Diesel fumes throw honeybees off the trail, says study

PARIS: Diesel exhaust fumes alter the flowery smells that guide bees when they forage, potentially sending them off course and putting the foodgrowing industry at risk, a study said Thursday.

Honeybees rely heavily on their sense of smell to locate flowers from which they harvest life-giving nectar — transferring pollen grains from one bloom to another in the process.

The new research shows that diesel exhaust fumes from cars, tractors or power generators can chemically alter the smell of flowers and render them undetectable to bees. This, in turn, threatens the insects’ crucial role as a key pollinators of human food crops.

“Somewhere in the region of 70% of world crops require pollination services, and... about 35% of our current food production is reliant on pollination,” study co-author Tracey Newman of the University of Southampton told a press conference ahead of the report’s release in the journal Nature Scientific Reports.

Pollination services have an estimated economic value of $208 billion a year.

For the study, Newman and a team created a synthetic odour blend mimicking the complex chemical mix that make up the smell of oilseed rape flowers.

The synthetic blend of eight chemicals was released into a sealed glass vessel with clean air, and another that contained diesel exhaust at levels similar to rush hour roadside fumes

Within a minute, the chemicals alpha-farnesene and alpha-terpinene, which comprised 72.5% and 0.8% of the blend respectively, were “rendered undetectable” in the diesel-polluted air.

Next, the team tested whether bees would notice the difference.

If the foraging bees are unable to find nectar, the entire hive will suffer for a lack of food — as will the plants that depend on pollination to reproduce.

“And without efficient, effective pollination, there are going to be consequences for human health,” said Newman.

Bees account for some 80% of pollination by insects, but their numbers have slumped in

Europe and the United

States in the past 15-odd years