Large study links key pesticide to weakened honeybee hives

By SETH BORENSTEIN Markets Associated Press

A massive new study in three European countries finds a common pesticide dramatically weakens already vulnerable honeybee hives.

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For their experiment, researchers planted fields of rapeseed, which is made into cooking oil. Some of the fields were planted with seeds treated with the class of insecticides called neonicotinoids, others with untreated seeds. The researchers followed bees from the spring of 2015 when the seeds flowered to the following spring when new bees were born.

In Hungary and Britain, the hives that had bees foraging around insecticide-treated plants had a more difficult time surviving the winter. In Germany, where the bees are generally healthier, there was no noticeable harm to the bees from the insecticide.

The study is in Thursday's journal Science.