Neonicotinoid Insecticides (Imidacloprid, Clothianidin, Thiamethoxam)

Neonicotinoid insecticides — most notably imidacloprid, clothianidin, and thiamethoxam — are widely used as seed coatings and sprays and have been strongly linked to honey-bee colony collapse disorder, causing disorientation and mass die-offs sometimes described as "mad bee disease." The European Union banned outdoor use of the three core neonicotinoids in 2013 and expanded the ban in 2018; as of 2026 the EU has moved to prohibit imports of products containing even trace amounts of the banned chemicals. Enforcement has been contested: pesticide manufacturers and growers have used emergency-use exemptions extensively, with more than 200 granted across the EU in 2023 alone, nearly half involving neonicotinoids. The chemicals remain broadly legal and widely used in the United States.