Golden State Poppy
2005-12-04 21:36:58 UTC
By ELLIOTT MINOR, Associated Press Writer
Sat Dec 3,11:49 AM ET
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 up to 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 U.S. Department of Agriculture entomologist 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 University of Georgia
agricultural engineer 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 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 trained wasps, they
needed a way to contain them while monitoring their reactions to odors.
Enter the Wasp Hound - a 10-inch-long plastic 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 the
behavior of 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. Otherwise, they
just hang out inside the capsule.
They can work for as long as 48 hours, then they're released to live
out their remainder of their two-to three-week life span.
"What we have ... is a technology-free organism that you can quickly
program and use in a highly mobile way," said Lewis, who believes the
Wasp Hound could be used to search for explosives at airports, locate
bodies, monitor crops for toxins and detect diseases such as cancer
from the odors in a person's breath.
"They're very cheap to produce and very sensitive," Rains said of the
wasps. "Dogs take months to train and they need a specific handler.
Wasps can be trained on the spot."
Rains believes the Wasp Hound could be available for sale in three to
five years. He and Lewis are still exploring ways to breed more wasps
and to train hundreds simultaneously.
"We've done enough on it to know it's technically feasible to do that,"
Lewis said. "It's just a matter of completing and refining the
Lewis believes many other types of invertebrates - bees, other types
of parasitic insects, even water bugs - can be trained to sniff out
"It's opened a whole new resource for invertebrates as biological
sensors," he said.
Other scientists also are working to harness the sniffing power of
In 2002, the Pentagon considered fitting sniffer bees with transmitters
the size of a grain of salt to locate explosives and relay that
information wirelessly to laptop computers.
A British firm, Inscentinel Ltd., sells trained bees and mini-hives
where the insects' response to scents from natural and man-made
chemicals can be monitored. The company says the system can be used to
screen for explosives, drugs, chemical weapons, land mines and for food
Jerry Bromenshenk, a research professor at Montana State University, is
using bees for mine detection. The bees congregate over mines or other
explosives and their locations are mapped using laser-sensing
"Insects and their antennae have an olfactory system that is pretty
much on a par with a dog," Bromenshenk said. "They're a whole lot more
plentiful and a lot less expensive to come by."
Bromenshenk said bees may be more appropriate for open areas, while the
Wasp Hound may be better in buildings.
"The difference is that we let our bees free fly," he said. "That's not
good in confined areas like an airport."