Glyphosate, the world's most widely used herbicide, disrupts honeybee behavior and brain chemistry despite decades of assumptions about its safety, according to new research.
Scientists discovered that the chemical affects bees through a different biological mechanism than previously understood. While glyphosate targets an enzyme absent in honeybees, it alters neurotransmitter levels in their brains, disrupting normal foraging behavior.
Exposed bees reduced foraging by 13 percent within just three days of contact with glyphosate. The researchers documented changes in brain chemicals linked directly to behavioral control. These neurological shifts occur even though the herbicide's primary mechanism of action should theoretically spare bees entirely.
The implications extend beyond individual insects. A 13 percent drop in foraging across an entire hive compounds rapidly. Reduced food collection threatens honey production, diminishes pollination services, and jeopardizes colony long-term viability. Honeybees already face multiple stressors including habitat loss, parasites, and pesticides.
Glyphosate's widespread application makes this finding particularly relevant. Farmers spray it on crops globally, and residues persist in agricultural landscapes where bees forage. The chemical has been detected in flowering plants, pollen, and nectar that bees consume.
This research challenges the conventional safety assessment that excluded glyphosate from bee-harming pesticides. Regulators classified it as safe specifically because it targets an enzymatic pathway absent in animals. The new data reveals that assumption was incomplete.
The study adds glyphosate to a growing list of chemicals known to harm bees through indirect neurological pathways rather than direct toxicity. Neonicotinoid insecticides similarly disrupt bee navigation and immunity despite different chemical structures.
The findings underscore how pesticide safety evaluations require testing across multiple biological mechanisms,