Dr Ben Woodcock, Centre for Ecology & Hydrology

“Neonicotinoids are extensively applied to agricultural crop seeds and, being systemic pesticides, are then transferred into the plant tissues as the crop germinates and grows. They reduce pest damage on these crops, but can also affect beneficial insects, including bees, that feed on pollen and nectar. Although a huge number of studies have already identified negative effects of these pesticides on bees, many of them are laboratory based and don’t therefore reflect the real world. However, a new study by CEH* has provided fresh evidence in this debate. Importantly, we looked at the effects of neonics

in real farms – at 33 sites across the UK, Germany and Hungary. Interestingly, we didn’t find the same effects in each country. For example, overwintering honeybees in the UK and Hungary fared far worse when exposed to neonics in the previous year. In Germany, we found either no effect or, in one case, even a short-term positive effect on egg numbers. Where we found negative effects, honeybees were more diseased and had poorer diets dominated by oilseed rape. Bees in Germany were always healthier, had a diverse diet, and fed on a crop that flowered late, so may have contained fewer pesticide residues. We also found that wild bees had lower reproduction levels when concentrations of neonics were high in their nests. The study highlights that the effects of neonics may depend on context. A good agricultural environment rich in wildflowers (particularly early in the year) and new approaches to honeybee health may mean that bees are better able to deal with exposure to neonics, but this needs further research. The EFSA will determine later this year whether the temporary ban on neonicotinoid use on mass-flowering crops in the EU should be extended indefinitely.” • Dr Ben Woodcock is lead author of the report by the CEH