Air pollution confuses butterflies and bees study by University of Reading finds

A bee lands on a flower in a city environment. Credit: PA Images

Common air pollutants from both urban and rural environments may be reducing the pollinating abilities of insects, new research by the University of Reading has shown.

Pollutants such as diesel exhaust fumes and ozone, have been linked to the reduction in pollinators such as bees and butterflies.

Scientists from the University of Reading, the UK Centre for Ecology & Hydrology, and the University of Birmingham found that there were up to 70% fewer pollinators, up to 90% fewer flower visits and an overall pollination reduction of up to 31% in test plants when common ground-level air pollutants were present.

The study, published in the journal Environmental Pollution, is the first to observe a negative impact of common air pollutants on pollination in the natural environment.

The theory is that the pollutants react with and change the scents of flowers, making them harder to find.

Pollinators play a vital role in agricultural food production. Credit: PA Images

Observations revealed there were 62-70% fewer pollinator visits to the plants located in polluted air.

This reduction was seen in seven pollinator groups, particularly bees, moths, hoverflies and butterflies.

There were also 83-90% fewer flower visits by these insects, and ultimately a 14-31% reduction in pollination, based on seed yield and other factors.

Dr Robbie Girling, Associate Professor in Agroecology at the University of Reading, who led the project, said: “We knew from our previous lab studies that diesel exhaust can have negative effects on insect pollinators, but the impacts we found in the field were much more dramatic than we had expected.”

Dr James Ryalls, a Leverhulme Trust Research Fellow at the University of Reading, who conducted the study, said: “The findings are worrying because these pollutants are commonly found in the air many of us breathe every day. We know that these pollutants are bad for our health, and the significant reductions we saw in pollinator numbers and activity shows that there are also clear implications for the natural ecosystems we depend on.”

Such findings could have wide ranging implications because insect pollination delivers hundreds of billions of pounds worth of economic value every year.

It supports around 8% of the total value of agricultural food production worldwide, and 70% of all crop species, including apples, strawberries and cocoa, rely on it.