traffic, the rootworm has spread rapidly. It has now infested more than 70,000 square miles (180,000 square kilometers) of farmland in the heart of Europe.

Hardest hit is Yugoslavia where an estimated 10,000 square miles (25,000 square kilometers) have been severely damaged. Last year average crop yields were down 30 percent in a country that is heavily dependent on its agriculture.

Sivcev works out of a cluttered office on the outskirts of Belgrade. What should be the command center in Yugoslavia's war on the rootworm looks more like a high school laboratory of 1950s vintage. A lot of the equipment is old and broken and Sivcev says there is barely enough money to pay the electric bills.

On the wall above his desk is a clipping from a wartime Croatian newspaper: "Dangerous Bug from Serbia Destroying Croatian Corn," reads the headline. From his desk drawer he pulls more yellowing clips, these from Serbian newspapers blaming the blight on a U.S. plot.

To this day, Knezevic, the farmer who was the first to find the beetle in his corn, is convinced Serbia's "enemies" planted the pest.

Sivcev shakes his head and laughs. "It came here before the civil war, and it would have gotten here sooner or later anyway. Traffic around the world is so developed there is no way to stop it. With air travel, a fertile female can enter a plane in Chicago and within 24 hours she can be in Belgrade," he said.

"Education is the only weapon we have. We have to teach our farmers the right strategies," he said.

Crop Rotation a Remedy?

In the U.S. farmers have been able to suppress the spread of the rootworm by scrupulously rotating their crops—corn one year, soybeans the next. The rootworm would lay her eggs in the cornfield and next spring the larvae hatched amid soybean roots which they could not eat.

But crop rotation is not so easy in Yugoslavia and other poor ex-communist countries where farms are small and profit margins slim. Farmers here grow corn to feed their own livestock, usually a few cows and pigs.

"Their whole system of living depends on corn. This isn't industrial-scale farming," said Sivcev.

Local farmers who have tried soybeans found that they don't grow well here. Sugar beets are a possibility, but they require a large front-end investment. Sunflowers thrive, but they bring low prices because the government is the only buyer.

Despite the problems, about 30 percent of the cornfields in Yugoslavia are now under rotation, but recently there has been worrisome news from America: A mutant strain of the western corn rootworm has learned to lay its eggs in soybeans fields in anticipation of corn being planted the following year.

The rootworm has already demonstrated an uncanny ability to adapt to pesticides, but this is the first time the insect has been able to adapt to a farming practice.

This stroke of genetic genius was first noticed in soybean fields around Piper City, Illinois, in the 1980s. It has now spread to the farmland just beyond Chicago's suburbs.

The fear in Yugoslavia is not that another one of these beetles will hop a plane to Belgrade, but that the ones in that country already share the same genetic make-up as their cousins in Illinois. The early indication is that they do.

Edwards, Kiss and others in the scientific community are leaning toward that conclusion, but say they need at least another season to observe the rootworms reproductive cycle.

Copyright 2001 Chicago Tribune

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