- Title: Neonic pesticides 'worse for bees than previously thought'
- Date: 4th September 2017
- Summary: TORONTO, CANADA (JULY 26, 2017) (REUTERS) BEES IN HIVE YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV OPENING HIVE VARIOUS OF BEES IN HIVE (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. So then we tested the pollen to see where the neonicotinoids were coming from and 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." SANTIAGO, CHILE (FILE) (REUTERS) VARIOUS OF EMPTY BEE HIVES VARIOUS OF DEAD BEES BEE ON PLANT TORONTO, CANADA (JULY 26, 2017) (REUTERS) (SOUNDBITE) (English) YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV SAYING: "This indicates that neonicotinoids are slipping into the system and persisting there throughout the year because one of the things we also found was that neonicotinoids were present in honeybee colonies before corn was planted. So it's probably was there from last year's planting." BRUSSELS, BELGIUM (FILE) (REUTERS) VARIOUS OF PROTEST OUTSIDE EU COMMISSION BUILDING, WITH PROTESTERS HOLDING BANNERS READING: "EU SAVE OUR BEES" TORONTO, CANADA (JULY 26, 2017) (REUTERS) (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." VARIOUS OF TSVETKOV OPENING HIVES AND BEES IN HIVES VARIOUS OF TSVETKOV BEING STUNG ON THE HAND (SOUNDBITE) (English) YORK UNIVERSITY PHD STUDENT NADIA TSVETKOV SAYING: "I think one of the really important things we take away from this study is the knowledge is that even though the health effects that we found were mild, because the neonicotinoids persist in the system for so long the health effect really accumulates. The other thing I think that's very important to take away is that we should never test the chemical alone - we should always find out what's happening in the field and what kind of interaction effects we have - and testing that." VARIOUS OF TSVETKOV HANDLING BEES / BEES IN HIVE
- Embargoed: 18th September 2017 10:48
- Keywords: Bees neonicotinoids pesticides herbicide fungicide York University Laval University
- Location: TORONTO, CANADA / SANTIAGO, CHILE
- City: TORONTO, CANADA / SANTIAGO, CHILE
- Country: Canada
- Reuters ID: LVA0016X6KZ17
- Aspect Ratio: 16:9
- Story Text:The effect of neonicotinoids on bee colonies has divided scientists, with opponents of the pesticides saying they damage pollinator numbers, while a minority dismiss the effects.
A new Canadian field study suggests the problem is worse than previously thought.
The research team, from the York University in Toronto and Laval University in Montreal, studied 55 colonies in five apiaries close to corn grown from neonicotinoid-treated seeds and a further six apiaries situated far from agricultural fields.
Both were extensively sampled and tested for pesticides during the entire active Canadian bee-keeping season from early May to September 2016.
"One of the really surprising things we found is that honeybees were exposed to neonicotinoids on average for three months, which is previously unreported," York PhD student Nadia Tsvetkov told Reuters.
"Before we 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. Honeybees rarely collected pollen from corn or soy, which are the target plants. Often the pollen came from things like willow and clover."
The findings indicate that neonicotinoids, which are water soluble, spill over from agricultural fields into the surrounding environment, where they are taken up by other plants attractive to bees.
"This indicates that neonicotinoids are slipping into the system and persisting there throughout the year. We also found was that neonicotinoids were present in honeybee colonies before corn was planted, so probably from the previous year's planting," said Tsvetkov.
Researchers later fed colonies with an artificial pollen supplement containing progressively smaller amounts of the most commonly used neonicotinoid in Ontario, clothianidin, over 12 weeks, mimicking what would occur naturally.
Worker bees exposed during the first nine days of life died on average 23 per cent earlier. Exposed colonies were unable to maintain a healthy laying queen and suffered poor hygiene.
Researchers also found that a commonly used fungicide, Boscalid, interacted with neonicotinoids to increase the ill-effects.
"On their own the fungicide did not kill bees but when we combined it with the neonicotinoid the mixture was twice as toxic as the neonicotinoid alone," said Tsvetkov.
The study was published in June in the journal Science.
"Even though the health effects we found were mild, because the neonicotinoids persist in the system for so long the health effect really accumulates," said Tsvetkov.
Academic peers backed the findings. Dave Goulson, Professor of Biology at the University of Sussex, told the New Scientist: "Whatever you use the chemicals on, they are contaminating the environment and getting into bees' food. I think you'd have to be pretty unreasonable at this point not to accept that, at least some of the time, these chemicals harm bees when used in normal farming practice."
Four years ago the European Union introduced a temporary moratorium on the use of three major neonicotinoids on bee-attractive crops. Draft regulations form the European Commission are expected to extend the ban and make it permanent.
Bees are the world's most important pollinator. Estimates suggest that a third of the food we consume relies on pollination, primarily by bees. - Copyright Holder: FILE REUTERS (CAN SELL)
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