Glossary
The first commercially developed neonicotinoid insecticide and the most widely used insecticide in the world. Imidacloprid acts on the nicotinic acetylcholine receptors of insects, causing paralysis and death. It is systemic, meaning it is absorbed by plants and distributed throughout all tissues including pollen and nectar, creating exposure pathways for pollinators.
Imidacloprid has been one of the most intensively studied pesticides regarding pollinator harm. Documented sublethal effects include impaired navigation (bees cannot find their way home), reduced learning ability, suppressed immune function, decreased brood production, and increased susceptibility to diseases and parasites, all at field-relevant concentrations.
A pivotal 2012 study in Science by Henry et al. demonstrated that sublethal exposure to imidacloprid caused a 2-3 fold increase in homing failure rates in foraging honey bees. This loss of foragers, compounded over weeks and months, can weaken colonies to the point of collapse.
The European Union banned outdoor use of imidacloprid (and two other neonicotinoids) in 2018 based on risk assessments by the European Food Safety Authority. In the United States, imidacloprid remains registered for use but with increased pollinator protection labeling requirements added in 2016.
The ongoing scientific, regulatory, and economic debate about neonicotinoids centers on balancing agricultural pest management with pollinator protection. Alternative pest management strategies including integrated pest management, targeted application methods, and alternative insecticides continue to be developed.
No. Imidacloprid remains registered for use in the United States. However, the EPA has added pollinator protection language to labels, restricting application during bloom when bees are actively foraging. Several states and municipalities have enacted additional local restrictions.
Through contaminated pollen and nectar from treated plants (the primary route), dust generated during planting of treated seeds, contaminated water in puddles and guttation droplets, and soil residues from previous applications. Imidacloprid can persist in soil for years.
Register apiaries with state agriculture agencies to receive spray notifications, communicate with local farmers about hive locations, maintain strong colonies to improve resilience, provide diverse forage to reduce dependence on treated crops, and support policy changes through beekeeping associations.
Keep Learning
Browse hundreds of terms covering honey, beekeeping, and natural skincare.