An 18-year study of more than 60 wild bee species in Britain found that populations declined when the bees foraged on crops treated with neonicotinoid pesticides, according to the Washington Post. “The study provides some of the first evidence that the effects of neonicotinoid exposure can scale up to cause major damage to bees,” the Post said.
The study, published in the journal Nature Communications, was significant in terms of its length and number of bee species studied.
Until now, most of the research on the effects of pesticides has been limited to short-term, small-scale studies, many of them performed in laboratory settings, Ben Woodcock, an ecological entomologist at the Centre for Ecology and Hydrology in the UK and the paper’s lead author, told the Post. While previous studies focused on just a few species, the new study relies on field data collected on many species over nearly two decades.
The researchers compared bees that foraged on pesticide-treated oilseed rape crops — the same plants commonly used to make canola oil — and bees that forage on other plants, the Post said. “Oilseed rape crops are widely treated with neonicotinoids around the world, and the practice began on a wide scale in the UK starting in 2002. It’s the biggest mass flowering crop in the UK, where neonicotinoids have been widely applied, according to Woodcock, making it an ideal subject for the study,” the Post said.
Overall, the researchers found that the bee decline was three times more severe in bees that foraged on oilseed rape plants than in bees that didn’t forage on the pesticide-treated crops.
The European Union banned on the use of multiple neonicotinoid pesticides in 2013, citing their potential danger to bees, although a few exemptions have since been granted in the UK, the Post said. Neonicotinoids are still widely used in many other places around the world, including in the United States. Insect pollinators are estimated to support 9.5 percent of global food production, the study noted.