Glossary
A second-generation neonicotinoid insecticide widely used in agriculture as a seed treatment and foliar spray. Thiamethoxam is converted to clothianidin in both plants and insects, and has been documented to impair honey bee navigation, foraging efficiency, and colony reproduction even at sublethal field-relevant concentrations.
Thiamethoxam is one of three neonicotinoids (alongside imidacloprid and clothianidin) restricted by the European Union since 2018 due to demonstrated risks to pollinators. Research has shown that field-relevant exposure levels impair bee navigation (foragers cannot find their way home), reduce foraging rates, suppress queen egg-laying, and increase colony susceptibility to diseases and parasites.
A landmark 2012 study published in Science demonstrated that honey bees exposed to thiamethoxam at concentrations found in treated crop nectar experienced a 2-3 fold increase in failing to return to the hive, effectively depleting the colony's foraging workforce.
Register your apiary with state agricultural agencies to receive pesticide application notifications. Communicate with neighboring farmers about your hive locations. If possible, position hives away from fields treated with neonicotinoid-coated seeds (corn, soybean, canola, sunflower).
Maintaining strong, well-nourished colonies improves resilience to pesticide stress. Colonies with diverse forage sources are less vulnerable because they are not dependent on a single treated crop. Supporting pollinator-friendly farming practices in your community creates systemic change.
The EU restricted outdoor use of thiamethoxam in 2018. In the United States, it remains registered for use but with increased label restrictions for pollinator protection. Several states have proposed additional restrictions. The regulatory landscape is evolving.
Primarily through nectar and pollen from treated crops. Thiamethoxam is systemic, meaning it is absorbed by the plant and distributed throughout all tissues including flowers. Seed treatments applied at planting result in residues in pollen and nectar months later when the crop blooms.
Yes. Laboratory testing services can analyze bee bread (stored pollen) and wax samples for neonicotinoid residues. This can help identify if your colonies are experiencing pesticide exposure from neighboring agricultural operations.
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