A study confirms that neonicotinoids are responsible for the decline of wild bees

The connection between pesticides and massive die-offs of bees has been confirmed. “Our results show that neonicotinoids are harmful to wild bees”.

That there is a correlation between the use of pesticides and honeybees’ decline is already known. But up to now this has always been demonstrated by short-term laboratory studies on commercially bred species.

Neonicotinoids have caused bees in the UK to decline by 10% © Joe Raedle / Getty

Now, for the first time, a detailed study that finds a correlation between the use of neonicotinoids and the decline of many species of bees has been carried out. It is entitled “Impacts of neonicotinoid use on long-term population changes in wild bees in England” and was published by Nature Communications in August 2016. It demonstrates how in the UK, from 1994 to 2011, it was detected a loss of species occupancy, especially in the areas where rapeseed was cultivated using this type of insecticides.

“Our results show that neonicotinoids are harmful to wild bees”, said Nick Isaac, researcher at the Centre for Ecology and Hydrology (CEH) in Wallingford, UK.

Bees and pesticides, now the link is proved

Isaac and his team have studied the impact of neonicotinoids on the populations of 62 species of wild bees throughout England during 18 months.

Protest against the use of pesticides © Simone D’Angelo / Getty Images

And their results leave no room for doubt: at least 34 species of bees feeding on rapeseed fields declined by 10% because of this insecticide. Three times the amount observed in bees feeding on other flowers. So, basically, half of the die-offs of wild bees are attributable to the use of chemicals in the fields.
“Historically, if you just have oilseed rape, many bees tend to benefit from that because it is this enormous foraging resource all over the countryside”, one of the authors of the study Ben Woodcock stated. “This correlation study suggests that once it’s treated with neonicotinoids up to 85%, then the bees are starting to be exposed and it’s starting to have these detrimental impacts on them”.

A rapeseed field © Frank Bienewald / Getty

Now it’s time for EFSA to act

EFSA (European Food Security Authority) could use this study when in January 2017 it will have to express its opinion on these insecticides. In past years it had already declared that clothianidin, thiamethoxam, imidacloprid are dangerous insecticides. The use and sale of seeds treated with plant protection products, containing these active substances, has been banned in Europe in 2013.

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