It looks like scientists have finally managed to find a link between the world’s most common weed killer and the increasing number of bee deaths. According to a recent study, conducted by researchers from The University of Texas at Austin, glyphosate, which is the active component of Roundup, destroys some good bacteria in bees’ guts, making them more prone to various diseases and death from dangerous bacteria.
Glyphosate is toxic for bees after all
The study, which was published in the journal Proceedings of the National Academy of Sciences, proves that glyphosate affects the health of honey bees and native bees, contrary to the common belief that it only interferes with an enzyme crucial for plants and microorganisms. However, through a negative impact this substance has on the bee’s gut microbiome, it weakens the bee’s immunity, which often leads to a fatal infection.
How was the study conducted
In order to find out if exposure to glyphosate has any effect on bees, the scientists used the level of this substance that exists in crop fields. The bees exposed to glyphosate had their backs marked with colored dots, so that they could be easily identified later on. After three days, the gut microbiota in recaptured bees has been heavily reduced by the herbicide. Half of the bacteria species decreased in numbers, including the most important one, Snodgrassella, which helps with digestion and strengthens the immune system.
These bees were later exposed to Serratia marcescens, a potentially dangerous pathogen. What the scientists observed was that, compared to about a 50% survival rate of the bees with healthy gut, 90% of the bees affected by glyphosate died within eight days after they were exposed to the pathogen.
Taking the results of the research into consideration, the scientists recommend that we should not spray herbicides containing glyphosate on flowering plants that bees are likely to visit.