Jul 19

Bumblebees imported from Europe infected with parasites pose a serious threat to the UK’s wild and honey bee populations, according to a new study.

Honey bee image

Honey bees are vital pollinators

Deadly imports

Each year, more than a million bumblebee colonies are imported by countries across the globe to pollinate a variety of crops, with the UK alone importing between 40,000 and 50,000. Although the colonies are said by the global suppliers to be disease free, a recent study in the Journal of Applied Ecology has found that more than three-quarters of those imported into the UK each year are riddled with parasites.

Bees and disease

Scientists purchased 48 commercially produced bumblebee colonies, each containing up to 100 bees, from three different European suppliers during 2011 and 2012, and screened each one for parasite DNA. The results showed that an alarming 77% of the colonies were infected with parasites, a situation which has serious implications for the health of the UK’s native wild bees and honey bees, many of which are already suffering severe declines.

These parasites will undoubtedly be spilling over into wild and honey bees and very probably having negative effects on them,” said lead researcher Professor William Hughes, from the University of Sussex. “It is no great leap to think that damage is already being done.”

Honey bee worker image

Parasites carried by imported bumblebee colonies may pose a serious risk to the UK’s native bee populations


The results of the study revealed that the imported bumblebee colonies carried several different parasites, five of which were found in the bees themselves and three in the pollen provided by the suppliers as food. These parasites included three main bumblebee parasites (Crithidia bombi, Nosema bombi and Apicystis bombi), three honey bee parasites (Nosema apis, Ascosphaera apis and Paenibacillus larvae), and two which infect both bumblebees and honey bees (Nosema ceranae and deformed wing virus).

With the decline of pollinating insects in the UK in recent years, food producers are becoming increasingly reliant upon imported bees.

Over a million colonies are imported globally – it’s a huge trade,” said Professor Hughes. “A surprisingly large number of these are produced in factories, mainly in Eastern Europe. We couldn’t grow tomatoes in this country without these bumblebees. We sought to answer the big question of whether colonies that are being produced now have parasites and, if so, whether those parasites are actually infectious or harmful.”

Buff-tailed bumblebee image

Scientists are calling for stricter regulations regarding the import of bumblebees

Severe consequences

The potential impacts on native wild bee and honey bee species could be extremely severe, from harming the bees’ ability to learn, which is vital for finding food, to killing them outright. In Argentina, native bee species are already being driven to extinction as a result of imported parasites, and the authors of the recent study are recommending that urgent action is required in the UK to improve the effectiveness of disease screening and to close damaging loopholes.

Call for action

Scientists are calling for authorities to strengthen measures to prevent the importation of parasite-infected bumblebee colonies, by introducing proper colony checks upon arrival in the UK. While there are strict regulations in the UK regarding the import of non-native bumblebees, including ensuring that the colonies are disease free and are only kept in hives from which the queens cannot escape, no such regulations apply to imported colonies of native bee subspecies.

Bees and other pollinators are responsible for the production of three-quarters of the world’s food crops, but heavy pesticide use, rising disease, and starvation due to habitat destruction are all contributing to worrying declines in many species.

The introduction of more or new parasite infections will, at a minimum, exacerbate this, and could quite possibly directly drive declines,” said Professor Hughes.

Honey bee image

Honey bee in flight, laden with pollen

Pesticide ban

Earlier this week, the EU voted to successfully suspend the use of fipronil, a common pesticide, due to the serious risk it poses to bees. Currently used in more than 70 countries, this insect nerve agent will be banned from use on corn and sunflowers in Europe from the end of 2013.

Tonio Borg, European Commissioner for Health, said, “In the aftermath of the restriction on use of neonicotinoids, I pledged to do my utmost to protect Europe’s honey bee population, and today’s agreement with member states not only delivers on that pledge but marks another significant step in realising the commission’s overall strategy to tackling Europe’s bee decline.”

