Scientists train honeybees to detect explosives
Initially, the concept seems too incredible to be possible — train a common honeybee to physically respond to the distinctive smell of specific explosives, then develop a method for measuring or observing that response in order to use the bee’s reaction to the smell of explosives as a natural explosives detector. As incredible as it may seem, Laboratory scientists recently created such a detector under the Stealthy Insect Sensor Project.
According to Tim Haarmann of Molecular Microbiology and Immunology (B-1), principal investigator for the Los Alamos Stealthy Insect Sensor Project, the project applies old knowledge to a pressing new problem. “Scientists have long marveled at the honeybee’s phenomenal sense of smell, which rivals that of dogs,” said Haarmann. “But previous attempts to harness and understand this ability were scientifically unproven. With more knowledge, our team thought we could make use of this ability.”
By studying and training bees, Haarmann and members of the Los Alamos Stealthy Insect Sensor Project team has been able to harness the honeybee’s exceptional olfactory sense by using the bees’ natural reaction to nectar, a proboscis extension reflex (sticking out their tongue) to record an unmistakable response to a scent. Using Pavlovian techniques, researchers were able to train the bees to give a positive detection response via the PER when exposed to vapors from TNT, C4, and TATP explosives.
The Stealthy Insect Sensor Project was born out of a global threat from the growing use of improvised explosive devices or IEDs, especially those that present a critical vulnerability for American military troops in Iraq and Afghanistan, and as an emerging danger for civilians worldwide. Current strategies to detect explosives are expensive and, in the case of trained detection dogs, too obtrusive to be used very discreetly. With bees however, they are small and discreet, offering the element of surprise. They're also are inexpensive to maintain and even easier to train than dogs. As a result of this need, initial funding for the work was provided by a development grant from the Defense Advanced Research Projects Agency.
The Laboratory team began with research into why bees are such good detectors, going beyond merely demonstrating that bees can be used to identify the presence of explosives. By looking at such attributes as protein expression, the team sought to isolate genetic and morphological differences between those bees with good olfaction and those without. They also determined how well bees could detect explosives in the presence of potentially interfering agents, such as lotions, motor oil, or insect repellant. In addition, the team studied structural units in the honeybee’s antenna and looked for biochemical and molecular mechanisms that could advance their ability to be trained and retain their training for longer periods of time.
The Stealthy Insect Sensor Project team includes Haarmann, Kirsten McCabe of Molecular Microbiology and Immunology (B-1), and Robert Wingo of Chemical Science and Engineering (C-CSE). Additional members include Caroline Weldon and Priya Dighe of B-1; Sara Maurer of Hydrology, Geochemistry, and Geology (EES-6); and Rhonda Robinson and Sherri Sherwood of Ecology and Air Quality (ENV-EAQ).
