Wasps Used to Detect Explosives
MELISSA BLOCK, host:
The next generation of bomb or drug-detecting technology could be the wasp. Scientists are training wasps to detect specific odors. They train the insects by exposing them to a target odor and then giving them sugar water so they associate the smell with their treat. The researchers have developed a device called the Wasp Hound. The wasps are put inside a plastic cylinder with a vent hole at one end, a fan that pulls air in and a tiny Web camera inside hooked up to a computer to monitor the wasps' reaction. If they detect what they've been trained to smell, they'll converge around the air hole `like pigs to a trough,' says one of the inventors, Joe Lewis, who's a research entomologist. He says the wasps have been trained to pick up a wide range of smells.
Mr. JOE LEWIS (US Department of Agriculture): 24DNT, which is a breakdown product of TNT; cadaverine, which is a chemical that's associated with decaying flesh. For forensic purposes, we've shown that they show odors associated with marijuana. In other words, we have found that they have a very broad sense of detection capabilities; essentially it's unlimited.
BLOCK: How long does it take to train these wasps to detect these new smells?
Mr. LEWIS: Well, very quickly. You can train them in as short a time as, say, five minutes, because the training protocol is to let them taste sugar water while they smell an odor. And you do that for 10 seconds and repeat it three times with a small break in between, and they've learned it.
BLOCK: Have you ever found a wasp that just really couldn't learn?
Mr. LEWIS: They all learn. We have found that some are quick learners and respond more aggressively than others.
BLOCK: I guess you're working against one fact of nature here, which is that wasps have a very short life span. You're not going to have these detectors with you for that long.
Mr. LEWIS: That is true. You know, there are advantages and disadvantages of this compared to, say, a dog. The advantage is that you can produce them by the thousands or more, and you can train them quickly and you can use them in a rather disposable manner. The disadvantage is that they don't live long, a couple of weeks. And we have to deal with shortcoming, but we can produce them very inexpensively and train them very quickly.
BLOCK: Mm-hmm. And you can't rub their bellies.
(Soundbite of laughter)
Mr. LEWIS: Well, it would be a very tedious process.
(Soundbite of laughter)
Mr. LEWIS: And you can't carry them around on a leash.
BLOCK: Is there, do you think, some broader lesson here about insects, about the power of smell?
Mr. LEWIS: Oh, yes. There once was a staying `The deeper the well, the sweeter the honey.' Indeed, there was a time--and let me say, early in my profession that if I had talked about insects having this capability, I would have been laughed out of my profession.
BLOCK: Is that right?
Mr. LEWIS: But as we move along and find what we're seeing, that learning in this highly sophisticated ability to integrate taste and smell and to quickly link and utilize these type things is a much primitive ability than we had imagined. In their world and on their territory, they are as sophisticated as we are. And they've been around a long, long time.
BLOCK: I'll never look at them quite the same way.
Mr. LEWIS: Each day, I find that I look at them with much greater respect. In many ways, all these things are rather sacred.
BLOCK: Joe Lewis, thanks very much.
Mr. LEWIS: Yeah. Well, thank you, Melissa.
BLOCK: Joe Lewis is a research entomologist with the US Department of Agriculture in Tifton, Georgia.
ROBERT SIEGEL (Host): This is NPR, National Public Radio.