Vehicle emissions impair pollinator ability to locate flowers

A systematic review of 22 experimental studies published in ‘Frontiers in Ecology and the Environment’ indicates that vehicle emissions, specifically nitrogen oxides (NOx) and ground-level ozone, significantly impair the ability of pollinators like bees and moths to locate flowers.

These pollutants alter or weaken the scents emitted by plants, making it difficult for insects to navigate. The research, led by James Ryalls of the University of Reading, measured this impact through ‘pollinator performance,’ which tracks how efficiently animals find and pollinate blooms. On average, increased ozone levels reduced pollinator performance by approximately 42 percent, while nitrogen oxides caused a 46 percent reduction. When both pollutants were present simultaneously, pollinator performance decreased by an average of 68 percent, though researchers noted this combined effect is slightly less than the sum of individual effects due to chemical interactions between the gases.

The findings suggest potential risks to crop yields, particularly for specialized insect species that rely on specific floral scents for orientation.