Though relatively new on the market, neonicotinoids are the most-used class of insecticides on earth. For example, one chemical in this class, Clothianidin, is used in the production of the vast majority of corn grown in the United States. Neonicotinoids are also commonly found in many household garden chemical products and greenhouse-grown ornamental plants that are pre-treated prior to sale in nurseries. Some nurseries in the U.S. are refusing to sell plants pre-treated with neonicotinoids, but most nurseries have not followed suit.
Scientific evidence has been mounting from a range of studies that neonicotinoids are particularly damaging to bees. Neonicotinoids not only kill bees, they can also affect them in other ways. Even at low concentrations, sometimes measured in a few parts per billion, neonicotinoids can impair bee immune systems, learning, foraging, and navigation.