Flower power: bumblebees ferry natural protection from bloom to bloom

University of Warwick research has shown how pollination could be combined with a new, environmentally friendly approach to protecting crops from bacterial disease.

As they fly about their usual business of pollinating flowers, bumblebees could help protect fruit trees from disease by carrying a natural treatment directly to where it is needed. Crop scientists have shown that bees can deliver naturally occurring viruses called bacteriophages, or phages, to cherry blossom as they visit the flowers. The approach could help growers protect fruit crops more precisely while reducing reliance on conventional chemical treatments.

Dr Mojgan Rabiey, a plant pathologist specialising in biological crop protection at Warwick Crop Centre, said: “Phages are found almost everywhere in nature, including soil, water and on plants. Unlike viruses that infect people, animals or plants, phages only infect and kill bacteria, and individual phages are highly specific about which bacteria they attack. That means we can select phages that specifically target disease-causing bacteria without harming beneficial microbes around them.

“But finding an effective phage is only half of the challenge. We also need to deliver it to exactly where and when the plant needs protection – and that is where the bumblebees come in.”

From hive to blossom

The idea of using bumblebees emerged while Dr Rabiey and her team were visiting orchards to collect samples and search for naturally occurring phages capable of tackling cherry canker, one of the most damaging bacterial diseases affecting cherry production.

Dr Rabiey said: “Many cherry growers already use bumblebees to improve pollination, and I started to wonder whether the bees flying from flower to flower could also carry phages directly to the blossoms we want to protect.”

The researchers developed a system in which bees walk through a tube containing specially formulated phage powder as they leave their hive, picking it up on their bodies in the same way they pick up pollen on flowers. In experiments using both real and artificial cherry flowers, the native British buff-tailed bumblebees (Bombus terrestris audax) successfully transferred the phage to up to 88% of flowers, where the phages significantly reduced bacterial populations.

Dr Rabiey said: “The most exciting part was seeing nature working with nature. Phages are natural enemies of bacteria, and bumblebees are natural pollinators. Bringing those two systems together gives us a completely different way to think about protecting plants.”

A natural defence for more crops and trees

Dr Rabiey added: “Our long-term goal is to give growers practical, environmentally friendly ways to manage bacterial diseases while reducing reliance on conventional pesticides and antibiotics. The idea isn't limited to cherries and has the potential to be adapted to other crops where flowers are an important route for bacterial infection.”

The Warwick team is dedicated specifically to developing phages as biological controls for bacterial diseases of crops and plants.

Research Fellow Dr Shannon Greer said: “Developing the phages is only useful if we can turn them into something that growers can realistically use, and our bumblebee phage delivery doesn't require specialist equipment to apply. We have shown that the approach works experimentally, and the next step is to begin piloting the treatment with growers.”

The Warwick Crop Centre team is exploring how phages could help protect fruit crops including cherry, apple, and pear, forestry trees, and vegetable crops from bacterial disease.

ENDS

Notes to editors

Dr Mojgan Rabiey is an Associate Professor at the University of Warwick and a plant pathologist researching biological control technologies for bacterial diseases of crops and trees. Her work uses bacteriophages and beneficial microbes to improve disease control and reduce dependence on conventional crop protection products.

The research is published in Biological Control: Bee-mediated delivery of bacteriophage for biocontrol of the cherry canker pathogen Pseudomonas syringae pv. Syringae.

DOI: https://doi.org/10.1016/j.biocontrol.2025.105922

Images:

For more information please contact:

Ann Baylis, Media and Communications Officer

ann.baylis@warwick.ac.uk | +44 (0) 7425 722087

About the University of Warwick

Founded in 1965, the University of Warwick is a world-leading institution known for its commitment to era-defining innovation across research and education. A connected ecosystem of staff, students and alumni, the University fosters transformative learning, interdisciplinary collaboration and bold industry partnerships across state-of-the-art facilities in the UK and global satellite hubs. Here, spirited thinkers push boundaries, experiment and challenge convention to create a better world.