|02 October 2018
THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
Glyphosate Shown to Increase Honeybee Susceptibility to Infections
Increased mortality of honey bee colonies has been attributed to several factors but is not fully understood. The herbicide glyphosate (commonly sold as Roundup) is claimed to be innocuous to animals, including bees. However, a new study has found that exposing bees to glyphosate alters the bee gut microbiota and increases the insects’ susceptibility to deadly infections by pathogens. This is because some of the key beneficial bacteria in bees’ guts have the particular enzyme that is targeted by glyphosate.
Bees rely on a specialized gut microbiota that benefits growth and provides defense against pathogens. The study demonstrated that the relative and absolute abundances of dominant gut microbiota species decreased in bees exposed to glyphosate at concentrations documented in the environment. Young worker bees exposed to glyphosate exposure died more often when later exposed to a common bacterium. Thus, exposure of bees to glyphosate can perturb their beneficial gut microbiota, potentially affecting their health and effectiveness as pollinators.
The findings show that glyphosate, whose use has risen with the expansion of GM herbicide-resistant crops,may be contributing to the global decline in bees, along with the loss of habitat. Other research has shown that honeybee larvae grew more slowly and died more oftenwhen exposed to glyphosate. An earlier study showed the exposure of adult bees to the herbicide at levels found in fields “impairs the cognitive capacities needed for a successful return to the hive”.
With best wishes,