Researchers point out that the common herbicide causes bee deaths

One of the most used herbicides in the United States could be the indirect cause of the rapid decline in the population of bees.

Researchers at the University of Texas have discovered that glyphosate, an active ingredient in the popular Weedkiller Roundup brand, could contribute to the widespread death of honey bees and native bees worldwide.

The study was published in the journal Proceedings of the National Academy of Sciences.

Deadly effects of glyphosate

Glyphosate is an effective herbicide because it interferes with an enzyme found in plants, but has long been considered non-toxic to humans and animals. However, researchers at the University of Texas exposed the bees to glyphosate and discovered that the herbicide had significantly reduced the healthy gut microbiota.

Snodgrassella alvi, a species of bacteria that transforms food and defends bees against pathogens, was less abundant three days after glyphosate exposure. Bees with altered intestinal microbiomes are more likely to die when they are exposed to Serratia marcescens, an opportunistic pathogen known to kill bees around the world.

"Studies in humans, bees, and other animals have shown that the gut microbiome is a stable community that resists infection by opportunistic invaders," says Nancy Moran, a professor at the University of Toronto. University of Texas and one of the authors of the study. "So, if you disrupt the normal, stable community, you're more susceptible to this invasion of pathogens."

Native bumblebees also have the same species of intestinal bacteria as bees. Although untested, Moran added that the herbicide could have the same effect on bumble bee populations.

The use of glyphosate in ordinary households is not the only reason why bees are dying at an alarming rate. However, the authors hope that their findings will guide farmers, landscapers and homeowners in choosing a more environmentally friendly herbicide.

"We need better guidelines for the use of glyphosate, especially with regard to the exposure of bees, because at the moment, the bees are not injured by the herbicide," he said. said Erick Motta, graduate student and co-author of the study.

Bees are dying

Previous studies have revealed that bees are dying at an alarming rate due to climate change, habitat loss, the emergence of foreign pests and the widespread use of pesticides. Between April 2015 and April 2016, US beekeepers reported losing 40% of their colonies. In the United Kingdom, beekeepers have lost about 17% of their colonies. The same trend is felt around the world.

The importance of bees to the world can not be stressed enough. Most plants depend on bees to pollinate naturally and produce flowers or food.