Read more on this story at BBC News – Imported Bumblebees pose ‘parasite threat’ to native bees and The Guardian – Imported bumblebees pose risk to UK’s wild and honeybee population – study.

Find out more about honey bees on ARKive.

Kathryn Pintus, ARKive Text Author

Apr 29

Neonicotinoid pesticides blamed for bee deaths are to be banned across Europe after an EU vote which took place today.

Photo of honey bee heavily laden with pollen

Honey bees are vital pollinators, but are in decline

Wild species such as honey bees are believed to be responsible for the pollination of around a third of the world’s crops, and contribute billions of dollars each year to the global economy. However, there has been widespread concern about their rapid decline, which has been blamed on a number of factors, including habitat loss, disease and the use of insecticides.

Neonicotinoids are nicotine-like chemicals which are toxic to insects and which have been widely used as pesticides for more than a decade. They are usually applied to seeds, and are taken up by all parts of the growing plant, including its pollen and nectar.

Although less harmful than some of the pesticides they replaced, neonicotinoids have been blamed for contributing to bee declines, with a number of studies showing harmful effects on bee behaviour and survival. The combined effects of more than one pesticide have also been shown to put bumblebee colonies at risk.

Photo of buff-tailed bumblebee

Pesticides have also been shown to have negative effects on bumblebees

However, many farmers and chemical companies argue that the science is inconclusive and the studies do not necessarily reflect field conditions, and that a ban on these pesticides would harm food production.

Intense lobbying

There has been intense lobbying by both sides in the run-up to today’s vote, with nearly 3 million signatures collected in support of a ban, and campaigners rallying in London last Friday to call for action.

Some countries, including Germany, Italy and France, have already put restrictions on neonicotinoids, while some UK retailers have taken action by removing them from their shelves and supply chains.

A previous vote by the EU on whether to ban the chemicals was inconclusive, so the European Commission went to an appeals committee. Fifteen countries have now voted in favour of a ban, while eight voted against, including the UK, and four abstained. Although not a large majority, this was enough for the Commission to put in place a two-year ban on neonicotinoids.

Photo of honey bee bees at entrance of hive

Other threats to bees include habitat loss and disease

After the vote, the EU Health Commissioner Tonio Borg said, “I pledge to do my utmost to ensure that our bees, which are so vital to our ecosystem and contribute over 22 billion Euros ($29 billion) annually to European agriculture, are protected.”

More to be done for bees

Speaking about the vote, Andrew Pendleton of Friends of the Earth said, “This decision is a significant victory for common sense and our beleaguered bee populations. Restricting the use of these pesticides could be an historic milestone on the road to recovery for these crucial pollinators.”

The new ban will prohibit the sale and use of seeds treated with neonicotinoids, and will also prohibit the sale of these chemicals to amateur growers. However, it will not apply to crops that are non-attractive to bees, or to crops that are grown over winter.

Some have warned that the ban could lead to the return of older, more harmful pesticides. However, supporters say that this has not happened in countries that have already banned the chemicals, and that the use of more natural methods of pest control can tackle any problems.

Photo of honey bee in flight carrying pollen

Bees are estimated to be worth billions of dollars to the global economy

Few people would disagree that we need to protect our food production, but it shouldn’t be at the cost of damaging the environment. Indeed, there are several alternatives to using neonicotinoids, and other pesticides, and this a great opportunity for farmers to adopt these practices to protect bees and other pollinators,” said Professor Simon Potts, a scientist at the University of Reading.

A short-term decision to keep using harmful products may be convenient, but will almost certainly have much greater long-term costs for food production and the environment,” he said.

Although the ban is good news for bees, these important pollinators still face a number of other threats, and more still needs to be done to protect them. A monitoring programme will also be needed to assess the effects of the two-year ban on bees and other pollinating insects.


Read more on this story at BBC News – Bee deaths: EU to ban neonicotinoid pesticides and The Guardian – Bee-harming pesticides banned in Europe.

