Pollution may make it even harder for bees to pollinate plants. Researchers have found that car exhaust fumes can mask the smell of flowers, making it more difficult for bees to learn individual floral scents.
Bees use their noses to sniff out the best flowers for pollen and nectar – they fly from flower to flower, transferring pollen and seeds, ensuring our food continues to grow. Aside from producing honey, bees enable the growth of apples, oranges, avocados and broccoli in this way.
Sticking out their tongues
According to Ryan James Leonard of the University of Sydney, in lab tests bees were able to quickly learn that a whiff of floral scent is usually followed by a taste of sugar. They then come to expect it, sticking out their tongues for sweetness after catching a blossomy sniff. However mix the smell with exhaust fumes and it takes bees a lot longer to develop that behaviour. Leonard tested the bees with several different floral scents. The bees could still identify linalool, (a natural chemical found in lots of flowers) after being mixed with exhaust fumes but other chemicals proved tougher.
Puff Puff Pass
Usually bees learnt to stick out their tongues for sugar after just two puffs of scent. But it took them three puffs to identify the ingredient myrcene when it was mixed with exhaust fumes. It took them four puffs when dipentene was mixed with exhaust fumes and it took them six puffs to learn the complex smell of a geranium.
Ryan James Leonard told the International Congress of Entomology that he hoped his research would show how living alongside traffic affected the life of bees. His findings echo a number of other studies that showed how pollutants impact bees’ behaviour. In 2013, scientists discovered how diesel made oilseed flowers smell different to bees. In 2015 it was discovered that effect of diesel fumes on flower scent was even greater than previously thought. Research from Reading University found that in polluted environments, diesel fumes may be reducing the availability of almost half the most common flower odours that bees use to find their food.
Lead author Dr Robbie Girling said: “Bees are worth millions to the British economy alone, but we know they have been in decline worldwide. “People rely on bees and pollinating insects for a large proportion of our food, yet humans have paid the bees back with habitat destruction, insecticides, climate change and air pollution. “This work highlights that pollution from dirty vehicles is not only dangerous to people’s health, but could also have an impact on our natural environment and the economy.”