Bees and other beneficial bugs are disproportionately harmed by air pollution compared to crop-destroying pests, a new study published in Nature Communications has found.
Researchers from the University of Reading and the University of Southern Queensland (UniSQ) analysed data from 120 scientific papers to understand how 40 types of insects in 19 countries responded to air pollutants like ozone, nitrogen oxides, sulfur dioxide and particulate matter.
Beneficial insects – including pollinators like bees and some moths and butterflies – experienced up to 39 per cent decline in performance after exposure to elevated air pollution levels. In contrast, plant-eating aphids and other pests were not significantly impacted.
UniSQ Centre for Sustainable Agricultural Systems Director Professor Robbie Girling, a co-author of the study, said the findings had important implications for global agriculture and food security.
"This is yet another stressor that is affecting our global pollinator populations, in combination with things like land use change, habitat destruction, and climate change," Professor Girling said.
"This combination of stressors is putting increased pressures on pollinator populations and therefore we need to look to ways to alleviate this range of stressors to help give our pollinators a greater fighting chance."
University of Reading Research Fellow Dr James Ryalls, who led the study, said air pollution was an "underappreciated threat" to the insects that make our lives easier.
"The bees that pollinate our flowers and the wasps that provide natural pest control are at risk of further decline if air pollution levels are not addressed," Dr Ryalls said.
"We are facing a 'lose-lose' scenario where air pollution harms helpful insects without affecting pests, potentially leading to greater crop damage, reduced yields and less food on supermarket shelves.
"Insect populations are already declining globally, and even moderate levels of air pollutants are harming beneficial insects, meaning we need stricter air quality regulations to protect nature's hardest workers."
The researchers suggest that beneficial insects – such as bees and wasps – are more affected by air pollution due to their reliance on scent-based communication. Many beneficial insects use airborne chemical signals to locate flowers, find mates, or hunt prey.
Air pollutants can chemically alter these scent trails or interfere with insects' ability to detect them, essentially disrupting their sensory landscape.
In contrast, many pests rely less on long-distance scent cues and more on direct contact or visual cues, making them less vulnerable to air pollution's effects on airborne chemical signals.
The study focused on how air pollution impacts various aspects of insect behaviour and biology, including feeding, growth, survival, reproduction, and ability to locate food sources. Of all these factors, insects' ability to find food was most severely impaired by air pollution, declining by about one-third on average.
