Scientists have found for the first time that neonicotinoid pesticides can harm honey bees in the real world.
The major new study from the Centre for Ecology and Hydrology (CEH) found that pesticides called neonicotinoids can cause harm to bees, a development that is likely to increase calls for a ban of the chemicals across Europe.
The UK — which has long lobbied against a ban — could make its own rules on pesticide use after Brexit.
Conservative MEP Julie Girling recently tried unsuccessfully to derail the Commission’s efforts to introduce an outright ban in the EU Parliament.
The finding is particularly significant because the study was funded in part by pesticides giants Bayer and Syngenta.
The hotly anticipated research, published in the journal Science this evening, also discovered that exposure to the nicotine-based chemicals can reduce the reproductive success of three different bee species — honey bees, bumblebees and the red mason bee.
With £3 million in funding from the chemical companies and additional money from Natural Environment Research Council (NERC), the researchers were able to conduct a large scale, field-realistic experiment across three different European countries — UK, Germany and Hungary.
Previous experiments showing that neonicotinoids cause harm to bees have been criticised by industry because of their limited scope and test conditions not mimicking real life.
The researchers exposed three bee species to winter oilseed rape crops treated with two types of neonicotinoids, manufactured by Bayer and Syngenta.
The researchers found that neonics affected bees in different ways from country to country, with the impact of the chemicals more marked in Hungary and the UK than in Germany, where neonics were found to have no impact on honey bees.
Overall, clothianidin, manufactured by Bayer, was found to have a more profound impact on bee health.
CEH scientists acknowledged that the results of the study were nuanced.