A new study demonstrates that diesel exhaust interferes with honeybees' ability to locate flowers, which could have consequences for the pollination of crops. (Joe Raedle/Getty Images)
Humans aren’t the only ones who like to stop and smell the flowers.
Bees have a highly sensitive sense of smell, and they use it to find flowers with high concentrations of nectar. But a recent study shows that exhaust from diesel fuel — which is gaining in popularity due to its fuel efficiency — reacts with floral aromas, making it difficult for bees to find and pollinate flowers, according to Quartz.
Scientists at University of Southampton made a mixture of chemicals to synthesize the smell of rapeseed oil, the BBC reports, which they taught honeybees to recognize. They then added realistic diesel exhaust to the mix and found that chemical components of the floral odor reacted with mono-nitrogen oxide, a component of the exhaust also known as NOx. In tests, the bees were much less responsive to smells after the exhaust had been mixed in.
“Our results suggest that that diesel exhaust pollution alters the components of a synthetic floral odor blend, which affects the honeybee's recognition of the odor,” Tracey Newman, who conducted the study, told Phys.org. “This could have serious detrimental effects on the number of honeybee colonies and pollination activity."
Honeybee pollination is crucial to worldwide production of crops, and the bees get their food from the flowers they pollinate. But since 2006, bees have been abandoning their hives en masse in what has come to be known as Colony Collapse Disorder, a problem that as yet has no clear cause or solution and that threatens an estimated $15 billion worth of crops in the United States alone, according to the Natural Resources Defense Council.
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The new Southampton study is not explicitly linked to CCD, the researchers point out. “However,” they told Quartz, “while our comprehension of how these factors impact directly upon honeybee health is advancing, additional as yet undiscovered mechanisms are likely to be involved in honeybee declines.”
Biologist James Nieh of the University of California San Diego agreed. “Most research on such contaminants has focused on pesticides," he told BBC News. “But bees are subject to a much wider variety of pollutants and contaminants. The influence and potential synergy of these pollutants with pesticides should be studied.”
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This macro image is part of a new USGS collection that catalogues native North American bees. (Flickr/Sam Droege/USGS Bee Inventory and Monitoring)