Neonicotinoids and bees: What's all the buzz?

Neonicotinoid insecticides kill bees. Or do they? The European Union has approved a moratorium – though manufacturers say there is no evidence to implicate their product. But they demand experiments that cannot be performed, says Dave Goulson, subject their own data to no statistical analysis, and spuriously reject good evidence that does exist. So how strong is the link between these chemicals and the decline of our bees?