Bees and other pollinators (including native bees, butterflies, moths, flies, and beetles) are essential for pollinating about 75–90% of flowering plants and roughly one-third of global food crops by volume. Their decline threatens food security, biodiversity, and ecosystems.

Observed Declines in Bees and Pollinators

Honey bee colony losses have been significant in parts of North America and Europe, especially during the mid-2000s peak of Colony Collapse Disorder (CCD). Managed U.S. honey bee colonies dropped notably from the late 1980s to around 2007–2009 before partially stabilizing or recovering in some years due to beekeeper interventions (though overwintering losses remain high, often 30–50% in bad years). Wild/native pollinator populations show clearer long-term declines in diversity and abundance in many regions.

Declines are multifactorial:

• Parasites and diseases (e.g., Varroa mites and associated viruses — often cited as a top stressor for managed hives).
• Habitat loss and reduced forage (monocultures, urbanization). Lack of native vegetation.
• Climate change and poor nutrition.
• Environmental chemicals, particularly pesticides and related chemical applications to the soil.

The Link to Environmental Chemicals

The strongest and most studied connection involves pesticides, especially a class of systemic insecticides called neonicotinoids (neonics: imidacloprid, clothianidin, thiamethoxam, etc.). These are widely used as seed coatings, soil treatments, and sprays on crops like corn, soy, cotton, and many others.

How neonics work and harm pollinators:

• They are systemic: absorbed by the plant and distributed throughout tissues, including nectar and pollen.
  
  
• Bees ingest or contact residues while foraging.
  
  
• They target insect nicotinic acetylcholine receptors, disrupting the nervous system.

Effects on bees:

• Acute/lethal: High doses kill bees directly (highly toxic by contact and ingestion).
  
  
• Sublethal (often more concerning at field-realistic levels): Impaired navigation, learning, memory, foraging efficiency, communication, and homing. Reduced immune function, making bees more susceptible to diseases/parasites. Lower reproduction and colony growth. Effects can persist due to environmental persistence in soil and water.

Hundreds of peer-reviewed studies, lab and field research (including some industry-funded), and assessments link neonics to pollinator harm. The European Union restricted/banned outdoor uses of several major neonics starting in 2018 due to risks. In the U.S., the EPA has conducted extensive risk assessments, added pollinator warnings to labels, restricted certain uses (e.g., during bloom), and proposed further mitigations like reduced applications on blooming crops.

Other chemicals also play roles:

• Glyphosate (active ingredient in Roundup and similar herbicides): Meta-analyses and studies show it can increase bee mortality at relevant doses, disrupt gut microbiomes (increasing disease susceptibility), impair learning/memory/foraging, delay brood development, and harm bumblebee colony thermoregulation (critical for brood survival). Effects are mostly sublethal.
  
  
• Fungicides and older insecticides (e.g., organophosphates, pyrethroids) can be directly toxic or act synergistically with neonics/insecticides to increase overall harm.
  
  
• Broader pollutants (e.g., heavy metals or emerging contaminants) have less studied but potential indirect effects.

Pesticides do not act in isolation — they often interact with other stressors (e.g., a neonic-exposed bee is weaker against Varroa or poor nutrition). Not every pesticide use harms bees equally; timing, application method (e.g., seed treatments vs. sprays), and alternatives matter. Some uses (like certain neonics for citrus greening) have strong agricultural benefits with debated net pollinator trade-offs.

Spotlight on Glyphosate

Impact of Glyphosate on Pollinators

Glyphosate and Bee Health

Glyphosate, a widely used herbicide, can influence the health of pollinators, particularly bees. Research indicates that glyphosate exposure alters the gut microbiomes of bees, which may have indirect effects on their overall health and ability to resist parasites.

Effects on Gut Microbiome

• Microbial Composition Changes: Glyphosate exposure can shift the composition of gut bacteria in bees. This shift tends to favor species that are tolerant to glyphosate while disfavoring sensitive species.
  
  
• Health Implications: Changes in the gut microbiome can affect bees' immune systems and their resistance to pathogens, potentially leading to increased vulnerability to diseases.

Broader Implications for Pollinators

• Pesticide Exposure: Pollinators are often exposed to multiple pesticides, including glyphosate, which can compound the negative effects on their health. More than 90% of pollen samples from bee hives in agricultural areas are contaminated with various pesticides.
  
  
• Ecosystem Role: Bees play a crucial role in ecosystems by pollinating plants, which is vital for food production and biodiversity. Disruptions to their health due to glyphosate could have significant ecological consequences.

In summary, there is a clear link between glyphosate and pollinator health, primarily through its impact on the gut microbiome of bees. This relationship highlights the need for careful management of herbicide use to protect these essential insects.

Regulatory and Scientific Context

• EPA (U.S.): Ongoing registration reviews for neonics with pollinator-focused risk assessments, label improvements, and best management practices. No full ban on major neonics as of 2026, but restrictions and stewardship efforts exist. They emphasize science-based risk-benefit analysis under pesticide laws.
  
  
• Broader assessments (e.g., IPBES pollinators report) identify pesticides as a major driver of pollinator decline alongside habitat issues.
  
  
• Many scientists and environmental groups argue current regulations underestimate sublethal and chronic effects or synergistic risks.

Bottom Line

The link is real and well-documented: certain environmental chemicals — especially neonicotinoid insecticides and to a lesser extent herbicides like glyphosate — expose bees and pollinators through residues in pollen, nectar, dust, soil, and water. This contributes to direct mortality, weakened colonies, and reduced resilience to other threats.

Managed honey bee numbers have shown some resilience in places, but overall pollinator health and biodiversity remain under pressure. Reducing unnecessary or high-risk pesticide use, adopting integrated pest management (IPM), planting pollinator-friendly habitats, and supporting research into safer alternatives are key steps supported across stakeholders.

Well Water Users - Comprehensive Water Testing including Pesticides and Herbicides.   If you are only concerned with Glyphosate in your water or irrigation water. 

Understand What’s in Your Soil

Pesticides and herbicides don’t just affect pollinators — they persist in soil and can leach into groundwater. If you’re concerned about chemical contamination in your environment, our Soil Guide provides practical, science-based guidance on understanding soil health, chemical interactions, and what you can do to protect your land and water. Get your copy today →

References

U.S. Environmental Protection Agency. (2026, March 11). EPA actions to protect pollinators. https://www.epa.gov/pollinator-protection/epa-actions-protect-pollinators

Natural Resources Defense Council. (2025, June 11). Neonicotinoids 101: The effects on humans and bees. https://www.nrdc.org/stories/neonicotinoids-101-effects-humans-and-bees

Fairbrother, A., Purdy, J., Anderson, T., & Fell, R. (2015). Risks of neonicotinoid insecticides to honeybees. Environmental Toxicology and Chemistry, 34(4), 719–728. https://doi.org/10.1002/etc.2858

IPBES. (2016). The assessment report on pollinators, pollination and food production. Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. https://www.ipbes.net/assessment-reports/pollinators

United States Department of Agriculture, National Agricultural Statistics Service. (Various years). Honey bee colonies reports. https://www.nass.usda.gov/Surveys/Guide_to_NASS_Surveys/Bee_and_Honey/