Bees, pesticides and neonicotinoids
Since 1900, we’ve lost around 20 species of bee in the UK alone - and a further 35 are at risk. A number of factors are conspiring against our bees. Find out what part pesticides play in the decline of our bee populations.
From bumble bees to solitary bees, we rely on each species to help pollinate our plants and crops.
While loss of habitat and climate change are key factors, the impact of pesticides – specifically neonicotinoids – is thought to be playing a huge part in our critically declining bee populations.
How neonicotinoids affect bees
Neonicotinoids – or neonics – are systemic pesticides, which means they are absorbed into every part of the plant – from the roots and stem, to leaves and flowers. When a bee feeds on the pollen or nectar containing neonicotinoids, the neonic can damage its nervous system and motor function, affecting its feeding, navigation, foraging and reproduction.
Impacts on wildlife and the wider environment
New evidence shows that these pesticides aren’t only found on the crops they’re intended for. High levels of neonics are being detected on wildflowers and hedgerows around fields of treated crops, which means the bees can’t escape them, and other wildlife is also at risk.
For example, it’s been shown that neonic seed treatments are washed-off by rain and contaminate soils. And neonics have been found to affect the earthworms that are essential for keeping our soil healthy.
Neonicotinoids and the EU ban
In 2013, three of these pesticides were restricted across the EU following a vote of European Member States. This move was vigorously opposed by the UK despite the scientific evidence that they posed a “high acute risk” to honeybees.
Since then scientific evidence of their threat to bees – and other wildlife– has grown stronger still.
Next year the EU will vote on whether to continue the ban in the light of new research. We see the evidence getting stronger, and expect restrictions in Europe to remain. A recent survey found that 81% of the British public want the government to maintain the EU ban on bee-harming pesticides.
As the UK heads for Brexit, we’ll be pushing our government to commit to tough environmental legislation that protects our wildlife - and not to give in to pesticide industry lobbying.
Reasons for a ban on neonicotinoids
1. Neonicotinoids harm bees (and other wildlife)
Compelling scientific evidence includes research from both laboratory studies and field trials, such as:
- In June 2014 a global study involving 29 scientists and over 1,000 papers by the Global Task Force on Systemic Pesticides concluded that neonicotinoids “are causing significant damage to a wide range of beneficial invertebrate species and are a key factor in the decline of bees”.
- In April 2015, the highly respected European Academies Science Advisory Council said there is clear scientific evidence for sub-lethal effects on bees and other pollinators exposed to very low levels of neonicotinoids over extended periods.
- A study by Newcastle University, published in April 2015, found that bees preferred to feed on solutions containing neonicotinoids, and concluded that treating flowering crops with commonly used neonicotinoids “presents a sizeable hazard to foraging bees”.
- Field trials in Sweden found the use of neonicotinoid treated seeds “has negative effects on wild bees, with potential negative effects on populations".
- In 2016 the Centre for Ecology and Hydrology published an eighteen year study that showed a correlation between neonicotinoid use and the decline of wild bees.
- Evidence is growing that neonicotinoids may also be affecting butterflies including a study by the University of Stirling which showed that the decline of 15 out of 17 butterfly species monitored correlated with neonicotinoid use.
2. Bees are being exposed to more neonicotinoids than previously thought
A study found that wild-flowers like poppies growing next to fields of crops treated with neonicotinoid, contain high levels of these pesticides. Poppies, and other wildflowers, are an important source of food for bees.
Meanwhile research from Canada found that neonicotinoids remain much longer than expected in soil dust, and that the dust is dispersed widely, potentially increasing bees exposure to them.
In 2016 EFSA concluded that there is a high risk to bees exposed to the neonicotinoid clothianidin via dust drift from when treated cereal crops like wheat are sown. There is also a high risk from exposure via flowering crops grown after a treated crop such as winter wheat, because of the persistence of the chemical in the soil.
Because research is showing neonics remain in the environment and are found a long way from where they were used there is now a strong case to extend existing restrictions - which only apply to some crops like oilseed rape - to all crops such as wheat.
3. There is a lack of evidence that neonicotinoids help farmers
The National Farmers Union (NFU) says there are crop losses due to damage from cabbage stem flea beetle (CSFB), resulting from the restrictions on neonicotinoids.
As a result, the NFU successfully persuaded the government to allow oilseed rape treated with 2 of the restricted pesticides to be planted in parts of the country in 2015. But when it tried to do the same in 2016 the government rightly turned the application down keeping our oilseed rape fields free of the banned pesticides.
Actually yields for oilseed rape in 2015, when neonics could not be used, were higher than in 2014 and above the ten year average. Although yields in 2016 are looking to be below the five year average, this is due to a range of factors including weather, with loss to pests being only one.
Some farmers will have suffered crop losses due to pests, but these could have happened even with neoincotinoid treated seeds. In fact one study found no consistent benefit on crop yield from using treated seeds.
What we do have evidence for is that insect pollination enhances oilseed rape yields - and has also been found to increase the value of 2 British apple varieties by £37m a year.
Now new research suggests that neonicotinoids could be damaging some food production. Apples pollinated by bumblebees exposed to neonics were lower quality than neonic-free bumblebees
We found that bees exposed to pesticides returned from apple flowers with less pollen than bees in the control group. This suggests that bumblebees exposed to pesticides must somehow behave differently on flowers.
Dr Mike Garratt, University of Reading
4. There are alternative ways of controlling pests
The NFU says that farmers will be forced to use more of other pesticide sprays such as pyrethroids if the neonicotinoid ban continues. I'ts true that some farmers have used more of these sprays, but we believe there is no need to.
Research for Friends of the Earth found that there are effective non-chemical means of control, such as encouraing natural predators that eat the pests. Measures to help natural predators like planting wildflower margins and hedgerows can be good for pollinators too.
Pesticide use can also be reduced if crops are carefully monitored for pests before a decision is taken to use a chemical. If sprays are only used as a last resort the pests are less likely to develop resistance too.
Friends of the Earth has talked to farmers who grow oilseed rape without neonicotinoids. Farmers need more support from the government and the farming industry to develop other promising methods of pest control such as companion cropping which may help to draw pests away from the crop.
Friends of the Earth’s Bee Cause continues to campaign and put pressure on the Government to safeguard and extend the restrictions on the use of these deadly pesticides.
Last updated November 2016