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TIFTON, Ga. - Trained wasps could someday replace dogs for sniffing out drugs, bombs and bodies. No kidding.
Scientists say a species of non-stinging wasps can be trained in only five minutes and are just as sensitive to odors as man's best friend, which can require as much as six months of training at a cost of about $15,000 per dog.
With the use of a handheld device that contains the wasps but allows them to do their work, researchers have been able to use the insects to detect target odors such as a toxin that grows on corn and peanuts, and a chemical used in certain explosives.
"There's a tremendous need for a very flexible and mobile chemical detector," said University of Georgia agricultural engineer Joe Lewis, who has been studying wasps since the 1960s. "Our best devices that we have currently are very cumbersome, expensive and highly fragile."
The "Wasp Hound" research by Lewis and U.S. Department of Agriculture entomologist Glen Rains is part of a larger government project to determine if insects and even reptiles or crustaceans could be recruited for defense work. That project has already resulted in scientists refining the use of bees as land-mine detectors.
Through the years, Lewis and a USDA colleague, J.H. Tumlinson, discovered that a tiny, predatory wasp known as microplitis croceipes had relied on odors to locate nectar for food and hosts for its eggs - caterpillars that damage crops.
While they don't sting humans, the female wasps use their stingers to deposit eggs inside caterpillars, producing larvae that eventually kill the caterpillars.
The scientists also discovered that plants being attacked by the caterpillars give off SOS scents to attract the all-black wasps and that the quarter-inch-long insects could be trained to associate other odors with food and prey.
"They have to be good detectors because their whole survival depends on it," Lewis said.
Rains said the wasps can be trained to detect a specific odor very quickly. The researchers expose hungry wasps to the target odor, then let them feed on sugar water for 10 seconds and then give them a one-minute break. After three repetitions of sniffing and feeding, the wasps associate the odor with feeding.
Since the scientists couldn't put leashes on their wasps, they needed a way to contain them while monitoring their reactions to odors.
Enter the Wasp Hound - a 10-inch-long cylinder made of PVC pipe with a hole in one end and a small fan on the other. Inside is a Web camera that connects to a laptop computer for monitoring five wasps housed in a transparent, ventilated capsule.
When the wasps detect a target odor, they converge around the vent, creating a mass of dark pixels on the computer screen.
"What we have ... is a technology-free organism that you can quickly program and use in a highly mobile way," Lewis said.
"They're very cheap to produce and very sensitive," Rains said. "Dogs take months to train and they need a specific handler. Wasps can be trained on the spot."