The most widely used pesticides are likely to be banned across the EU after a study revealed they do represent a risk to wild bees and honey bees.

A new assessment confirming the dangers of three neonicotinoid pesticides on bees has prompted calls for a total ban on the use of the chemicals in the countryside.

Use of the three pesticides is already restricted in the European Union on crops such as oil seed rape, because of the concerns they have 'sub-lethal' effects such as harming the bees' ability to forage and form colonies.

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Most uses of pesticides known as neonicotinoids represent a risk to wild bees and honeybees (pictured), European experts have warned

The assessment by the European Food Safety Authority (Efsa), which looked at the impacts on wild solitary bees and bumblebees as well as honeybees, has confirmed that most uses of the chemicals pose a risk to the insects.

It updates a 2013 analysis which led to the European Commission imposing the controls on use of the substances.

The European Commission has since proposed extending restrictions to only allow use on plants in greenhouses, extending the ban to crops such as sugar beet and winter cereals with seed treated with the chemicals.

Environment Secretary Michael Gove has said a total ban in the countryside would be supported by the UK and kept in place after Brexit.

Jose Tarazona, head of Efsa's pesticides unit, said that 'overall the risk to the three types of bees we have assessed is confirmed'.

WHAT ARE NEONICOTINOIDS? Neonicotinoids are neuro-active chemicals similar to nicotine that have proved to be highly effective at protecting crops from pests, especially aphids and root-eating grubs. They can either be sprayed on leaves or coated on seeds, in which case they infiltrate every part of the growing plant. Years of research have shown that under controlled conditions the chemicals are toxic to honey bees and bumblebees, causing brain damage that can affect learning and memory and impair their ability to forage for nectar and pollen. The chemicals are a key battleground in the environmental movement – with campaigners demanding a 'complete and permanent' ban on the pesticides as they are suspected to be harmful to bees. Only two to 20 per cent of the neonicotinoids, which are still used on crops such as wheat, are taken up and the rest is left on the soil. Samples taken in October revealed 75 per cent of samples from around the world contain the chemicals. Researchers tested 198 honey samples and found three out of four were laced with at least one of the neonicotinoid chemicals. For the study, an international team of European researchers tested almost 200 honey samples from around the world for residues left by five different neonicotinoids. While in most cases the levels were well below the EU safety limits for human consumption, there were exceptions. Honey from both Germany and Poland exceeded maximum residue levels (MRLs) for combined neonicotinoids while samples from Japan reached 45 per cent of the limits. Samples from England had neonicotinoid levels that were no more than 1.36 per cent of the amount thought to be safe for human consumption. Advertisement

Bees can be exposed to the pesticides by foraging on flowering crops in the field, from pollen and nectar which contain residues of the chemicals.

They can also be exposed through plants in the vicinity of the crop which have been contaminated by dust drifting away from the field and through contaminated soil, Efsa said.

Friends of the Earth called for an urgent outdoor ban on the chemicals, with campaigner Sandra Bell warning 'we have been playing Russian roulette with the future of our bees for far too long'.

'The UK Government has already said it will support a complete ban on the outdoor use of these three bee-harming chemicals – a move that is fully justified by this report. Other EU countries must now back a tougher ban too.

She added: 'Ministers must also use their post-Brexit farming policy to help our farmers to work in harmony with nature – and not against it.

'This must include an overhaul of the pesticide approval process, and a reduction in their overall use.'

🐝Great news! 🐝 EU food safety watchdog @EFSA_EU confirms dangerous #neonics pesticides are a serious threat to our bees – now EU Member States must urgently back a tougher ban. Our reaction >> https://t.co/9fT44I96Je pic.twitter.com/Qvcdo7OKVY — Friends of the Earth #BlackLivesMatter (@foeeurope) February 28, 2018

WHAT IS THE HONEYBEE CRISIS? Honeybees, both domestic and wild, are responsible for around 80 per cent of worldwide pollination, according to Greenpeace. But bee colony collapses across the globe are threatening their vital work. Bees are dying from a combination of pesticides, habitat destruction, drought, nutrition deficit, global warming and air pollution among other factors. The global bee crisis can potentially be solved if dangerous pesticides are eliminated, wild habitats are preserved and ecological agriculture is restored, according to Greenpeace (file photo) Greenpeace has reported: 'The bottom line is that we know humans are largely responsible for the two most prominent causes: Pesticides and habitat loss.' This is important for a number of reasons, chief among them the amount of work bees put into our food production. Vegetables, nuts and fruits are pollinated by bees. Of the top human food crops, a whopping 70 of 100 are pollinated by the creatures, which account for as much as 90 per cent of global nutrition. Greenpeace has suggested the following solutions to the problem: The preservation of wild habitats in order to protect pollinator health

The restoration of ecological agriculture

The elimination of the world's most dangerous pesticides Advertisement

Commenting on the report, Dr Philip Donkersley from Lancaster University, said: 'All three neonicotinoids evaluated here show high risk for exposing bumblebees through the pollen and nectar that they feed on.

'This exposure affects solitary bee reproduction, colony viability and learning ability in bumblebees.'

Professor Christopher Connolly, from the University of Dundee, said the study showed high risks did not come from direct contact to non-flowering crops, but from indirect exposure in field margins and nearby crops or those grown afterwards.

He warned the greatest risk to bees was from ongoing exposure due to the persistence of the pesticides and their transfer to other flowering plants, and constant low-level pollution could also increase the resistance of pests to the chemicals.

'A highly restricted use of neonicotinoids would reduce this environmental stress and retain neonicotinoids as important pest control agents for use in severe situations,' he suggested.