Bees and Varroa by dfsdf224s


									                   Bees and Varroa
                   Standard Note:     SN/SC/446
                   Last updated:      27 October 2010
                   Author:            Christopher Barclay
                   Section            Science and Environment Section

•   There has been a dramatic decline in bee numbers worldwide

•   The reasons for the decline are unclear. Possibilities include some environmental stress,
    pesticides, combined with weakness from diseases like varroa.

•   The decline could seriously affect pollination of orchards.

•   Defra launched a Bee Health Plan in 2009, including £10m to be spent on research into
    pollinators, including honey bees.

•   A Public Accounts Committee report in 2009 – after the launch of the Bee Health Plan -
    called for a higher priority for honey bees

•   Varroa has spread through the British bee population since about 1990. Treatments have
    been developed but the bees may be left seriously weakened.

•   News from the USA in May 2010 of further extensive losses has raised concerns that
    honey bees might be in terminal decline.

•   The British Beekeepers Association reported further losses in the 2009/10 winter, but less
    than in 2008/9.

•   US research suggests that colony collapse results form a combination of a virus and a

•   UK research suggests that the decline in pollinators is partly caused by certain wild plants
    being out-competed by other plants, so that less nectar is available for bees.

•   More Information is available on a useful Defra page- Bee Health.

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1       Dramatic decline in bee population                                                                 2 

2       Will the reduction in bee numbers damage pollination of orchards?                                  4 

3       Defra Bee Health Plan, 2009                                                                        4 

4       Westminster Hall debate, April 2009                                                                6 

5       Public Accounts Committee wants a higher priority for honeybees                                    6 

6       Varroa and its treatment                                                                           7 

7       Other threats to bees                                                                              8 

8       Colony Collapse Disorder                                                                           9 

9       The effect of changes in land use                                                                  9 

1        Dramatic decline in bee population
An article in the Observer on 1 May 2010 is the latest to be alarmed by the situation of bees
in the USA and worldwide:

         Disturbing evidence that honeybees are in terminal decline has emerged from the
         United States where, for the fourth year in a row, more than a third of colonies have
         failed to survive the winter.

         The decline of the country's estimated 2.4 million beehives began in 2006, when a
         phenomenon dubbed colony collapse disorder (CCD) led to the disappearance of
         hundreds of thousands of colonies. Since then more than three million colonies in the
         US and billions of honeybees worldwide have died and scientists are no nearer to
         knowing what is causing the catastrophic fall in numbers.

         The number of managed honeybee colonies in the US fell by 33.8% last winter,
         according to the annual survey by the Apiary Inspectors of America and the US
         government's Agricultural Research Service (ARS). (...)

         A global review of honeybee deaths by the World Organisation for Animal Health (OIE)
         reported last week that there was no one single cause, but pointed the finger at the
         "irresponsible use" of pesticides that may damage bee health and make them more
         susceptible to diseases. Bernard Vallat, the OIE's director-general, warned: "Bees
         contribute to global food security, and their extinction would represent a terrible
         biological disaster." 1

In February 2009, the New Scientist summed up the worldwide crisis:

     “Fears for crops as shock figures from America show scale of bee catastrophe”, Observer, 1 May 2010

        The world’s honeybees appear to be dying off in horrifying numbers, and now
        consensus is starting to emerge on the reason why: it seems there is no one cause.
        Infections, lack of food, pesticides and breeding – none catastrophic on their own – are
        having a synergistic effect, pushing bee survival to a lethal tipping point. (…)

        A third of our food relies on bees for pollination. Both the US and the UK report losing
        a third of their bees last year. Other European countries have seen major die-offs too:
        Italy, for example, said it lost nearly half its bees last year. The deaths are now
        spreading to Asia, with reports in India and suspected cases in China. 2

However, while the extent of the decline is generally accepted, there are doubts about the
existence of CCD as a disease:

        [T]o date researchers have found few clues as to the exact cause of the disorder. And
        some senior scientists now say the "disorder" does not exist as a separate illness. Dr
        Dennis Anderson, principal research scientist on entomology with the Australian
        research organisation CSIRO said the term could be distracting scientists from other

            "It's misleading in the fact that the general public and beekeepers and now even
            researchers are under the impression that we've got some mysterious disorder
            here in our bees. And so researchers around the world are running round trying to
            find the cause of the disorder - and there's absolutely no proof that there's a
            disorder there."

