Honeybees are being killed by the world’s most popular weedkiller Roundup, new research has revealed.
The active ingredient in Roundup is glyphosate which causes bees to lose beneficial bacteria in their guts.
This leaves them more susceptible to infection and death from harmful bacteria.
Scientists believe this is evidence that Roundup, which is made by Monsanto, might be contributing to the decline of honey bees and native bees around the world.
‘We need better guidelines for glyphosate use, especially regarding bee exposure, because right now the guidelines assume bees are not harmed by the herbicide,’ said Erick Motta, the graduate student from the University of Texas at Austin who led the research.
‘Our study shows that’s not true.’
Because glyphosate interferes with an important enzyme found in plants and microorganisms, but not in animals, it has long been assumed to be nontoxic to animals, according to the paper published in the journal Proceedings of the National Academy of Sciences.
However, this latest study shows that it alters a bee’s gut microbiome.
This is the ecosystem of bacteria living in the bee’s digestive tract, including those that protect it from harmful bacteria.
Glyphosphate means they are less able to fight infection.
Researchers exposed honeybees to glyphosate at levels known to occur in crop fields, yards and roadsides.
They painted the bees’ backs with coloured dots so they could be tracked and later recaptured.
Three days later they observed that the herbicide significantly reduced healthy gut microbiota.
Of eight dominant species of healthy bacteria in the exposed bees, four were found to be less abundant.
The hardest hit bacterial species, Snodgrassella alvi, is a critical microbe that helps bees process food and defend against pathogens.
The bees with impaired gut microbiomes also were far more likely to die when later exposed to an opportunistic pathogen.