Neonicotinoid pesticides harm bees and wild bees, say results of a study published in the journal Science. These conclusions were obtained on the ground in three European countries.
Researchers from the Center for Ecology and Hydrology (CEH) assessed the impacts of neonicotinoid agricultural pesticides on bees and wild bees across Europe. The experiment, carried out in the UK, Germany and Hungary, exposed three bee species to winter rapeseed crops treated with seed coatings containing neonicotinoid clothianidin, Bayer CropScience or thiamethoxam from Syngenta. Neonicotinoid seed coatings are designed to kill pests such as the beetle.
Neonicotinoids destroy bee colonies
The researchers found that exposure to the treated crops reduced the winter survival rate of honey bees in two of the three countries. In Hungary, the number of settlements fell by 24% the following spring. In the UK, survival has been generally low and lowest in hives where bees have been in contact with rapeseed treated with clothianidin.
In contrast, in Germany where the hives were larger, researchers observed few signs of disease and fewer adverse effects on bee colonies.
“The neonicotinoids studied caused a reduced ability for the three bee species to establish new populations the following year, at least in the UK and Hungary,” explained Dr Ben Woodcock who suggested “that the divergent impacts on honeybees between countries may be associated with interactive factors, including the availability of alternative floral resources for the bees to feed on, as well as the general health of the colonies, with the Hungarian and British bees getting sicker. “
After reading these findings, “one can no longer continue to claim that neonicotinoids in agriculture are not harmful to bees,” said David Goulson, professor of biology at the British University of Sussex in the UK who does not did not participate in the research.
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