        His view is shared by some experts in the US. Conducting experiments at an isolated
        almond orchard in the Central valley area of California, Frank Eischen, of the US
        Department of Agriculture, said it was "probably true" that there was no new single

        "We've seen these kinds of symptoms before, during the seventies, during the nineties,
        now," he added. "It's probably not a unique event in beekeeping to have large
        numbers of colonies die." 3

In August 2009, the British Beekeepers Association (BBKA) annual survey of winter colony
losses showed losses of nearly 20%:

        Tim Lovett, BBKA President, said: “The improved figure is very welcome, compared
        with the 30.5% for winter 2007-08 but is way short of the 7-10% which until the last five
        years has been considered acceptable. 4

In May 2010, the British Beekeepers’ Association reported that 17 % of bee colonies were
lost over the 209/10 winter. There were significant regional variations, with 26% of colonies
lost in the North of England, compared to 12.8% in the South West. 5

The European Commission sent out standardized questionnaires throughout Europe to
obtain more information about the situation. They concluded that there was a lack of
information, especially in standardized form. In addition:

        Consensus of the scientific community about the multifactorial origin of colony losses in
        Europe and in the United States and insufficient knowledge of causative and risk
        factors for colony losses. 6

    “Honeybees under attack on all fronts”, New Scientist, 14 February 2009
    “'No proof' of bee killer theory”, BBC News Online, 5 March 2009
    BBKA News Release, Nearly 20% of the UK's Honey Bees Died Last Winter, 24 August 2009

2       Will the reduction in bee numbers damage pollination of orchards?
A study by ADAS in the late 1990s was reasonably optimistic about prospects of pollination.
It noted that many farmers who did not introduce hive bees felt that it would still be possible
to grow fruit in nature without honey bees or with a much reduced number:

        However, it is accepted that due to low populations of naturally occurring pollinating
        insects in some of the most intensive fruit production areas, that without the presence
        of hive bees, pollination could become a factor which would limit cropping potential.

        It is clear that the role of naturally occurring pollinating insects could become a vital
        component of successful fruit growing in the future. Even now it is claimed that when
        the weather is poor for pollination that the honey bee is a poor performer compared to
        other naturally occurring pollinating insects. At the present time, in years when
        weather conditions are good for pollination, the hive bee helps to contribute to an
        overset which subsequently has to be thinned by hand or chemically which adds to the
        cost of production of apples.

        A possible strategy for the future when fewer hives are available will be for fruit
        growers to take all possible steps to make more pollen available by planting additional
        pollinating varieties and Malus pollinator species. Further measures would be to
        improve the orchard environment with windbreaks, but most importantly to create
        conditions inside and around the orchard for pollinating insects, other than honey bees,
        to establish and thrive. The increased uptake of IPM methods of fruit growing is likely
        to play a part.

However, concerns over pollination have continued to increase. A Defra press release in
April 2009 noted:

        Pollinators – including honey and bumble bees, butterflies and moths – play an
        essential role in putting food on our tables through the pollination of many vital crops.
        These insects are susceptible to a variety of disease and environmental threats, some
        of which have increased significantly over the last five to ten years. Climate change, in
        particular warmer winters and wetter summers, has had a major impact on pollinators.
        As a result, the numbers of pollinators have been declining steadily in recent years,
        with the number of bees in the UK alone falling by between 10 and 15 per cent over
        the last two years. 8

In September 2010, the Daily Telegraph reported on research concluding that the decline in
pollination was actually taking place:

        Scientists have found that pollination levels of some plants have dropped by up to 50%
        in the past two decades. The “pollination deficit” could see a dramatic reduction in
        crop yields. The study, carried out in the Rocky Mountains, Colorado, is said to be a
        warning to Britain, which, if anything, ahs seen greater decline in bees and pollinators. 9

3       Defra Bee Health Plan, 2009
On 9 March 2009, Defra launched a plan to improve bee health:

    “Crisis may be over for honey bees as more survive winter”, Independent, 24 May 2010
    Pascal Hendrikx et al, Bee Mortality and Bee Surveillance in Europe, 2009
    Pollination of Horticultural Crops: the threat from Varroa (ADAS September 1996) p.6 and The Effect of Varroa
    Jacobsoni on the Pollination of Fruit Crops 1997 Update (ADAS, January 1998)
    Defra Press Release, £10 million initiative launched to tackle bee and pollinator decline, 21 April 2009
    “Bees’ decline puts crop yields at risk”, Daily Telegraph, 6 September 2010

          Defra and the Welsh Assembly Government have today published 'Healthy                    Bees', a
          plan to protect and improve the health of honey bees in England and Wales.               The ten
          year plan was drafted in consultation with beekeeping organisations and                  aims to
          sustain honey bee populations by supporting beekeepers to ensure                         effective
          biosecurity measures are adopted to minimise risk from pests and disease.

