Large-scale study 'shows neonic pesticides harm bees'

[nitpicker]

http://www.bbc.com/news/science-environment-40382086

Large-scale study 'shows neonic pesticides harm bees'

By Rebecca Morelle
Science Correspondent, BBC News

29 June 2017

From the section Science & Environment

The most extensive study to date on neonicotinoid pesticides concludes that they harm both honeybees and wild bees. Researchers said that exposure to the chemicals left honeybee hives less likely to survive over winter, while bumblebees and solitary bees produced fewer queens. The study spanned 2,000 hectares across the UK, Germany and Hungary and was set up to establish the "real-world" impacts of the pesticides. The results are published in Science.

Neonicotinoids were placed under a temporary ban in Europe in 2013 after concerns about their impact on bees. The European Commission told the BBC that it intends to put forward a new proposal to further restrict the use of the chemicals.
(snip)

However, Bayer, a major producer of neonicotinoids which part-funded the study, said the findings were inconclusive and that it remained convinced the pesticides were not bad for bees.
(snip)

The pan-European trials took place across 33 sites. Bees were exposed to winter-sown oilseed rape that had been treated with two different types of neonicotinoids - Bayer's clothianidin and Syngenta's thiamethoxam - as well as untreated oilseed rape. For bumblebees and solitary bees, the researchers said that in the UK, Hungary and Germany, higher concentrations of neonicotinoid residues found in nests resulted in fewer queens. The scientists also found a type of neonicotinoid called imidacloprid in the wild bee nests. This pesticide was not used in the study, and the team said its presence suggested that despite the 2013 ban, the chemicals were lingering in the environment.

For honeybees, the scientists concluded that in the UK and Hungary, exposure to neonicotinoids meant that hives were at risk of dying out over the winter. Prof Pywell said: "In the UK, we had high hive mortality." In Hungary, colonies fell by 24% over winter.

However in Germany, the scientists found there were no harmful effects on overwintering honeybees. They believe this may be because bee diseases are less prevalent in Germany and the insects also have a wider range of flowers to forage on.
(snip)