Glyphosate dangerous to beetles as well as plants
The herbicide could harm bacteria that insects rely on.
The saw-toothed grain beetle (Oryzaephilus surinamensis) on oat flakes. Credit: Julian Kiefer, Johannes Gutenberg-Universität Mainz
The commonly used herbicide glyphosate might not be just bad news for bees. New research has found it could have broader ramifications for the survival of other insects by affecting their bacterial allies.
The study, published in the journal
Communications Biology, showed that glyphosate inhibits a biochemical pathway in bacteria that was previously only thought to affect plants, making them unable to supply the growing sawtoothed grain beetle with essential nutrients.
Credit: Julian Kiefer, Johannes Gutenberg-Universität Mainz
Saw-toothed grain beetles live in a symbiotic association with bacteria. Their bacterial partners provide important building blocks for the formation of the insect s exoskeleton, which protects the beetles from their enemies as well as from desiccation. In a new study, a team of scientists from the Johannes Gutenberg University in Mainz, the Max Planck Institute for Chemical Ecology in Jena, and the National Institute of Advanced Industrial Science and Technology in Japan demonstrates that glyphosate inhibits the symbiotic bacteria of the grain beetle. Beetles exposed to the weedkiller no longer receive the building blocks they need from the bacteria. The study shows that glyphosate has the potential to harm insects indirectly by targeting their bacterial partners and thus to contribute to their decline (