          This follows an investment of an extra £4.3 million to gather more information from
          beekeepers and undertake more research into the health of bees, announced by
          Environment Secretary Hilary Benn in January. Of this, £2 million over five years will
          contribute to a new research programme on pollinators, which is currently being
          developed with other funding partners.

          The first stage of the plan will attempt to identify and make contact with perhaps as
          many as 20,000 amateur beekeepers to make sure that they are aware of the need to
          alert the National Bee Unit (NBU) to bee health problems and encourage them to
          register on BeeBase, its beekeepers database. This will help ensure that any new or
          existing health problems are identified.

          The last two years have seen recorded losses of between 10 to 15 per cent in bee
          numbers although it is possible that real losses are significantly higher due to the
          number of beekeepers not in contact with the NBU.

          Honey bees contribute directly to local food production and make an important
          contribution, through pollination, to improving the yield of some crops. They are
          susceptible to a variety of disease and environmental threats, some of which have
          increased significantly over the last five to 10 years. (…)


          1. 'Healthy Bees' is available online at

          2. 'Healthy Bees' was launched after public consultation. Details of the consultation can
          be found:

          3. Defra recently announced new funding to help implement the plan. See the details:

On 21 April 2009, Defra announced a joint initiative increasing this money to £10m, to
identify reasons for the decline in bee numbers:

          To gain a better understanding of why this is happening, some of the UK's major
          research funders have joined together to launch an important new research
          programme. The biggest challenge will be to develop a better understanding of the
          complex relationships between biological and environmental factors which affect the
          health and lifespan of pollinators.

          The funding will be made available to research teams across the UK under the Living
          With Environmental Change (LWEC) partnership, the major initiative by UK funders to
          help the UK respond effectively to changes to our environment. This is a joint initiative
          from the Biotechnology and Biological Sciences Research Council (BBSRC), Defra,
          the Natural Environment Research Council (NERC), the Wellcome Trust and the
          Scottish Government. 11

     Defra Press Release, Jane Kennedy launches plan to halt declining Bee numbers, 9 March 2009
     Defra Press Release, £10 million initiative launched to tackle bee and pollinator decline, 21 April 2009

4        Westminster Hall debate, April 2009
On 29 April 2009, John Penrose opened a debate on honey bee health, saying that we had
something to celebrate, with £10m of research money from various sources. It was important
not to rely upon research conducted on honey bee health in other countries. He asked
several questions to which the Minister later replied and also said that we needed to
understand the purpose of BeeBase:

         It is important for the Minister to explain what the money is to be spent on, and what
         the Government’s intention is behind the building of BeeBase. This will not be a one-off
         job. Figures from the BBKA indicate that roughly 10 per cent. of the beekeeping
         population start or stop keeping bees in any one year, so there is a high rate of churn.
         The Government cannot build BeeBase as a one-off operation, as it will not be
         accurate. They must maintain the database, for whatever purpose it is intended, and
         that will not be cheap. The concern is that there might be an element of Big Brother on
         the horizon. At the back of the mind of someone in the Department, there might be the
         intention that once most beekeepers are enrolled, enrolment could become
         compulsory. Once it is compulsory, why should we not start charging beekeepers to
         register on BeeBase? That would be dangerous, because the British beekeeping
         population is different from that of other countries. It is not the same as in Australia, for
         example, where there is a smaller number of very large, industrial-scale commercial
         beekeeping operations. The vast majority of British bee hives are kept by small,
         hobbyist beekeepers, such as myself, who have two or three hives. 12

The Minister of State, Jane Kennedy, replied:

         To all those who have expressed concern about whether we should have a voluntary
         or compulsory registration scheme for beekeepers, I say that my instinct is always,
         wherever possible, to encourage co-operation through a voluntary method. If we look
         at the experience of other countries wrestling with the problem, we will see that there
         are mixed views on, and experience of, compulsory schemes. Although we may need
         to keep it under review, I prefer to proceed with a voluntary scheme.


         Another part of our plan relates to research. [W]e certainly hope to see the first project
         starting before the end of 2009. (...) I have been asked how much will be spent on
         honey bees from the research programme. I want to share with Members the carefully
         crafted advice that I have received on that:

         “I would expect the research allocation to be broadly proportionate to the importance of
         honey bees, relative to other pollinators.”

