December 20, 2017

Double dose for bees

In a paper published today in the Proceedings of the Royal Society B: Biological Sciences, a team of researchers from Italy and the US record their study of the effects on honey bees of agriculture that exposes the insects to both poor nutrition (low quality nectar) and pesticides (neonicotinoids).

“Our results provide the first demonstration that these stressors can synergistically interact and cause significant harm to animal survival,” report the researchers. “These findings have implications for pesticide risk-assessment and pollinator protection, and emphasise the importance of nutrition.”

Rothamsted Research was asked to comment on inquiries from the media:
“How does intensive agriculture reduce the quality/quantity of nutrients for bees?”

“Does this new research mean the threat to bees posed by pesticides could be greater than previously imagined?”

“What significance does this have for on-going policy debates around the use of pesticides?”

Comment from Rothamsted Research

Jonathan Storkey, Plant Ecologist and Leader of Achieving Sustainable Agricultural Systems (ASSIST),one of Rothamsted’s five strategic research programmes:
“The paper provides further evidence for the negative effects on bees of exposure to sub-lethal concentrations of neonicotinoids. However, the novelty of the work is to put this effect in the context of additional stresses on bee survival and fitness, in this case decreasing nutritional quality of their food sources.

“Interestingly, sub-lethal and field realistic doses of neonicotinoids did not significantly reduce survival when bees were supplied with ample supplies of nutritionally rich food. It was only when bees were stressed by nutritionally poor diets that a synergistic negative effect of the pesticides was observed.

“The results emphasise the need to consider the wider ecological requirements of non-target organisms when assessing the environmental risks of pesticides and the potential to mitigate harm through the provision of supplementary sources of pollinator habitat such as wild flower field margins.”

Read the paper in Proceedings of the Royal Society B: Biological SciencesNeonicotinoid pesticides and nutritional stress synergistically reduce survival in honey bees (Open Access).

Article source: Rothamsted Research