Decline of wild bee populations in England linked to controversial pesticides

The decline of wild bees across England is linked to the use of controversial pesticides, according to scientists.

Research led by the Centre for Ecology and Hydrology found that species of wild bees exposed to oilseed rape crops treated with neonicotinoids suffered population decline of up to 30% between 2002 and 2011.

The pesticide is the subject of an EU-wide two-year ban amid concerns over its harmful impact on bees, such as colony growth, and damaging their ability to forage and navigate.

The research looked at changes in occurrence of 62 species with oilseed rape cropping patterns across England between 1994 and 2011, and examined data from 31,818 surveys across more than 4,000 square kilometres of land.

It found an average population decline across all species of 13%, of which more than half (7%) was linked to the use of neonicotinoids between 2002 and 2011 - after the pesticide came into widespread commercial use.

Species which forage on oilseed rape were three times more seriously affected on average than those which did not.

Analysis of the data also found that neonicotinoids caused declines of more than 20% for the five most seriously affected species.

Dr Nick Isaac, who co-authored the paper, said: "The negative effects that have been reported previously, they do scale up. They scale up to long-term, large-scale, multi-species impacts that are harmful."

A spokeswoman for the Department for Environment, Food and Rural Affairs said: "The use of neonicotinoids is restricted and we are committed to ensuring pesticides are available only when the scientific evidence shows they do not pose unacceptable risks to the environment.

"Bees and other pollinators are vital to the diversity of our environment and food production, which is why we are leading on a nationwide strategy to better protect them.

"We are encouraging farmers to provide the food and habitats pollinators need on their land, as well as promoting simple actions the public can take such as cutting grass less often and growing pollen-rich plants."