View photos and videos of bees on ARKive.

Liz Shaw, ARKive Text Author

Oct 23

Pesticides used in farming are killing bumblebees and affecting their ability to forage, putting colonies at risk of failure, according to a new study.

Photo of a buff-tailed bumblebee

Buff-tailed bumblebee on flower

An estimated one-third of all plant-based foods eaten by humans rely on bees for pollination, and bees and other pollinators have been estimated to be worth around $200 billion a year to the global economy. However, bee numbers have been plummeting in recent years, particularly in North America and Europe.

As bees provide around 80% of pollination by insects, it is vital to understand and deal with the causes of these declines.

Colony effects

Recent studies have suggested that pesticides may play a role in bee declines, as pesticide exposure can cause changes in bee behaviour and reduce the production of queens in colonies. However, the overall effects at the colony level are less well understood. Bees are also exposed to a number of different pesticides while foraging, but their combined effects have rarely been investigated.

Photo of honey bee performing waggle dance

Honey bees

In the new study, published in Nature, scientists exposed colonies of bumblebees to the pesticides neonicotinoid and pyrethroid over four weeks, at levels similar to those found in the field.

Most previous studies have focused on honey bees, which are smaller than bumblebees but have much larger colonies, sometimes numbering tens of thousands of individuals. In contrast, bumblebees form colonies of just a few dozen individuals, potentially making them more vulnerable to impacts at the colony level.

Photo of a small garden bumblebee nest

Nest of the small garden bumblebee

The findings showed that long-term exposure to the two pesticides impaired the foraging behaviour of the bees and increased worker mortality, leading to significant reductions in colony success. The researchers also found that being exposed to a combination of more than one pesticide increased the likelihood of a colony failing.

Effects at the individual level can have a major knock-on effect at the colony level. That’s the novelty of the study,” said Richard Gill, the lead author of the study.

Important piece of the jigsaw

According to the researchers, the new findings emphasise the need for wider testing of pesticides. They endorsed the recommendations of the European Food Safety Authority (EFSA) that pesticides should be tested over longer periods and that new protocols should be developed to detect the cumulative effects of multiple chemicals on bees. There should also be separate assessments for different bee species.

Photo of female common carder bumblebee feeding from flower

Common carder bumblebee foraging

Parasites and habitat destruction, leading to a reduction in food supplies, have also been blamed for the decline in bee populations. A number of different factors are likely to be involved, and more research is still needed.

My guess is that the decline of bees is like a jigsaw – there are probably a lot of pieces to put into place. This is probably a very important piece of that jigsaw,” said Gill.

Read more on this story at The Guardian – Pesticides put bumblebee colonies at risk of failure, study finds.

View photos and videos of bees on ARKive.

Liz Shaw, ARKive Text Author

Oct 11

Scientists are to investigate a possible connection between diesel fumes and the global decline of honey bees.

Honey bee image

Honey bee worker feeding

A proposed three-year study by scientists at the University of Southampton will attempt to discover whether or not tiny particles, known as nanoparticles, produced by diesel engines are affecting honey bee numbers across the globe.

Faulty navigation: finding their way through the fumes

Despite being widespread, honey bees are under serious threat. Human activities, including the accidental introduction to the UK of the devastating varroa mite Varroa jacobsoni, have long been blamed for declines in bee populations, and it appears that the production of diesel fumes may soon be added to the list.

Honey bees are great navigators, and foraging bees are known to perform complicated dances to other members of their hives to direct them to newly discovered food supplies.  Yet scientists believe that nanoparticles from diesel fumes could be affecting the bees’ brains and their navigational abilities, preventing the worker bees from finding their way back to the hive.

Honey bee image

Honey bee performing a round dance

Chemical ecologist Dr Robbie Girling believes that the nanoparticles may also cause other problems for these social insects: “The diesel fumes may have a dual effect in that they may be mopping up flower smells in the air, making it harder for the bees to find their food sources.”

