Pesticide exposure causes bumblebee flight to fall short

APRIL 29, 2019

by Imperial College London

Bees exposed to a neonicotinoid pesticide fly only a third of the distance that unexposed bees are able to achieve.

Flight behaviour is crucial for determining how bees forage, so reduced flight performance from pesticide exposure could lead to colonies going hungry and pollination services being impacted.

Foraging bees are essential pollinators for the crops we eat and the wildflowers in our countryside, gardens and parks. Any factor compromising bee flight performance could therefore impact this pollination service.

A study by Imperial College London researchers, published today in the journal Ecology and Evolution, reveals how exposure to a common class of neurotoxic pesticide, a neonicotinoid, reduces individual flight endurance (distance and duration) in bumblebees.

The study shows that bees exposed to the neonicotinoid imidacloprid in doses they would encounter in fields fly significantly shorter distances and for less time than bees not exposed, which could reduce the area in which colonies can forage for food by up to 80 percent.

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Neonicotinoids at 'chronic levels' in UK rivers, study finds

14 December 2017

Rivers across the country are "chronically polluted" with pesticides believed to pose a threat to bee populations, a report has found.

The River Waveney on the Norfolk/Suffolk border was found to have the highest levels of neonicotinoids in the UK.

The River Wensum in Norwich, and the River Tame in the West Midlands were also named among the most polluted.

According to figures from UK monitoring data by the European Environment Agency, 88% of sites in Britain were contaminated with neonicotinoids.

The Angling Trust, the charity Buglife, and The Rivers Trust said eight rivers in England - including the Ouse, Somerhill Stream, Wyke Beck, Ancholme, and Sincil Dyke - exceeded recommended chronic pollution limits.

The River Waveney's pollution limit was exceeded for a whole month, they said.

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Why has Labour included bees in its manifesto?

Leaked draft says Labour will protect bees by banning all neonicotinoid pesticides, which have been linked to species decline

Sandra Laville

Thursday 11 May 2017 12.43 BST Last modified on Thursday 11 May 2017 13.37 BST

If you were wondering why bees popped up in the Labour party’s leaked manifesto this week, then here’s the answer.

Since 1900 about 20 bee species have become extinct in the UK and 35 more are now at risk.

According to the Department for the Environment, Food and Rural Affairs, between 1980 and 2010, 51% of pollinator species – including all bee species and wasps – became less widespread, with 36% showing a strong decrease.
 

The threats to the diversity of bee populations include climate change, loss of habitat and – evidence suggests – use of neonicotinoid pesticides.

But the extent to which neonics, as they are known, are the cause of bee population declines is contested between environmental campaigners, and farming and pesticide groups who say their use is vital for crop protection.

In 2013 the EU imposed a partial moratorium on three neonics – imidacloprid and clothianidin, produced by chemical company Bayer, and thiamethoxam, produced by Syngenta.

Until now the moratorium on neonics has only covered their use on flowering crops, which in the UK are predominantly oil seed rape.

Labour in its manifesto adopts a tougher position – one the EU itself is considering introducing. If elected the party would impose a ban all neonicotinoid pesticides, which would stop them being used on non-flowering crops such as wheat and sugarbeet. One of the most recent studies on the impact of neonics on bees was published last year by the Centre for Ecology and Hydrology. It suggested their use correlated with “wild bee biodiversity losses at a national scale.” 

 

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Neonicotinoid pesticide reduces egg development in wild bumblebee queens

May 3, 2017

New research published in the journal Proceedings of the Royal Society B has found that wild bumblebee queens are less able to develop their ovaries when exposed to a common neonicotinoid pesticide

The research was conducted by Dr Gemma Baron , Professor Mark Brown of Royal Holloway, University of London and Professor Nigel Raine, (now based at the University of Guelph).

The study investigated the impact of exposure to field-realistic levels of a neonicotinoid insecticide (thiamethoxam) on the feeding behaviour and ovary development of four species of bumblebee queen.

Reduced ovary development across bee species

Lead author, Dr Baron said, "We consistently found that neonicotinoid exposure, at levels mimicking exposure that queens could experience in agricultural landscapes, resulted in reduced ovary development in queens of all four species we tested."

She continued, "Impacts of neonicotinoid exposure on feeding behaviour were species-specific, with two out of four species eating less artificial nectar when exposed to the pesticide. These impacts are likely to reduce the success of bumblebee queens in the spring, with knock-on effects for bee populations later in the year" added Baron.

As the first to examine the impacts of these chemicals across multiple bumblebee species, this study is an important contribution to understanding the potential costs of using this class of insecticides.

Dr Baron explained, "Previous studies have focused on a single bumblebee species and examined impacts in workers and established colonies. Bumblebee populations rely on spring queens to succeed, and by looking at the impacts of thiamethoxam on multiple species of spring queens, we have gained a step-change in our understanding".

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Europe should expand bee-harming pesticide ban, say campaigners

 The threat posed to bees by neonicotinoid pesticides is greater than perceived in 2013 when the EU adopted a partial ban, new report concludes

 

Staff and agencies

Thursday 12 January 2017 14.55 GMT 

Europe should expand a ban on bee-harming pesticides in light of a new report warning of widespread risks to agriculture and the environment, Greenpeace has said.

The report by biologists at the University of Sussex and commissioned by Greenpeace, concluded that the threat posed to bees by neonicotinoid pesticides was greater than perceived in 2013 when the European Union adopted a partial ban.

“New research strengthens arguments for the imposition of a moratorium” on the use of three neonicotinoids – clothianidin, imidacloprid and thiamethoxam, the analysis concluded.

“It has become evident that they pose significant risks to many ... organisms, not just bees.”

A global review last November said about 1.4bn jobs and three-quarters of all crops depend on pollinators, mainly bees.

There are some 20,000 species of bees responsible for fertilising more than 90% of the world’s 107 major crops.

Last year, the United Nations said 40% of invertebrate pollinators - particularly bees and butterflies - risk global extinction.

Bee populations have been hit in Europe, North America and elsewhere by a mysterious phenomenon called “colony collapse disorder”.

The blight has been blamed on mites, a virus or fungus, pesticides, or a combination of factors.

“These essential insects are in serious trouble,” Greenpeace wrote in a foreword to the report published on Thursday, which its authors said involved analysing hundreds of scientific studies published since 2013.

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