Since 2013, a European Union (EU) moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects.
Since 2013, a European Union (EU) moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects. Yet researchers from the CNRS, INRA, and the Institut de l’Abeille (ITSAP) have just demonstrated that residues of these insecticides—and especially of imidacloprid—can still be detected in rape nectar from 48% of the plots of studied fields, their concentrations varying greatly over the years. An assessment of the risk posed to bees, based on health agency models and parameters, has revealed that for two out of five years, at least 12% of the fields were sufficiently contaminated to kill 50% of the bees and bumblebees foraging on them. The researchers’ findings are published in Science of the Total Environment (28 November 2019).
The role of neonicotinoids in the decline of bees led to a 2013 EU moratorium limiting the use of three insecticides—clothianidin, imidacloprid, and thiamethoxam—on crops attracting pollinating bees. In September 2018, this was followed by a total ban on their application to any outdoor crop in France. Yet neonicotinoids are frequently detected on wildflowers1 and untreated crops,2 suggesting their dispersion within the environment after agricultural use.
To investigate this further, researchers from the Chizé Centre for Biological Studies (CNRS / La Rochelle University); INRA units Abeilles, Paysages, Interactions et Systèmes de Culture (APIS) and Abeilles et Environnement (AE); and ITSAP looked for and quantified neonicotinoid residues in nectar from 291 plots (536 samples) of winter rape for the five years following adoption of the moratorium, from 2014 to 2018.
Read more at Centre National De La Recherche Scientifique