Diesel fumes disorient honeybees

Diesel exhaust fumes alter the flowery smells that guide bees when they forage, potentially sending them off course and putting the food-growing 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 render flowers undetectable to bees.

This, in turn, threatens the insects' role as pollinators of human food crops.

"Somewhere in the region of 70 percent of world crops require pollination services, and ... about 35 percent 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.

"This isn't just about a bee getting confused because there is a new smell around. This is actually that the chemistry of the odor itself is being chemically altered," she explained.

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 percent of pollination by insects, but their numbers have slumped in Europe and the United States in the past 15 years because of a phenomenon dubbed colony collapse disorder.

The mysterious plague, often characterized by a rapid loss of adult worker bees, has been attributed to everything from agricultural pesticide use to a loss of wild bee habitat, a virus or fungus, mites — or a combination that may now also include diesel fumes.

The disorder has killed off about 30 percent of bees annually since 2007.

Agence France Press