The mess sitting before the lab worker looked like a frozen dinner gone horribly wrong: all bug legs, beetle backs and curlicue antennae.
The lab worker was, in fact, looking at a sample of insects captured in a DeKalb County field, scouring it for one of the most damaging and genetically clever pests that ever came buzzing into Illinois: a beetle called the western corn rootworm.
One by one he picked out the notorious beetles until his pile reached 16. A year ago, there was only a 50-50 chance that a sample from DeKalb would have even one of the beetles.
New data released this month show that a mutated strain of western corn rootworm, one that has evolved in a jiffy to outsmart farmers, is spreading from central Illinois faster than scientists had anticipated. For the first time it is causing crop damage as far north as Kane, Kendall and DeKalb Counties, said Mike Gray, an entomologist at the University of Illinois Extension.
"This is the first year I have seen root damage that would suggest they have a problem that far north," Gray said after spending the summer in Illinois farm fields.
In the short term, the rapid spread of the mutated rootworm means that farmers will begin to apply tons of pesticides on soil that before needed none, exposing farmers and their hired hands to poisonous chemicals. By one estimate, it could add $100 million in pesticide costs to Illinois corn production in an era of low grain prices.
In the long term, it means farmers will likely watch seed prices soar as genetically engineered corn, armed at the cellular level with weapons to kill off pests, becomes perhaps the only weapon left in the agri-arsenal.
Even genetic engineering is likely to eventually fail, however, as the western corn rootworm will be pressured to develop a genetic resistance to the pesticides in transgenic plants, as well.
"I think there are many entomologists who say it is not a question of if, it is a question of when," Gray said.
The western corn rootworm is a case study in the critical gamesmanship between man and nature: Nearly every time humans figure out a clever way to conquer a pest or disease, nature comes up with an even more impressive countermove. Cockroaches feed on the poisons that once killed them; bacteria grow immune to antibiotics.
Despite the rootworm's stature-- it's smaller than a housefly--perhaps no beetle serves as a better example of how an insect's random mutations can exploit man's world.
"This is evolution right in front of our eyes, and it is happening very quickly," said Eli Levine, an entomologist with the Illinois Natural History Survey.
"This is essentially a man-made pest. I think it will adapt to pretty much anything."
The clues to why an entomologist would call an insect a "man-made pest" can be found along the evolutionary path the corn rootworm followed to bring it to the farmland just beyond Chicago's suburbs. The beetle has been an evolutionary machine, undergoing three substantial shifts in its genetic makeup to fit into a world altered by agriculture.
Somewhere amid the farm fields around Piper City, Ill., sometime in the 1980s, some of the small yellow-and-black beetles did something none of their ancestors had done before: They began laying their eggs in soybean fields.
Unremarkable as that might seem, it was an expression of Darwinian genius.
The corn rootworm had been entirely dependent on corn. She laid her eggs in the soil of a cornfield one year, and her wormlike young hatched the next summer amid a field of succulent corn roots, which they ate ravenously.
Farmers in central Illinois, however, had been religiously rotating their crops--corn in a field one year, soybeans in that field the next. Along with other benefits, the practice suppressed the population of the western corn rootworm.
When a rootworm laid her eggs in a cornfield where crops are rotated, her young hatched the next year amid soybean roots, which they could not eat. That rootworm would not reproduce, so would pass along no genes.
But then for some reason, some corn rootworms laid their eggs in soybean fields instead of cornfields: The next summer, after the crops had been rotated, the rootworm larvae emerged to find corn roots to eat and so could live and reproduce.
Those mother rootworms had passed on the weird tendency to lay eggs in soybean fields to their offspring.
In 1987, Levine discovered that Piper City had become an epicenter of a growing wave of the beetles that were laying their eggs in soybean fields, almost as if they knew that there would be corn growing there the next year when the eggs hatched.
"If you have an insect that does something a little strange, like leaving the cornfield to lay her eggs, that will be selected for in this case," Levine said. "All it takes is this strict selection pressure.
"Where it developed is no accident," Levine said. "This is an area where there is very strict crop rotation. Some farmers didn't even have equipment to put down soil insecticides."