The most commonly used herbicide might also indirectly kill bees, as reported in a new study carried out by the researchers at the University of Texas at Austin, published this week in the journal Proceedings of the National Academy of Sciences. According to the scientists, a widely used weed killer known as Roundup leads to bee deaths due to its high-content of glyphosate which affects the insects’ gut beneficial bacteria exposing them to infections.
“We need better guidelines for glyphosate use, especially regarding bee exposure, because right now the guidelines assume bees are not harmed by the herbicide. Our study shows that’s not true,” said Erick Motta, the study’s leading author.
Since glyphosate, the primary active substance in Roundup herbicide, does not interfere with animals, but only with the enzymes found in plants and microorganisms, such weed killers have been considered safe for animals and humans, as well.
A glyphosate-based common herbicide linked to bee deaths
In their study, the scientists exposed bees to glyphosate at the same levels that are supposed to be present in crops and roadsides. After three days, the bees’ healthy gut bacteria populations diminished significantly exposing the insects to the lethal Serratia marcescens pathogen, as well as other infections that could lead to death.
“Studies in humans, bees and other animals have shown that the gut microbiome is a stable community that resists infection by opportunistic invaders. So if you disrupt the normal, stable community, you are more susceptible to this invasion of pathogens,” stated Nancy Moran, the study’s co-author.
With their study’s results in mind, both authors of the study, Erick Motta and Nancy Moran, recommend farmers and authorities to stop spraying Roundup, a common glyphosate-based herbicide, on flowering plants bees are usually pollinating. In conclusion, according to this recent study, a common herbicide based on glyphosate is linked to bee deaths.