This place is a warren of dim, concrete-floored rooms. The air is warm and humid, smelling of mothballs, soil and damp paper. Behind every closed door are scores of teeming cages. It's quiet here, yet somehow you feel like the space should be vibrating with sound — the sound of millions of insects.

This in an insect-rearing laboratory, where ravaging corn pests are coddled and coaxed to hatch, grow and multiply.

French Agricultural Research is one of a handful of independent insect-rearing facilities in the U.S. The lab in Lamberton, MN, raises 300 million corn pests a year for scientists around the world. Presiding over all these creepy-crawlys is a tall, genial entomologist with a thick shock of white hair and a pair of red-framed cheaters perched on his forehead. His colleagues call him “the Bug Man.”

Lee French has been raising corn pests in the heart of Minnesota farm country for nearly three decades. Along the way, he has mastered a demanding craft and supplied insects for groundbreaking research. And from his unusual vantage point — his own private “bughouse” — he warns farmers about the unrelenting threat of insect resistance.

THE CORN HYBRIDS and pesticides you use on your farm were very likely tested on insects raised by French Agricultural Research. Lee French and his wife Joann, a biologist, supply insects to all the major seed and crop protection companies, as well as universities and research groups worldwide. “We've sold insects in 48 states and many foreign countries,” Lee says.

The Frenches' lab and other insect-rearing facilities “make a very important contribution to research,” says Wade French (no relation to Lee), an entomologist at the USDA North Central Agricultural Research Laboratory in Brookings, SD. He's worked with the Frenches since 1999. “Lee has a well-respected reputation.”

Lee French studied insect-rearing techniques under the renowned University of Minnesota entomologist H. C. Chiang, then worked in ag-pest research for Union Carbide and Dow Chemical Company. In the late 1970s, he started running contract research trials on his family farm in southwestern Minnesota.

A couple of years later, the USDA Agricultural Research Service in Brookings asked him to start raising corn rootworms for the lab. “I asked if I could make any money at it.?”

Good question. Rearing insects is a lot trickier than you'd think. “There's an art to it,” Wade French says. “Many have tried and failed, especially with corn rootworm and European corn borer.”

The Frenches decided to give it a try. They put up a small building next to their farmhouse and began nurturing western corn rootworms. They laugh about their banker's skeptical reaction when they sought financing to grow noxious crop pests. But demand was brisk, and within a few years they were selling 175 million corn rootworm eggs a year.

As requests came in for other insects, they added new colonies. Today, the Frenches produce 10 species or sub-species in climate-controlled units. Their “livestock” includes diapausing and non-diapausing western corn rootworms, southern corn rootworms and northern corn rootworms. They also rear European corn borers, black cutworms, armyworms, corn earworms and tobacco budworms.

The Frenches have begun rearing a new insect, the Colorado potato beetle. “The government agency that was rearing it quit,” Lee says. “We're probably the only independent lab that rears Coleoptera, sheath-winged insects such as corn rootworm beetles, which must be fed a natural diet.

Most insects are shipped in the egg stage, “but we provide whatever the customer wants,” says lab technician Rozalyn Jeckell, who has worked with the Frenches for 22 years. “A researcher can say, ‘We want one million eggs laid on August 4,’ and we can do that.” The insects travel in insulated boxes, with hot water bottles in the winter and ice packs in the summer.

It takes two or three years to learn how to raise an insect colony, says Lee, author of an entomology textbook chapter on rearing methods. “There's a lot of trial and error.”

Insects are sensitive to environmental conditions such as light, temperature, humidity, soil traits and diet, as well as fungi, parasites and bacteria — all forces that curb them in your cornfields. It's common for insect-rearing labs to lose entire colonies, Lee says, although French Ag Research rarely has. One reason: He and Joann live right next door to the bughouse.

“So we see them every day, seven days a week.” He shakes his head and grins. “I milked cows growing up, and I said I'd never want to do that. So look what I ended up doing instead. We have to be here every day.” Still, he adds, “I love what I do.”

ANOTHER REARING challenge is the speed at which insects change in response to the controlled lab environment. European corn borers adapt to an artificial diet so fast that within a year — about 20 generations — “you can put them on corn plants and they will starve,” Lee says.

Other changes are more subtle. Colonies “adapt to the warm climate in the lab — no wind, constant humidity,” Wade French says. “But nature is not so nice.” The lab environment “selects for genotypes that do best under those conditions, so you lose genetic diversity.” That means the lab insects used to develop and test pest-control methods “may not be representative of the natural population,” clouding the data.

Through the American Entomological Society, “Lee took a leading role in raising awareness of this problem,” Wade French says.

To maintain genetic diversity, the Frenches replace their insect colonies every one to three years, depending on how fast the species adapts. They start a new colony of European corn borers every year, for example. Joann French, a former wildlife researcher, spends most of every summer traveling around the Midwest collecting wild corn pests. “We make sure that what we raise is what is actually in the field,” Lee says.

The same relentless forces of natural selection that are so visible in the Frenches' lab are also at work in your fields. “Insects will change their biology in response to whatever we do,” says Lee, who also teaches college environmental science.

Corn rootworms (CRW) are a classic example. As farmers know, northern and some western CRW now wait two years to hatch, so corn will be available in a corn-soybean rotation, while in Illinois and Indiana, adult western CRW beetles often lay their eggs in soybeans. Likewise, European corn borers, responding to selection pressure from widespread use of transgenic corn, are now infesting potatoes, peppers and mums, Lee says.

Lee predicts that CRW will eventually overcome the Bt-CRW gene, weakening its usefulness. And it could happen sooner rather than later if growers become lax about planting the required insect refuges. “I know it doesn't always happen,” he says. “I think people get so comfortable, they say, why should I do it? I'll just plant all GMOs.”

Despite farmers' best efforts to defeat yield-robbing pests, Lee says, the bugs always win in the end. “You could have a nuclear bomb, and you'd still have insects.”