Episode Transcript
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Speaker 1 (00:02):
Welcome to brain stuff from how Stuff Works, Hey, brain stuff,
Lauren vocabam here. Back in two entomologists Joe Lewis and
Jim Tomlinson joined in a project that for the first
time uncovered the ability of an insect to learn through association.
It was at the time not only novel, it was
(00:22):
an out and out revelation an insect, in this case,
the parasitic wasp, which feeds on and eventually kills certain
agricultural pests, could learn in a most basic way I
think Pavlov's dogs, except smaller and buzzier. From that study
and other similar research by for example, DARPA, the U.
S Department of Defense Advanced Research Projects Agency, we have
(00:44):
spun forward to the point where honeybees now have successfully
sniffed out long buried land mines in Croatia. That's a
long way from some thirty years ago when Lewis and
Tomlinson released their findings in Nature magazine to the astonishment
of many. Louis said, you talked at training an insect period,
and you get the look the I start narrowing. It
(01:04):
just doesn't make sense. So how did they start making
sense of it? Let's talk about associate of learning. The
whole idea behind this is fairly simple, even if no
one dreamed decades ago that insects could do it. With
Pavlov's dogs, when an outside stimulus a bell is often cited,
was associated with food, the dogs salivated. The dogs learned
(01:24):
intuitively that the bell meant food was coming for the Lewis, tumlins,
and wasps. Various odors that the wasps didn't normally recognize,
like vanilla or chocolate, or mixed with something that was
associated with the pests that these parasitic wasps were trying
to make their hosts. After a very short time, the
wasps associated the vanilla or whatever with the insects that
(01:46):
they wanted to attack, and thus would fly toward the odor.
It took less than five minutes to train the wasps, which,
like bees and dogs, have all factory senses thousands of
times more powerful than a humans. As the studies continued,
new researchers linked the smell of various chemical compounds and
explosives to food. Today, honey bee trained for just two
(02:07):
days could associate the smell of explosives with food and
seek out that smell too. Big advantages to training insects
to track odors rather than say a dog. They learn faster,
and there's a lot more of them to teach. But
releasing a swarm of wasps or bees onto a battlefield
or even a now quiet meadow in Croatia that may
be littered with minds has its challenges. Of course, tracking
(02:30):
the insects is foremost among them. It's impossible, as timlins
In points out, to put ships on each of them,
and you can't, as Louis says, put Alisha on a bee. Still,
scientists can trace the insects movements in at least small numbers,
through devices like drones and webcams, and something early researchers
called a wasp pound. Louis's waspound, about the size of
(02:51):
a large coin, contains five wasps, a tiny camera, and
a computer fan that pulls air through a small hole
in the bottom of the device. When the hound comes
near the target, smell the wasps, Lewis says, cluster around
that little hole, like pigs to a trough. Another problem
researchers face is scale. Training one wasp or one b
(03:12):
at a time can be laborious. Scientists have come up
with methods to train more than that, but insects, like people,
learn at different rates, so mass learning is not as accurate.
In addition, bad weather or anything that disrupts the insexibility
to smell can cause difficulties. Research is continuing. Tomlinson and
Lewis never envisioned be signiffiicg out bombs. Tomlinson is a
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professor of entomology at Penn State and Lewis a retired
professor and a research entomologist with the U S Department
of Agriculture in Tifton, Georgia. They were looking for ways
to control pests biologically rather than with pesticides, and in
fact they were very successful at it. Along with UK
scientist John Pickett, Lewis and Tomlinson one the two thousand
(03:56):
eight Wolf Prize for Agriculture, considered by many as a
type of Nobel Prize in the field. From the official
announcement on the Wolf Foundation website, they were awarded the
prize quote for their remarkable discoveries of mechanisms governing plant
insect and plant plant interactions. Their scientific contributions on chemical
ecology have fostered the development of integrated pest management and
(04:18):
significantly advanced agricultural sustainability. Whether their work eventually will help
form the basis of a widespread practical use of bees
and wasps in sniffing out bombs or drugs remains to
be seen. Even they have some doubts. Tomlinson said, you
can train insects to find a mine, that's not a problem.
But then you release them into the field to find
(04:38):
a mine. How do you track them unless someone comes
up with a small chip so that you can track
them with some electronic means. I don't see how in
the world you can use them, and says Lewis, to
move it from the lab to the actual field. You
have to scale it up and refine it. But we
clearly can see that it can be practical in development.
It's technically feasible. It's all on valid sign it's the
(05:00):
ability is there. It's about the demand for it and
putting the infrastructure in place for that. Scientists have been
trying to find ways to harness the remarkable power of
smell for years. Bees, some believe, have such strong abilities
that they can smell out illnesses, even cancer. A Spanish
designer went so far as developing a prototype bowl complete
(05:20):
with honey bees that you can breathe into to see
how the bees react as a sort of proto diagnosis,
and tests are being done in California with cancer detecting
dogs too. Today's episode was written by John Donovan and
produced by Tyler Clang. Brain Stuff has merch now. You
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(05:43):
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