         The fact that we refer to our plan as the honey bee plan indicates how important we
         accept honey bees to be. They are, as the hon. Member for Weston-super-Mare rightly
         noted, the first pollinators out in spring. 13

5        Public Accounts Committee wants a higher priority for honeybees
On 14 July 2009, the Public Accounts Committee published a report on the health of
honeybees, with the following conclusions and recommendations:

     HC Deb 29 April 2009 cc255-61WH
     HC Deb 29 April 2009 cc276-8 WH

         1. Success in tackling disease incidence in honeybees and livestock will require the
         Department to work more collaboratively with farmers, beekeepers and leading
         academic researchers in these areas. The Department should pilot local consultative
         arrangements in livestock disease hotspots involving farmers, veterinarians and local
         authorities to adopt a collaborative approach to risk assessment, preventative actions
         and enforcement. A similar approach between beekeepers and the Department's
         inspectors would help to involve the key stakeholders actively in minimising risks and
         enforcing good bee husbandry in local areas. Before allocating its new honeybee
         research funding, the Department should discuss priorities with beekeeping
         associations and leading academic researchers in this area.

         2. By widening the focus of the additional research funding to cover other pollinating
         insects as well as honeybees, work into the underlying causes of the decline in
         honeybee numbers might not be enough to reverse this trend. The Department should
         specify which aspects of honeybee health it plans to research and what proportion of
         the additional funds are likely to be ring-fenced for this purpose.


         6. Only half of active beekeepers are registered with the Department and subject to
         the Department's inspection regime because, unlike in some other countries,
         registration is not compulsory. In maintaining a voluntary approach to registration and
         inspection, the Department should develop a strategy to increase significantly the
         number of registered beekeepers. This would enable it to enhance its data on bee
         disease incidence and better target advice on good husbandry and its research

         7. Reports of notifiable disease in honeybees are much lower in Scotland than in
         England and Wales, but the Department has no strategy for collaborating with the
         devolved administration in Scotland to manage the risks to honeybee colonies across
         the United Kingdom. The Department should work with bee inspectors and bee
         keepers in Scotland to obtain a greater understanding of the incidence of disease and
         colony loss, and to establish a common system for registering beekeepers and for
         measuring and reporting disease. 14

6        Varroa and its treatment
Varroasis is a condition caused by the parasitic mite (Varroa jacobsoni) which weakens
bees. Without a continuous treatment programme, this can lead to the decline and death of
the colony. It is difficult to detect in the early stages, spreads quickly and under European
conditions, eradication has proved impossible. More information is available on a useful
Defra page- Bee Health.

A PQ in May 2008 described the Government view:

         Tony Lloyd: To ask the Secretary of State for Environment, Food and Rural Affairs
         what recent assessment he has made of the risk to bee colonies of (a) the varroa mite
         and (b) other bee parasites.

         Jonathan Shaw [holding answer 15 May 2008]: The Varroa mite is ubiquitous and is
         probably in every honey bee colony in England and Wales. Although it is no longer a
         statutory requirement to notify the presence of Varroa, it poses a major threat to
         beekeepers. However, it can be kept under control with appropriate treatments and
         hive management techniques. The National Bee Unit provides written material on

     Public Accounts Committee, The health of livestock and honeybees in England, 14 July 2009 HC 366 2008-9

         Varroa management (available on their Beebase website) and issues advice to
         beekeepers both through comprehensive training sessions on effective management of
         Varroa and when visiting individual beekeepers.

         Other damaging parasites affecting honey bees include Nosema and Tracheal mites.
         Limited survey work has shown that two species of Nosema—N. apis and N.
         ceranae—are present in the UK. They have been found in widely dispersed locations.
         Tracheal mite is also widespread.

         There is a statutory requirement to notify the presence of Tropilaelaps mites which can
         affect brood and adult bees. They are found in Asia and have not been reported in

7        Other threats to bees
One concern is European foul brood:

         Mr. Willis: To ask the Secretary of State for Environment, Food and Rural Affairs what
         steps she is taking to address the increase in the incidence of European foulbrood in
         bee colonies.

          Jim Knight: Data provided by the National Bee Unit indicate that there has been a
         slight decline rather than an increase in the incidence of European foul brood disease
         in England in recent years. This year, 664 colonies were found infected with European
         foul brood compared to the 1007 cases recorded in 2000. The effectiveness of
         measures to control European foul brood is subject to continuous assessment by the
         National Bee Unit. The unit is currently evaluating the effectiveness of the shook
         swarm technique for improved control of the disease. If successful, this will eliminate
         the need for the application of antibiotic by bee health inspectors.

