Honeybees Ability to Smell Affected by Diesel Fumes

Honeybees are adversely affected by diesel pollution as it hinders their ability to sniff out flowers and pollinate.

University of Southampton researchers led the study and found that diesel exhaust fumes change the chemical profile of floral aroma molecules, a change that could affect honeybees' ability to locate, identify and recognize a potential food source.

"Bees need to decipher the chemical messages they're getting (from flowers) to be able to home in on the flowers they know will give the best yield (of nectar)," study author and Southampton neuroscientist Tracey Newman told Victoria Gill of BBC News.

Researchers also exposed the changed chemical mix to honeybees, which could not identify it.

"Honeybees have a sensitive sense of smell and an exceptional ability to learn and memorize new odors," Newman noted. "NOx gases represent some of the most reactive gases produced from diesel combustion and other fossil fuels, but the emissions limits for nitrogen dioxide are regularly exceeded, especially in urban areas."

"Our results suggest that that diesel exhaust pollution alters the components of a synthetic floral odor blend, which affects the honeybee's recognition of the odor," he added. "This could have serious detrimental effects on the number of honeybee colonies and pollination activity."

Researchers conducted a test that involved teaching bees to associate the smell of a particular chemical with being given a drop of sugary liquid.

Bees respond to the taste of the sugar by sticking out their tongues - just as they do when drinking nectar from a flower. So after a few trials where the scent of the odor is followed closely by a sweet drop of liquid, the bees stick out their tongues as soon as they detect the scent.