A Canadian field study suggests that the negative effects of neonicotinoids on bee colonies is worse than previously thought. Jim Drury reports.
STORY: Neonicotinoid pesticides are harming bee colonies more than previously thought. So say researchers at Toronto's York University and Laval University, Montreal. SOUNDBITE (English) YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV SAYING: "One of the really surprising things we found is that honeybees were exposed to neonicotinoids on average for three months, which is previously unreported and we only thought that honeybees were getting hit once - either during corn plantation or perhaps during corn bloom. But we found that honeybees collected pollen with neonicotinoids for three months on average." For an entire bee-keeping season researchers studied 55 colonies - near fields of corn grown from neonicotinoid-treated seeds and away from farmland. Neonicotinoids are water soluble and the team found them spreading from fields into the surrounding environment, to plants that bees find attractive. SOUNDBITE (English) YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV SAYING: "We found that, in fact, honeybees rarely collected pollen from corn or soy, which are the target plants, and often the pollen came from things like willow and clover." Neonicotinoids were found before some corn crops were planted, suggesting they'd stayed in the environment from previous years. There were other worrying findings. SOUNDBITE (English) YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV SAYING: "We tested one herbicide - Linuron - and one fungicide - Boscalid - which were the most common things we found, along with neonicotinoids. On their own the herbicide and fungicide did not kill bees at all but when we combined the fungicide with the neonicotinoid the mixture was twice as toxic as just the neonicotinoid alone." In 2013 the European Union introduced a temporary ban on three major neonicotinoids on bee-attractive crops. This could soon be extended and made permanent. Bees pollinate much of our food supply and campaigns to ensure the insects thrive are stepping up.