Is America's most common pesticide responsible for killing our bees?

A growing body of studies shows that neonics threaten the health of honey bees, but some argue there's not enough evidence to justify an outright ban

The most widely used class of insecticides in the world is facing a slow death. Called neonicotinoids, or neonics, these bug killers have long been used to coat seeds or treat millions of acres of farmland in the US. Research showing that they sicken or kill bees and other pollinators has already prompted the European Union to temporary ban several varieties of the insecticides, and now neonics could lose their grip in North America, too.

Related: Bee's knees: a new $4m effort aims to stop the death spiral of honeybees