Flight of discovery

The study will call upon the expertise of biologists, nanotechnology researchers and ecologists at the university to test behaviour and neurological changes observed in honey bees when they are exposed to diesel fumes. Nanoparticle exposure at high doses is known to be damaging to the brains of other animals, and the scientists are keen to find out if the same is true for honey bees.

We want to find out if bees are affected in the same way – and answer the question of why bees aren’t finding their way back to the hive when they leave to find food,” said ecologist Professor Guy Poppy.

Honey bee image

Honey bee in flight carrying pollen

Double trouble

The decline in honey bee numbers is a sad state of affairs for biodiversity as a whole, with the reported loss of tens of thousands of beehives every year since 2007 potentially leading to a reduction in wildflower pollination. Yet it is also of great concern to human populations, as bees contribute billions to the world economy through the pollination of crops, honey production, and supporting employment. In the UK alone, bees are estimated to contribute £430 million a year in ecosystem services and honey.

The collapse of bee populations has been recorded across the globe, with an unexplained 35% drop in the number of U.S. hives in 2007, 2008 and 2009, yet extensive research to determine the exact causes of such declines has yet to be carried out. It is hoped that this new study might provide some answers which could contribute to the continued survival of this important species.

Read more on this story at BBC News – Southampton scientists probe link between diesel and bee decline.

View photos and videos of the honey bee on ARKive.

Kathryn Pintus, ARKive Species Text Author

Mar 10

Bee colonies worldwide are under threat, with serious implications for biodiversity and food security, a new UNEP report suggests.

Bees are perhaps the most economically important group of pollinators. Around 90% of the world’s food is provided by around 100 crop species – and more than 70 of these are pollinated by bees.

Photo of honey bee worker feeding

Honey bee worker feeding.

Mystery disappearance

The mysterious collapse of honey bee colonies in the U.S., Europe and Asia, and the unexplained decline of wild bee pollinators globally, is an increasingly common phenomenon known as ‘colony collapse disorder’.

The report, entitled ‘Global Bee Colony Disorders and Other Threats to Insect Pollinators’, warns that the disappearance of bees could have a profound effect on global food supplies.

Photo of honey bee performing waggle dance

Honey bee colony.

‘More than a dozen threats’ to declining bees

Compiled by some of the world’s leading honey bee experts, the report highlights more than a dozen factors which may be contributing to the increasing bee decline.

The emergence of new kinds of pathogens and disease are proving deadly to bees and other key pollinators, and the rapid spread of these diseases around the world has been facilitated by increasing globalisation and international trade. The parasitic mite Varroa destructor has also been identified as a serious threat, spreading viral diseases as it feeds on the circulatory fluid of the bees and moves from one colony to another.

Air pollution is thought to be affecting the ability of bees to detect the scent of flowers, while many chemicals that are used in agriculture have been found to be damaging to bees, with some combinations of pesticides acting as a ‘lethal cocktail’.

The report also estimates that unless conservation efforts are stepped up, as many as 20,000 flowering plant species could be lost over the coming decades, removing vital food and habitat upon which many bee species depend.

Photo of honey bee feeding

Honey bee feeding.

Climate change is also likely to exacerbate the problems being faced by bees, altering flowering and rainfall patterns and affecting the quality and quantity of nectar supplies.

Declines likely to continue

According to Achim Steiner, the UN Under-Secretary-General and UNEP Executive Director, “The way humanity manages or mismanages its nature-based assets, including pollinators, will in part define our collective future in the 21st century.”

“Bees underline the reality that we are more, not less dependent on nature’s services in a world of close to seven billion people”.

Without drastic changes to the way that humans manage the planet, the current declines in pollinators needed to feed a growing global population are likely to continue, the report concludes.

Read the full report: ‘Global Bee Colony Disorders and Other Threats to Insect Pollinators

Helen Roddis, ARKive Species Text Author


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