Bee killers – Neonicotinoid pesticides in New Zealand

Biodiversity rhetoric often excludes comment on contamination and pollution from economic activity. Narratives relating to biodiversity loss often exclude the relationship of biodiversity decline and persistent applications of pesticides over years. Also avoided are the low level, or sub-chronic exposures to surrounding ecosystems -the soil and water profiles, and the terrestrial and aquatic creatures that live in these environments or pass through them.

This incapacity to judge to cumulative exposures, and the cascading effects of exposures for juvenile organisms, is a driver of biodiversity decline. Regulatory authorities have demonstrated a persistent unwillingness to adopt new forms of science at high level – to incorporate biomarker exposures and neurodevelopmental effects, and take account of the second and third order harms that directly effect the resilience and robustness of a species. These issues remain left off the regulatory risk assessment table and not included in policy and regulations.

Regulatory agencies directly and indirectly contribute to biodiversity decline when they identify gaps but do not publicly advocate or develop channels to ensure that this scientific work is undertaken in the public sector (as independently produced science. Much of this science remains undone because it represents uncomfortable knowledge.

Neonicotinoid contamination is a touchstone – an example of the failure to appropriately regulate technologies, including pesticides. Neonicotinoid insecticides widely contaminate ecosystems, including flora and fauna, as well as humans. Neonicotinoid insecticides are persistent, bioaccumulative and toxic.

Neonicotinoids are a problem

  1. Neonicotinoids can persist for years in soils and environmental concentrations may accumulate, negatively impacting beneficial soil invertebrates. Neonicotinoid insecticides are highly mobile, and travel into into surface and groundwater.
  2. Neonicotinoids are not confined to a treated seed. Dust created (from drilling of neonicotinoid treated seeds) is lethal to flying insects and has caused large-scale acute losses of honeybee colonies. Foliar spray drift can harm non-target insects. Local non-crop plants, eg. field margins, hedgerows and near contaminated waterways have been contaminated with neonicotinoids.
  3. Neonicotinoids and fipronil have been found in nectar, pollen, and exuded guttation drops (which bees drink) of treated crops and locally growing untreated wildflowers. There is evidence bees and their colonies are directly affected and harmed by these exposures.
  4. Birds and mammals that eat the treated seeds may be killed or harmed (immune system damage, reduced fecundity, lethargy) at low doses.
  5. Best practice farming utilises ‘Integrated Pest Management (IPM)’. The basis of IPM is that pesticides (including neonicotinoids) are only used when necessary. Yet farmers routinely use treated seeds, which is directly against IPM protocols. A large amount of neonicotinoid use is ‘prophylactic’  – habitual use of seed dressings whether there is an insect threat or not. This can lead to resistance in insect populations and may provide no real benefit, while exposing the surrounding environment to harm.

Deficient monitoring & regulation cannot protect BIODIVERSITY

  • There is no cumulative testing for the different mixtures of fungicides/herbicides/insecticides that pollinators are commonly exposed to.
  • ‘Subtle’ problems such as navigational impairment are not considered
  • Queen health and fertility (especially intergenerational) is ignored
  • Cumulative low level environmentally relevant exposures are dismissed
  • Only the active ingredient is assessed – yet a seed coating or treatment will contain other ingredients that act as synergists and make the neonicotinoid more toxic to bees.
  • Neurotoxic effects may result in behaviour changes that reduce the ability for insect colonies to thrive; and may adversely harm predator/prey relationships.
  • Non-target species are threatened by secondary poisoning: Eg. Insect eating birds are vulnerable to neonicotinoid insecticides that persist in local environments.

Neonicotinoid regulation in New Zealand

Link to Rumble video

Neonicotinoids are in New Zealand soil and water. New Zealand monitoring and analysis of anthropogenic chemicals in the environment is poor. New Zealand lacks an institution with flexible long term (block) funding to test for, monitor and analyse and research pesticides in the environment. The only long-term monitoring undertaken, National survey of pesticides and emerging organic contaminants (EOCs) in groundwater, does not detect for neonicotinoid insecticides. So while scientists have demonstrated interest in the environment, lacking a dedicated institution, our science resembles a scatterplot and cannot build an evidence-base for regulation. Science is further hindered by the absence of regulatory feedback, New Zealand regulators do not transparently feed back into the science environment, nor is there policy and funding to require such a feedback loop. Such science could then science be funded to independently fill in the data gaps left open when industry submissions fail to include the data (and it is not a condition of authorisation by the regulator).


Benbrook et al 2021. Commentary: Novel strategies and new tools to curtail the health effects of pesticides. Environmental Health 20:87 10.1186/s12940-021-00773-4

Close & Humphries 2019. National Survey of Pesticides and Emerging Organic Contaminants (EOCs) in Groundwater 2018. CSC19016 Institute of Environmental Science and Research Limited

DiBartolomeis, M., Kegley, S., Radford, R., & Klein, K. (2019). Research Article. An assessment of acute
insecticide toxicity loading (AITL) of chemical pesticides used on agricultural land in the United States. PLoS ONE, 14(8), e0220029.

Goulson D. (2021(. Silent Earth. Penguin Books

Hageman et al 2019. Current- Use Pesticides in New Zealand Streams: Comparing Results from Grab Samples and Three Types of Passive Samplers. Environmental Pollution, 254, 112973.

Laubscher, B. et al. (2022). Multiple neonicotinoids in children’s cerebro-spinal fluid, plasma, and urine. Environmental Health, 21, 10,

Maarten Bijleveld van Lexmond & Jean-Marc Bonmatin & Dave Goulson & Dominique A. Noome (2015) Worldwide integrated assessment on systemic pesticides Global collapse of the entomofauna: exploring the role of systemic insecticides. Environ Sci Pollut Res (2015) 22:1–4. Worldwide integrated assessment

Mesnage R, Bernay B, Séralini GE (2013) Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity. Toxicology, 313, 2-3 122-8.

Parliamentary Commissioner for the Environment 2020. A review of the funding and prioritisation of environmental research in New Zealand

Pook & Gritcan 2019 Validation and application of a modified QuEChERS method for extracting neonicotinoid residues from New Zealand maize field soil reveals their persistence at nominally hazardous concentrations. Environmental Pollution. 255:1;113075

Sánchez-Bayo, F., & Wyckhuys, K. (2019). Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation, 232, 8-27.

Tsvetkov et al. (2017). Chronic exposure to neonicotinoids reduces honey bee health near corn crops Science 356, 6345, 1395-1397.

Wood, T.J. & Goulson, D. (2017). The environmental risks of neonicotinoid pesticides: a review of the evidence post 2013 Environ Sci Pollut Res, 24, 17285–17325.

Woodcock et al. (2017).Country-specific effects of neonicotinoid pesticides on honey bees and wild bees. Science 356, 6345,1393-1395.

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