Wasp hounds “sniff” explosives and illegal drugs

Drug smugglers and terrorists may soon meet their match: a handheld chemical detector powered by trained wasps or bees. Nicknamed “The Wasp Hound” the prototype tool houses five parasitic wasps that react to the smell of explosives, illegal drugs, and plant diseases. In theory, the insects’ movements set off an alarm to alert authorities. Although this news dates a few years back we thought it should take its place on our website because it is a representative of nature’s alternative to our technological achievements.

In the wild the wasps use their antennae to detect corn borer caterpillars, which the parasites use to hatch and grow their young. The wasps lay single eggs in the caterpillars. As the young mature, they feed on their hosts, which eventually weaken and die.

Known for their keen sense of smell, parasitic wasps don’t sting humans and are as small as flying ants. Researchers believe the insects are nearly ideal for the task of sniffing out bombs. Unlike dogs, the wasps can be trained within 30 minutes and bred by the thousands, providing a near limitless supply. The Wasp Hound grew out of decades of study of Microplitis croceipes, a parasitic wasp species native to Georgia.

“They are an incredibly versatile type of system. We’ve really just scratched the surface,” said Glen Rains, a biological engineer at the University of Georgia, in Tifton, who co-invented the device.

The Wasp Hound was co-invented by W. Joe Lewis, an expert on parasitic wasps who works as an entomologist with the USDA Agricultural Research Service in Tifton. In the 1970s, Lewis and his colleagues discovered that the wasps locate the caterpillars by detecting a chemical they leave behind them. Later research revealed that the wasps’ olfactory system was directly linked to their taste receptors and that the insects learn to associate certain smells with food or with corn borers.

Lewis and Rains, the Georgia-based researchers, received funding in 1998 and began actively working on the Wasp Hound. They hope it will make it to market in five to ten years. The Wasp Hound is a tube made of PVC pipe. At one end is a clear plastic chamber, about 5cm in diameter and 2.5cm deep, where the wasps are housed.

“It’s like a cap that you can take on and off,” Rains explained. The chamber has vent holes, a fan, and a miniature camera connected to a computer. When the wasps aren’t working “they just randomly walk around” in their chamber, Rains said. But when the wasps encounter a smell they have been trained to recognize, the hungry insects congregate near the odor source, hoping for food.

The mini-cam tracks their movement, sending pictures to the computer, which analyzes the images and triggers an alarm within 30 seconds. The insects are so sensitive that they react less or more strongly, depending on the strength of the smell they are exposed to, Rains says. The wasps can be used for 48 hours. After they complete their shift “we just let them go,” Rains explained.

The Wasp Hound has only been tested under laboratory conditions. It needs to be rigorously tested in cold weather, dusty conditions, and other real-world situations before it will be ready for widespread use, Rains said.