Bees Losing Sense of Smell

It has been reported by neuroscientists at the University of Southampton that traffic fumes render the scent of flowers barely recognisable to honeybees and could have a serious impact on their ability to find food. The report states that reactive pollutants in diesel destroyed key chemicals in the odour of oilseed flowers making them smell different to the bees.

Honeybees have a sensitive sense of smell and an exceptional ability to learn and memorise new odours. The effect of diesel fumes on flower scent could have serious detrimental effects on the number of honeybee colonies and pollination activity.

Three quarters of the world's food crops rely on bees and other natural pollinators, a service valued at £135bn a year globally. But there have been serious declines in natural pollinators in recent decades. A combination of factors has been blamed including the huge loss of the flower-rich habitats that sustain bees as well as disease and the impact of agricultural insecticides. And now it appears that traffic fumes are adding to the problem.

Honeybees are very, very selective on what they home in on. They do not go randomly from flower to flower. The team of scientists found that it was the highly reactive nitrogen oxides (NOx) that chemically altered the smell by removing key chemicals within a minute of exposure in the laboratory environment.

Emissions from diesel regularly exceed the limits for nitrogen dioxide and emissions from petrol vehicles often contain even higher levels of NOx. These nanoparticle pollutants, already known to harm human health, may also be affecting bees.