Bees suffering a ‘significant reduction’ in pollination ability due to air pollution, study finds

In short:

Air pollution can disrupt pollination and the regulation of pest insects by 40 per cent, a study published in Nature Communications shows.

Pollutants such as ozone impact bees and other bugs’ ability to locate flowers and crops.

What’s next?

An author of the study says farmers have a crucial role to play in working to reduce the stressors on beneficial insects.

Bees and other bugs crucial to a diverse ecosystem experience a significant decline in performance after exposure to polluted air, according to a new study.

The findings indicate increased ozone and other air pollutants are yet another stressor on pollinators, which play a crucial role in ensuring global food supply.

Ozone, naturally occurring in the upper atmosphere, develops harmfully at ground level due to chemical reactions from man-made activities such as burning fossil fuels.

The data from a study in Nature Communication, which was collected on 40 different insect species across 19 countries, pointed towards pollinators and beneficial predator species experiencing an almost 40 per cent drop in productivity, while pest insects were not significantly impacted.

Robbie Girling from the University of Southern Queensland co-authored the study and said it was a double blow for food security.

“Pests are essentially performing just as they would do normally in an unpolluted environment, so what you’ll see is those pests will continue to be as damaging as they are now,” he said.

“But as pollution levels increase, we see a reduction in those natural enemies of the pests, which is going to be a big concern for growers.”

Professor Girling said the difference in impact came down to the beneficial insects’ reliance on their sense of smell.

“What happens is the flowers’ odours are being degraded [by pollutants] and insects use these smells to locate them,” he said.

 “And if those flowers are releasing chemicals … they’re liable to be reacted with by ozone, which will either completely remove them or change them chemically so the insect can’t respond anymore.”

Many Australian-grown food crops such as almonds, mangoes, avocados, and berries rely on pollinators for fruit set. 

Farmers of self-pollinating crops such as wheat and barley also rely heavily on beneficial predator insects like wasps to naturally manage pest insects such as aphids.

What to do?

With the results of the latest study, Professor Girling stressed the importance of farmers taking action.

“What we have to do is relieve even a little bit of that stress these insects are under,” he said.

“[That might be] the ability to leave a bit of spare land for natural habitat to provide [beneficial insects] with pollen and nectar close by to keep them going.”

He also recommended farmers consider their local pollinator populations when it came to  the insecticide treatments they used on their crops, and the times they applied those treatments.

“It just takes small steps by everybody to reduce as many stressors as they can,” Professor Girling said.

Aussie farmers on front foot

With advances in agricultural research and generational knowledge, experienced broadacre cropping agronomist Paul McIntosh believes Australian farmers are already looking to help beneficial insects. 

“We’re not way behind the eight ball, we are already providing good environmental conditions for our beneficial insects,” he said.

“Farmers know now bees are a major plus for our farming systems. We are not back in the 1980s, we are in 2024 and we’ve learnt a lot.”

He said the use of synthetic pyrethroids, which kill every insect in a crop, had fallen dramatically with farmers turning to soft chemicals. 

“As the years have gone by we’ve developed chemicals that still do the job on the pest insect but don’t destroy the populations of those beneficial insects that might be in the crop,” Mr McIntosh said.

Organic farming the answer?

While Mr McIntosh acknowledged the role of biological insecticides in organic farming, he did not think a full phase-out of chemicals was feasible in large-scale Australian food and fibre production.

“Certainly I think organic farmers are doing a good job. However, I believe if we’re moving away from that harsh chemistry and getting more into softer chemicals and strategic spraying we are doing a good thing,” he said.

Professor Girling reiterated it would come down to many achievable steps forward.

“It’s all about being able to sustainably farm financially, as well as to sustainably farm in terms of the environment,” he said.

“We just all need to work together.”