The super sensitive sensors of insects' antennae can detect vapor molecules in the low parts per billion, so a UC Davis researcher is seeking to train bees to pick up the subtle scent of plant disease before it can be seen by the human eye.

UC Davis plant pathology post-doc Andrew Sutherland designed an experiment that utilizes bees' sense of smell to alert farmers they may or may not need a fungicide spray to manage disease on their crops.

Sutherland's use of the classical conditioning method - like that used on Pavlov's dogs  - was described in a 2 1/2-minute video on ZDnet.com. Bees are restrained in tiny harnesses and, after being exposed to the smell of an infected grape leaf or berry, are fed a bit of sugar water.

"In time, the bees begin to associate the odor with a sugar reward," Sutherland says on the video.

Later, the trained bees are taken to the field inside a prototype box designed by Sutherland's collaborators at Los Alamos National Lab. When the bees detect the odor inside the box, they respond and the information is relayed to a computer.

The goal of the research is development of an early warning system for plant diseases so farmers can better plan fungicide applications, Sutherland said.