Bumblebees exposed to the world’s most popular type of weedkiller found it harder to learn and remember colours linked to rewards – which could undermine their ability to find food for the colony.
Marjo Helander at the University of Turku in Finland and her colleagues investigated how glyphosate, in this case in the herbicide Roundup Gold, affected buff-tailed bumblebees (Bombus terrestris) in colour-based learning and memory tests.
Over five rounds, bees chose between different-coloured artificial flowers, five containing a sugar reward and five a bad-tasting quinine solution.
Unexposed …