TIFTON - Move over, drug-sniffing dogs.

Make way for the wasps.

With just a wisp of scent, these tiny Georgia insects can identify not only drugs, but crop pests, explosives, diseases and dead bodies.

They are far more versatile than drug dogs, which cost thousands of dollars to train and usually work with only one person. Tifton scientists say they will cost pennies per thousand to rear and can learn a scent in 30 seconds.

Joe Lewis, a research entomologist for the U.S. Department of Agriculture's research service, has been studying how the wasps can be used by farmers, police, anti-terrorism officials and doctors.

Glen Rains, an associate professor of biological engineering at the University of Georgia, recently developed a "wasp hound" to monitor the insects' responses.

"You can't put them on a string and let them kind of fly along beside you," Lewis joked.

The wasp hound consists of a 2-inch round Plexiglas cartridge in a container with a light and camera.

About five of the quarter-inch wasps wander around the cartridge until they smell the scent they were trained to recognize. They congregate where it enters. The device is hooked to a laptop, which graphs the intensity of the wasps' response.

Eventually, Rains hopes to analyze individual wasp movements until smells can be tracked to their source - maybe even using a robot the wasps steer with their movement.

The parasitic wasps have evolved a fine-tuned sense of smell to locate the caterpillars in which they lay their eggs, Rains said. ( The wasps sting only caterpillars, not people. )

Lewis and other researchers discovered in 1990 that a plant attacked by the caterpillar releases an odor that tells the wasp where to find the caterpillars. The wasps lay their eggs in the caterpillars, which die but serve as incubators and food for the wasp larvae.

"This helped us really understand this espionage game between the wasp and the caterpillar," Lewis said. "The plant sends out the secret messages: 'Hey, Good Guy! I'm under attack! Come and help me!' "

Eventually Lewis discovered that all plants use scent to send out specific messages to different insects, like calling up a particular friend for help. They know which "number" to call based on which disease or pest threatens them.

Without genetic alterations, the wasps can be trained to answer any of these calls after three 10-second exposures while feeding or egg-laying, Lewis said. When wasps smell it again, they display feeding or attack behavior.

The idea was originally developed to help farmers, although it has taken some almost science-fiction-style twists during the years. The U.S. Department of Defense asked Lewis' team to study whether the wasps could be used like drug dogs.

"We at first kind of put them off," he said. "Their vision was to release these in an airport and they'd kind of hover over the drugs."

Although that was a bit far-fetched, the wasps could be trained to recognize marijuana, perhaps with enough precision to identify where it was grown. Wasps can also learn bomb-related odors and nerve gas, Lewis said.

But the wasps will probably be used first in farming. Rains said he expects to start using the wasp hound next year to find root worms, called nematodes, that attack cotton underground.

"One use we envision is to put the ( wasp hound ) on a tractor and go across the field and monitor for new diseases or bioterrorism," Lewis said. It could also be used to zero in on which areas need to be treated with pesticide or fungicide, Gains said.

"It sounds wonderful if it would work," said Chuck Ellis, Dooly County Extension agent. "I'm not going to discount it, because anything that saves money or will allow farmers to produce a higher quality crop, we've got to consider."

The wasps can even pinpoint a cancer-causing toxin sometimes contaminating peanuts, Rains said. Peanuts tainted by the toxin can only be used for animal feed and bring two-thirds their potential price, Rains said.

"Sampling now is very imprecise," he said. "With this you could sample the air above the peanuts, and it would be more representative of the whole load of peanuts."

The wasps could be used to fight cancer even more directly. Dogs have already been trained to "smell" skin cancer on a patient, and wasps could do the same, Lewis said.

"We don't understand how this works because our best machinery can't even pick this up," he said.

The wasps have been trained to locate dead bodies by recognizing the smell of decomposition compounds, said Jeffery Tomberlin, assistant professor and extension specialist at Texas A&M University.

Police searching for a body could mark off a grid and take soil samples from each section. The wasps could be exposed to these one at a time in a lab, Tomberlin said.

Their reaction can direct police where to dig.

Soil samples could be collected and analyzed in a day, in a process less cumbersome than the current method of X-raying wide swaths of ground, he said.