Research & References
How do neonicotinoids harm bees & other wildlife?
Neonicotinoids are likely to weaken already vulnerable populations – the final straw on top of the other threats that bees and other farmland wildlife face.
How plants become contaminated
Scientists have found that systemic pesticides such as neonicotinoids, which spread into every part of the plant, are contaminating to our countryside. Only 5% of neonicotinoid seed treatments remain in the crop, 1% is lost as dust, 94% goes into soils and streams . Any growing plant can take these chemicals up into their leaves, stems, flowers and fruits and scientists have now found neonicotinoids at high doses inside the pollen of wildflowers, such as poppies and hedgerow blossom .
Impact on honeybees
Research has focussed on the impact of these insecticides on honey bees. The chemicals have been found to impair bees’ communication, homing and foraging ability, flight activity, ability to discriminate by smell, learning, and immune systems. These all have an impact on bees' ability to survive.
Impact on other wildlife
According to the findings of the Worldwide Integrated Assessment on Systemic Pesticides 'Neonicotinoids impact all species that chew a plant, sip its sap, drink its nectar, eat its pollen or fruit'. This is because neonicotinoids act systemically. Plants, including wildflowers and hedgerows growing near treated crops, take these insecticides up into their leaves, stems, roots, flowers, pollen and nectar.
Whilst the impact of neonicotinoids on other wildlife has been poorly studied, as new research on other species is carried out, it is raising worrying questions about the wider impacts of neonicotinoids on our farmland wildlife.
- Wild bees: Field trials suggest that wild bees may be more vulnerable to neonicotinoids than honey bees. There are nearly 2000 species of wild bees in Europe and nearly 1 in 10 are declining so severely they face extinction .
- Butterflies & other pollinators: Once common and widespread UK farmland butterflies have declined by more than half since 2000, despite conservation spending doubling. Neonicotinoid usage has been found to strongly correlate with these declines . In total wild pollinators provide us with up to 60-90% of our insect pollination .
- Leaf eaters: Research in the USA found that Monarch butterfly caterpillars are harmed when eating the leaves of wildflowers growing near to neonicotinoid treated crops . But the impact of contaminated wild plant leaves on caterpillars, beetles and other leaf eaters has been poorly studied.
- Birds: According to leading bee researcher Professor Dave Goulson in a session at the Soil Association Conference 2014; 'Five neonicotinoid dressed maize seeds, or 32 dressed oilseed rape seeds, are enough to kill a partridge', though more research is needed . Evidence also suggests birds are being indirectly effected through their food supply (see below).
- Aquatic wildlife: Widespread contamination of waterways has been already discovered in some countries . Similar levels may be seen here in the UK, but no research has yet been done. Aquatic invertebrates, such as mayflies and water fleas, can suffer harm from low doses of neonicotinoids and concern is mounting for the safety of aquatic ecosystems [9,12].
- Soil life: Research has found neonicotinoids in 100% of soil samples from treated crops, and nearby hedgerows. Whilst there has been little research into the impact of this, some research on common species of earthworms suggests that the levels found could cause both harm .
- Indirect effects due to a decline in insect food: Much of our farmland wildlife needs a diet rich in insects and other bugs to survive. Intensive farming has already caused a decline in this food source, and neonicotinoids may be making this scarcity even worse. In the Netherlands, strong correlations were found between neonicotinoid contamination of waterways and bird declines – this link could be caused by the decline in insects and the impact of this on birds’ diets and ability to feed their chicks .
A pesticide cocktail in our countryside
Previous research from the USA and France suggests that wildflower pollen can contain a complex cocktail of contaminating pesticides – with completely unknown effects on pollinators. Research by Sussex University and supported by the Soil Association further highlighted the impact of neonicotinoids. Here’s what they found:
- UK bees are exposed to whole cocktail of pesticides – the overall impact of these cocktails remains completely unknown and untested.
- Samples of pollen from bumblebee and honeybee nests contained on average between 5 and 7 different pesticides, mostly from wildflowers.
- In the pollen of the wildflowers sampled by neonicotinoid treated crops, an average of 3-4 pesticides were found
- Contaminated plant species included Creeping Buttercup, White Campion, Scented Mayweed, Hogweed, Poppy, Wild Rose, Burnet Saxifrage and Fool's Parsley.
- The impact of the controversial insecticides, neonicotinoids, may be being underestimated. 100% of pollen samples collected by bees contained mixtures of neonicotinoids and fungicides, which previous research shows may increase the toxicity of neonicotinoids by up to 1000 times.
- The research shows that the current partial ban on neonicotinoids must be extended to cereals as neonicotinoid cocktails were found in the pollen of wildflowers near to treated wheat.
Read our press release, with links to the peer-reviewed paper here
-  Goulson (2015) ‘The Environmental Fate of Neonicotinoids’ http://www.nature.com/nature/journal/v511/n7509/fig_tab/nature13642_F1.html
-  Botias et al (2015) ‘Neonicotinoid Residues in Wildflowers, a Potential Route of Chronic Exposure for Bees’
-  http://ec.europa.eu/environment/nature/conservation/species/redlist/downloads/European_bees.pdf
-  Gilburn, A. S., Bunnefeld, N., Wilson, J. M., Botham, M. S., Brereton, T. M., Fox, R., & Goulson, D. (2015). Are neonicotinoid insecticides driving declines of widespread butterflies? PeerJ, 3, e1402. http://doi.org/10.7717/peerj.1402
-  http://planetearth.nerc.ac.uk/news/story.aspx
-  Pecenka, J. R., & Lundgren, J. G. (2015). Non-target effects of clothianidin on monarch butterflies. The Science of Nature, 102(3-4), 19. http://doi.org/10.1007/s00114-015-1270-y
-  Gibbons, D., Morrissey, C., & Mineau, P. (2015). A review of the direct and indirect effects of neonicotinoids and fipronil on vertebrate wildlife. Environmental Science and Pollution Research International, 22(1), 103–18. http://doi.org/10.1007/s11356-014-3180-5
- [8,11] Hallmann, C. A., Foppen, R. P. B., van Turnhout, C. A. M., de Kroon, H., & Jongejans, E. (2014). Declines in insectivorous birds are associated with high neonicotinoid concentrations. Nature, 511(7509), 341–3. http://doi.org/10.1038/nature13531
- [9,10] Pisa, L. W., Amaral-Rogers, V., Belzunces, L. P., Bonmatin, J. M., Downs, C. A., Goulson, D., … Wiemers, M. (2015). Effects of neonicotinoids and fipronil on non-target invertebrates. Environmental Science and Pollution Research International, 22(1), 68–102. http://doi.org/10.1007/s11356-014-3471-x
-  Hallmann, C. A., Foppen, R. P. B., Van Turnhout, C. A. M., De Kroon, H., & Jongejans, E. (2014). Declines in insectivorous birds are associated with high neonicotinoid concentrations. Nature, 511. https://doi.org/10.1038/nature13531
-  Sánchez-Bayo, F., Goka, K., & Hayasaka, D. (2016). Contamination of the Aquatic Environment with Neonicotinoids and its Implication for Ecosystems. Frontiers in Environmental Science, 4, 71. https://doi.org/10.3389/fenvs.2016.00071
- Neonics infographic
- The Soil Association submitted evidence to the UK Environmental Audit Committee's inquiry into Insects and Insecticides in November 2012. The submission provides as useful a summary of the evidence against neonicotinoids as it did then. Read here
- Our full position on neonicotinoids
- Pesticide Action Network UK’s bee and pesticide fact sheets
- Myths and Truths about Neonics
Last edited: 6th June 2017