MILWAUKEE – Toxins, bombs, dead bodies and more may one day be found by using a "Wasp Hound" – not a dog, but a contraption containing wasps trained to zero in on scents, according to research from the University of Georgia and U.S. Department of Agriculture.
Wasps used in the study were trained to identify a specific odor in five minutes and are cheaper than trained dogs.
Using creatures other than dogs in odor detection is not new.
Rats, honeybees and even fish have all been successfully trained to detect various toxic chemicals and diseases.
Wasps caught the researchers' attention because they are similar to honeybees, which have been successfully marketed as odor detectors in the United Kingdom.
The wasps are much less expensive than trained dogs and more sensitive than some methods of chemical detection, the researchers say.
The wasps are trained to detect specific odors and are placed in a small hand-held device called a Wasp Hound, which is capable of sounding or flashing an alarm when the target odor is found.
"I think it has great potential," said Sam Wasser, a professor of biology at the University of Washington, who was not involved in the study. "We often underestimate the utility of scent information. Living organisms have spent hundreds of thousands of years evolving sophisticated ways to perfect scent detection."
These wasps are extremely dependent on their sensitive olfactory system to find food and hosts for their larvae.
The female wasp forages for caterpillars to lay her eggs, and the wasps learn about their environment as they forage, said Glen Rains of the University of Georgia, the lead researcher of the study. It was published online in the September issue of Biotechnology Progress.
In the study, the wasps were trained to identify a particular odor in five minutes.
Because a wasp's life span is just 14 days, the insects would not survive if they could not quickly learn to find odors for food and larval hosts, said Rains, a professor of biological and agricultural engineering.
The wasps are trained by associated learning. They are allowed to smell the target odor and are given food. When they smell the odor again, they think it is food or a host for their eggs, Rains said.
Because the wasps are highly sensitive to environmental fluctuations, they are placed in the cup-sized Wasp Hound, which is made of PVC pipe and has an odor inlet hole.
To monitor the wasp's behavior, a tiny camera is placed inside and connected to a laptop computer.
"When the wasps sense the odor, they walk toward the center of the hound where the odor is coming from," Rains said.
The research is intriguing and advances the idea that insects can be trained to find very low concentrations of chemicals, said Robert Jeanne, a professor of entomology at the University of Wisconsin-Madison.
The Wasp Hound is being used to search for a toxin that grows on corn and peanuts.
Wasps also have the potential to detect explosives. In a previous study they were trained to detect 2,4-dinitrotoluene (2,4-DNT), a chemical used in specific explosives.
Other forensic applications could include grave-site and body detection.
Different types of vegetation or a slight depression in the soil may indicate a potential grave site, said Jerome Guerts, director of the Wisconsin Crime Laboratory in Madison.
The Wasp Hound requires a specific search area, said Rains. Therefore, if there are several potential grave sites identified, the Wasp Hound might be useful for confirmation.
If there isn't a specific search area, dogs are used because they are able to smell from a far distance and can accurately survey large areas, said Wasser, who uses search dogs in his research at the University of Washington.
But search dogs can be expensive and time-consuming – it can take six months and cost up to $15,000 to train a search dog.
Wasps can be trained in five minutes and have the same sensitivity as dogs.
The Wasp Hound device costs $125.
Researchers developed the software and are aiming to have it run on a hand-held computer.
"The hope is to have something very inexpensive," Rains said. He believes that in five to 10 years, there could be a viable commercial Wasp Hound.
The Wasp Hound will need to tested on a larger scale.
"If they come up with an effective means of searching that is inexpensive, people will use it," Wisconsin's Guerts said. "The next step will be to get the judge to accept it."