Harvard study links pesticides to bee deaths

Colony Collapse Disorder (CCD) in honeybees (Apis mellifera) can be linked with low-dose insecticides. Philip Case at the UK magazine Farmers Weekly tells us about research in the States, where CCD is a huge problem. This is a serious matter for all of us because without bees, we’d go hungry.

Here’s the press release from the Harvard School of Public Health. Here’s the research paper.

A team of scientists led by Dr Chensheng (Alex) Lu fed bees low doses of two neonicotinoids in sugar-water. Then they let the bees return to foraging from their hives. The sugar-water contained two of the neonics which, since last December, are under a temporary ban here in Europe. The insecticides these scientists used were imidacloprid and clothianidin, both made by the chemical and biotech giant Bayer.

So much for the pro-neonic view dissing the science that underlies the European neonic ban. Another chemical and biotech giant, Syngenta, who make another neonic called thiamethoxam now banned in Europe, isn’t impressed by that science. Syngenta accused that science of using high doses of neonics, that bees wouldn’t face on real farmland.

But this new research used low doses, and the bees still died. In fact, it wasn’t the first time this had been shown. Good science has to be repeatable and yes, this science has now been repeated.

The scientists who did the new research also found a bee parasite called Nosema ceranae causing CCD in one of the hives they’d kept neonic-free. So CCD isn’t all about neonics. But, this new research says, Bayer’s neonics really do not help bees.

[Edit] Here’s another article about the new research. Damian Carrington at the Guardian points out a key finding: the bees exposed to low-dose imidacloprid and clothianidin didn’t behave normally. They abandoned their hives in winter, then died of cold. The few bees which had become infested by the common parasite N. ceranae behaved normally for winter, staying in their hives. Dr Lu and his team say that this is one of their most remarkable findings. They found no evidence of neonics making bees more vulnerable to parasites. Instead, they found neonics making bees behave weirdly.

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