Another potential threat to bees may come from certain pesticides. On 23 May 2008 the website reported that the German Federal Office of Consumer Protection and
Food Safety (BVL) had suspended the registration for eight pesticide seed treatment
products used in rapeseed oil and sweetcorn, following reports from beekeepers in the
Baden-Württemberg region that two thirds of their bees died following the application of a
pesticide called clothianidin. 17 This was confirmed in a press release dated 11 June 2008
from the German Federal Office of Consumer Protection and Food Safety. 18 The press
release states that, although the pesticide clothianidin was assessed thoroughly for
hazardous effects to bees by the authorities as part of the authorisation procedure, a
preliminary investigation into the bee damage has suggested that “pneumatic seeding
machines can cause considerable dust drift with active substance abrasion, depending on
their construction, which could possibly lead to clothianidin contamination in bees and be
responsible for the bee damage.”

On 11 June 2008 Jonathan Shaw, Parliamentary Under Secretary of State, Department for
Environment, Food and Rural Affairs answered a PQ from Norman Baker MP on the
assessment of risk to the beekeeping industry from the use of clothianidin in the UK:

     HC Deb 21 May 2008 cc171-2W
     HC Deb 30 November 2005 c503W
17, Pesticides: Germany bans chemicals linked to honeybee devastation, 23 May 2008
     German Federal Office of Consumer Protection and Food Safety (BVL), Background information on endemic
     damage to bees in South Germany, 11 June 2008

         Norman Baker: To ask the Secretary of State for Environment, Food and Rural Affairs
         what assessment he has made of the risks posed by the agricultural use of clothianidin
         and other neonicotinoid pesticides to (a) the wider insect population and (b) the
         beekeeping industry.

         Jonathan Shaw: A number of neonicotinoid pesticides are currently approved for use
         in the UK including: clothianidin, imidacloprid, thiacloprid, acetamiprid and

         The risks posed by products containing neonicotinoid pesticides to insects and bees
         were assessed as part of the authorisation process to which all pesticides are
         subjected before they are approved for use by Ministers.

         Laboratory studies indicate that these compounds have high toxicity to honeybees and
         other insects such as ladybirds, lacewings and some ground dwelling beetles.
         However, studies conducted under field conditions, using products containing these
         compounds in accordance with their approved conditions of use provide data which
         support the conclusion that the level of risk is acceptable.

         Field studies included monitoring impacts on honeybees confined to tents and exposed
         to flowering crops of maize, oilseed rape and sunflowers grown from seed treated with
         pesticides in excess of the UK approved application rate. No significant differences on
         bee behaviour or mortality were reported in treated and untreated crops.

8        Colony Collapse Disorder
In October 2010, the Independent reported on US research on colony collapse disorder:

         Now a team of researchers ...has completed an exhaustive survey of bees that bee
         keepers have managed to collect from collapsed colonies to see whether they are
         suffering from any unusual infections. Working with scientists at the US Army
         Edgewood Chemical Biological Centre in Maryland ...Professor Bromenshenk and his
         colleagues found that many of the bees were infected with both a virus, called
         invertebrate iridescent virus (IIV) and a fungus known as Nosema apis. (...) The
         scientists have yet to work out how the virus and fungus can interact, as neither seems
         to be particularly lethal on their own. However together they seem to be 100% fatal,
         the study suggests. 20

9        The effect of changes in land use
In October 2010, research from the Countryside Survey Partnership suggests that one cause
for the decline in pollinators is that certain wild plants have been out-competed by other

         Findings from a new scientific study, released today by the Countryside Survey
         Partnership, show that the total effect of changes to small patches of land over a
         number of years could be one of the factors in the decline of pollinating insects such as

         The analysis reveals that between 1990 and 2007 the number of wild plant species
         that provide nectar for bees has decreased, in small patches of semi natural habitat.
         These small but highly significant changes combine to make a total reduction in the
         areas supporting wild nectar providing plants that pollinators rely on.

     HC Deb 11 Jun 2008 c273W
     “Bio warfare scientists help solve mystery of dying bees”, Independent, 8 October 2010


          The report concludes that the decline is mainly due to nectar providing plants being
          crowded out by the growth of more competitive plant species. This overgrowth may be
          related to reduced management and air pollution where the deposition of nitrogenous
          compounds from the air acts like a fertilizer. In one habitat type - streamside margins -
          this reduced management has had benefits for freshwater quality, indicating the
          importance of not considering single ecosystem benefits in isolation.

          The Countryside Survey can be found at: 21

     Defra Press Release, New scientific study helps to reveal possible reasons for the decline of pollinators, 27
     October 2010


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