Glyphosate targets undesired weeds—as well as honeybees

The most widely sprayed herbicide in the world kills honeybees, according to a new report.

Glyphosate, an herbicide and active ingredient in Monsanto’s (now Bayer’s) Roundup weed killer, targets enzymes long assumed to be found only in plants. The product is advertised as being innocuous to wildlife. But some bacteria also use this enzyme, including a microbiome found in the intestines of most bees. When pollinators come in contact with glyphosate, the chemical reduces this gut bacteria, leaving bees vulnerable to pathogens and premature death.

“The bee itself has no molecular targets from glyphosate,” Nancy Moran, a biologist at the University of Texas at Austin and a coauthor of the study, told Environmental Health News. “But its gut bacteria do have targets.”

Moran and other scientists liken glyphosate exposure to taking too many antibiotics—and upsetting the balance of good bacteria that supports immunity and digestion.

“We all know that glyphosate is an antibiotic. It’s very toxic to bacteria. It’s even patented as an antibiotic,” says Nathan Donley, a senior scientist at the Center for Biological Diversity. “But very few researchers have actually dived into this issue. The good thing is, that’s starting to change.”