Food supplements for honeybees could help the insects better withstand temperature stresses linked to a changing climate, early research suggests.
Lab study shows cold tolerance boost
Scientists found that worker bees fed a mixture of probiotics and inulin, a plant-derived prebiotic, survived prolonged cold exposure better than bees given an ordinary sugar diet. The study was conducted on isolated caged bees, not full colonies.
But the supplements offered little meaningful protection against extreme heat. In laboratory tests at 40C, all the bees died within days, regardless of diet, though some of those receiving higher supplement doses survived slightly longer.
Temperature extremes are becoming increasingly common globally as the burning of fossil fuels causes the planet to heat, though the link between the climate crisis and unusual cold in some regions is complex.
Expert insights on colony-level effects
Dr Najmeh Sahebzadeh, an associate professor at the University of Zabol, Iran, and the lead scientist in the study, said: “As nutritional shortages, pathogens and extreme weather continue to compound one another, the study is relevant not only to pollinator health but also to broader ecosystem stability and the services that food systems depend on.”
The study’s findings suggest nutrition may give managed bees an additional line of defence against some extreme temperatures.
Peter Graystock, an assistant professor in human and animal health at Imperial College London, who was not involved in the study, said: “It is interesting that this suggests microbes may be important for changes in climate, which isn’t something that has been looked at very much.”
Limitations of lab-based research
The researchers and independent experts made clear the study was carried out on isolated caged bees, whereas full colonies in outdoor hives would respond to heat in ways that isolated workers cannot.
“Colony-level behaviours … wouldn’t necessarily be expressed in a cage study,” said Prof Giles Budge, an independent expert in crop and honeybee health at Newcastle University.
“A good example is that when honeybees fan their wings together, they can move air through the nest and reduce its temperature. That can mean a behaviour intervenes before the thermal stress causes mortality.”
Graystock added: “Honeybees will change their behaviour to try to cool down their hive. But there comes a point where there is only so much they can do.”
Broader implications for agriculture
As the climate crisis worsens alongside accelerating biodiversity loss, honeybees face mounting pressures that threaten their immediate health and their long-term survival.
“Honeybees play a vital role in modern agriculture,” said Graystock. “Many crops depend on insect pollination, and managed honeybee colonies can be moved to where and when they are needed to support crop production.”
He acknowledged the potential for supplements to help bees survive in colder conditions, but said more research was necessary.
“Winter is one of the riskiest periods for honeybee colonies because bees can’t leave the hive to forage and must rely on stored resources to survive,” said Graystock. “This study suggests nutritional and microbial supplements might help bees through some of these cold challenging periods, although further research is needed to see whether those benefits occur at the colony level in the real world.”
Supplements not a substitute for habitat conservation
The researchers also warned against treating supplements as a substitute for healthier landscapes.
“Supplementation deals with the immediate physiological stress, not the underlying causes like shrinking forage, fragmented habitat and pesticide exposure,” said Sahebzadeh. “It really needs to sit alongside broader conservation-minded beekeeping, not replace it.”
Graystock added that improvements in floral diversity and countryside management would leave bees less dependent on artificial feeding. “I’d like to think nutritional supplements would not become the norm, because it would suggest that we don’t have healthy landscapes where bees can have healthy food,” he said.
