When it comes to zeroing in on nectar-rich flowers, worker honey­bees rely heavily on their expert sense of smell. But new research suggests pollution from diesel exhaust may fool the honey­bee’s “nose,” making their search for staple flowers all the more difficult.

In a paper published recently in Scientific Reports, English scientists concluded that two components of diesel exhaust — nitric oxide and nitrogen dioxide — could alter the odor of the many chemicals that combine to give a flower its signature smell.

This phenomenon, researchers said, could hinder or prevent honey­bees from reaching their target flowers and, in the process, inhibit the pollination of the world’s principal food crops.

The research comes at a time of great concern over the fate of pollinator insects.

Globally, their numbers have been on the decline, and the potential consequences for humans are great.

The economic value of pollination across the planet has been estimated at more than $200 billion a year, and 70 percent of the world’s food crops rely on this process, according to lead study author Robbie Girling, a chemical ecologist at the University of Southampton.

While study authors acknowledged that their conclusion was the result of manipulating synthetic odors, not field observations, they said the disruption of natural odors by man-made pollution could have far-reaching effects.

“In nature honeybees use a combination of visual stimuli and floral odors to locate a flower for the first time,” authors wrote.

“Degradation of an odor source by pollution is likely to be more pronounced at distance from the flower, where concentrations of the odors are lower,” they wrote. “This could result in greater dependence upon other senses critical for foraging behavior, such as vision, to compensate for the reduction in olfactory stimuli.”

— Los Angeles Times