An extended pesticide ban is vital to our bee population

There is growing experimental evidence that neonicotinoids harm pollinators, but little monitoring of wild populations. Citizen science can help fill the gap, says Dave Goulson.

In spring 2012, my postdoc Penelope Whitehorn and I published a paper in Science on the effects of neonicotinoid pesticides on bumblebee colonies. It appeared to show that doses of these chemicals, of the amount that bees would encounter if they fed on a treated oilseed rape crop, caused greatly reduced colony growth and an 85 per cent drop in production of new queens. The work appeared alongside another paper from a French group showing that the same chemicals impaired honeybee navigation, possibly leading to colony collapse if too many worker bees became lost.

These chemicals are the world’s most widely used insecticides, and these studies, which built on previous work, suggested that they had got through the regulatory process without proper evaluation of the threat they posed to bees. The European Union asked the European Food Safety Authority to conduct a review of their safety, and in January 2013 Efsa announced that neonicotinoids posed “an unacceptable risk” to bees.