With European wildlife and agriculture suffering from a sharp decline in pollinator insects, the European Union implemented a partial ban on three neonicotinoids—imidacloprid, clothianidin, and thiamethoxam—in 2013, restricting their use on crops attractive to bees. This ban was extended in 2018 to include all outdoor uses. The UK, then a member of the EU, adopted these regulations and elected to uphold them post-Brexit – that is, until 2022, when the Conservative government authorised the use of thiamethoxam, a neonicotinoid, on sugar beet crop as a means of treating certain viruses, with about 70% of the national sugar beet crop could be affected. To limit harm to pollinators, farmers using thiamethoxam were prohibited from growing flowering plants for 32 months after. However, the side-effect is that this prohibition, necessary to stop the pesticide harming pollinators, will mean less pollen for bees and other pollinators to consume, risking further declines in their number. Prior to this authorisation, though, the bans on neonicotinoids have shown positive outcomes for pollinator populations in the UK. For example, there has been a noted rise in 12% of wild bee species that are key pollinators for crops. This recovery is attributed to both the reduced use of neonicotinoids and efforts by farmers to create pollinator-friendly habitats, such as planting wildflowers along field borders. 

What are neonicotinoids – and how do they harm pollinators? 

Neonicotinoids are a group of insecticides chemically similar to nicotine. They work by affecting the central nervous system of insects, leading to paralysis and death. Neonicotinoids are systemic, meaning they are absorbed by plants and can be present in all parts, including nectar and pollen, making them particularly harmful to pollinators. 

In the UK, neonicotinoids have been used extensively since the 1990s to protect a variety of crops, including oilseed rape, sugar beet, and various fruits and vegetables. Their popularity stems from their effectiveness in controlling pests and their relatively low toxicity to humans and other mammals. However, their widespread use has raised significant environmental concerns. 

Neonicotinoids are highly toxic to bees and other pollinators. Even at sub-lethal levels, these chemicals can impair foraging behavior, navigation, learning, and reproduction in bees. Exposure to neonicotinoid-treated crops can reduce colony growth and increase mortality rates. For instance, studies have shown that bees exposed to neonicotinoids exhibit reduced ability to forage and return to the hive, leading to weakened colonies and increased vulnerability to other stressors . 

Neonicotinoids also have indirect effects on pollinators. By contaminating soil, water, and non-target plants, these chemicals create a hostile environment for pollinators. The decline in wildflowers and other plants essential for pollinator nutrition exacerbates the problem, leading to reduced food availability and habitat loss . 

Research in the UK has highlighted the severe impact of neonicotinoids on pollinator populations. A comprehensive study by the Centre for Ecology and Hydrology in 2019 analyzed over 715,000 records from volunteer nature observers and found that the geographic range of bees in the UK declined by approximately 25% between 1980 and 2013. Additionally, a significant decline in bee species associated with uplands, where neonicotinoid use is prevalent, was observed, with a 55% reduction in these populations. 

What do the Greens propose?  

Well, it’s quite simple, really – here's the quote from their manifesto: 

The Act would also set standards for soil quality and phasing out the most harmful pesticides immediately (including glyphosate) and, as we move towards regenerative farming methods, introduce rigorous tests for all pesticides. Only pesticides that pass this test, and demonstrably don’t harm bees, butterflies and other wildlife, would be approved for use in UK and we would end the emergency authorisation of bee-killing pesticides. 

This is a far more important proposal than simply returning to yesterday’s status quo. The ban on neonicotinoids alone had led to increased use of alternative pesticides, some of which may also pose risks to pollinators. Additionally, illegal use and contamination of the environment with residual neonicotinoids continue to threaten pollinator health. Continuous monitoring and research are essential to fully understand and mitigate these risks – which is why the Greens’ commitment to ‘developing a soil health monitoring programme for England [...] to assess and understand changes in the health of soil over time’ is welcome, too.  

Similarly, adopting sustainable farming practices is crucial for the long-term protection of pollinators. Integrated Pest Management (IPM) strategies, which combine biological, cultural, and mechanical control methods, can reduce reliance on chemical pesticides. Promoting organic farming and encouraging biodiversity on farms through the planting of wildflowers and maintaining natural habitats can also support pollinator populations. 

Ongoing research into the effects of neonicotinoids and other pesticides on pollinators is essential. Developing and implementing safer, targeted pest control methods can help protect pollinators while maintaining agricultural productivity. Innovations in pesticide formulation, application techniques, and pest-resistant crop varieties offer promising avenues for reducing environmental impact. 

Neonicotinoids have played a significant role in the decline of pollinator species in the UK, with dire consequences for both natural ecosystems and agriculture. While regulatory measures have led to some recovery, ongoing challenges necessitate a shift towards more sustainable farming practices and continued research into safer alternatives. With the Greens in for a historic election, potentially quadrupling their Commons representation (though, admittedly, that would only mean 4 Green MPs...), we’re likely to see a widening of the debate around agriculture and the protection of wild ecosystems, in which pesticides will continue to feature heavily.