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Bees Survival: Ban More Pesticides?

07 May 2013

EU - Neonicotinoids are currently under intense scrutiny. But a ban of a broad variety of pesticides may be required to protect bees, humans and the environment.

Scientists are now warning that other nerve agents targeting insect pests may also be harming bees and other pollinators.

“These neonicotinoids are just one of hundreds of compounds being used and I would be surprised if it was all down to just these chemicals,” says Christopher Connolly, a neuroscientist at the University of Dundee, UK. He argues that we should not allow farmers spray a toxic soup of chemicals onto their crops.

Pesticides 'not adequately tested'

Connolly exposed bee brains to these pesticides and organo-based pesticides andreported that the nerves spun into hyperactivity and then stopped working. A combination of these two pesticides types had a stronger impact, suggesting the combined soup of pesticides could be causing more serious harm.

“I don’t understand how this was missed. As a neuroscientist it just seemed blindingly obvious. The biggest effect was hyperactivation of the major learning centre, which was completely predictable,” Connolly tells

The nerve agents effects were missed because safety screens looked to see how many honey bees die after four days exposure. But harm is only evident over a period of two weeks in bumblebees and is seen when you look at entire colonies.

More research needed

Connolly argues that we need to carry out research to find out which pesticides are the least harmful. If neonicotinoids are the least toxic, then we should go with them. He says governments have underfunded this research area partly because it is inconvenient to find pesticides are dangerous.

Dave Goulson, professor of biological science at the University of Sterling, UK agrees: “there haven’t been nearly enough studies of all pesticides or interactions between them.”

He recently published a studyshowing neonicotinoids hit bumblebee colony growth and queen production. He also tells “Beneficial insects such as ladybirds and bees are exposed to lots of different chemicals and we have a really poor understanding of what it does to them.” He also points out that we need to be concerned with what we replace these nerve agents with.

Further Reading

You can view the full report by clicking here.

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