"A new study reveals how pollutants from human activity impact their ability to locate flowers"
"Along any busy roadway, the remnants of car exhaust hang in the air, among them nitrogen oxides and ozone. These pollutants, which are also released by many industrial facilities and power plants, float through the air for hours to years. Scientists have long known that these chemicals are harmful to human health. But now, a growing body of evidence suggests that these same pollutants also make life harder for insect pollinators and the plants that rely on them.
Different types of air pollutants react with the chemicals that make up a flower’s scent, altering the amount and composition of the compounds in a way that impedes a pollinator’s ability to locate flowers. In addition to looking for visual cues such as a flower’s shape or color, insects depend on a scent “map,” a combination of odor molecules unique to each flower species, to locate their desired plant. Ground-level ozone and nitrogen oxides react with the floral scent molecules, creating new chemicals that function differently.
“It’s fundamentally changing the scent that the insect is looking for,” said Ben Langford, an atmospheric scientist for the UK Centre for Ecology and Hydrology who researches this issue.
Pollinators learn to associate a unique combination of chemicals that the flower releases with that specific species and its associated sugary reward. When these fragile compounds come into contact with highly reactive pollutants, the reactions alter the number of floral scent molecules as well as the relative amount of each type of molecule, fundamentally changing the scent."