When you hear the statistic that one-third of the food we eat has been pollinated by bees, it becomes clear that for many years humans have vastly underestimated the importance of this insect to our survival.
Bees are the world’s number-one pollinator, responsible for the production of more than 90 crops and worth £191.8 million a year to the UK economy through crop pollination alone. A century ago, wild bees and other insects were also used for pollination but, as farming practices have changed, today the horticultural and agricultural industries are largely reliant on honeybees and beekeepers.
Yet something is rotten in the state of apiculture. Since late 2006 in the US, hive vanishings, referred to as Colony Collapse Disorder (CCD), have become increasingly commonplace and have caused the death of up to 70 per cent of honeybee hives.
Such levels of CCD have not hit the UK yet but, last year, nearly a third of the UK’s honeybee population was wiped out. Other pollinators such as wild bees, hoverflies and butterflies also appear to be in decline. With so many crops dependent on bees, such a serious population drop represents a tangible threat to food security and the economy.
And the situation is not restricted to honeybees. “At the same time, wild bumblebees, of which the UK once had 27 species, have been undergoing long-term declines driven by a loss of flowers from the countryside over the last 60 years,” says Professor Dave Goulson, head of the School of Biological & Environmental Sciences at the University of Stirling. “Two species have become extinct and several more may follow soon. Together, these bee declines are of great concern to farmers and horticulturalists. Without enough bees, crop yields will fall. We urgently need tofind sustainable ways to manage our pollinators.”
The issue has been in the media spotlight for some time now, grabbing plenty of column inches, while numerous radio and television reports, from Countryfile to Radio 4’s Farming Today programme, have allocated airspace to the topic. BBC4 even recently dedicated a whole hour to the cause in the documentary Who Killed the Honeybee?
The situation came to a head when hundreds of beekeepers descended on the Houses of Parliament in November 2008 to implore the government to take action on this potentially catastrophic issue.
Root causes
There are numerous schools of thought as to why bees have become so vulnerable in the last few years, but there is only one thing on which the experts do seem to agree - this phenomenon cannot be explained away by one singular cause.
The factors that have led to a global decline in honeybee populations are numerous and complex, with some specialists seeing a clear correlation between the health of the honeybee and the state of the world we live in.
The finger has been pointed at pesticides as being responsible for much of the problem, in particular a group of eight chemicals known as neonicotinoids.Although DEFRA secretary of state Hilary Benn has rejected calls from the Soil Association for the government to ban the use of neonicotinoids, in February The Co-operative became the first UK retailer to prohibit the use of the products on its own-brand fresh produce as part of a new 10-point plan to help reverse the decline in the bee population.
Simon Press, senior technical manager for The Co-op, explains how Plan Bee came into being. “Last spring, one of the group of eight neonicotinoids that we have now prohibited was applied to maize in the south-west of Germany and the region’s bee population was wiped out,” he tells FPJ. “Germany then immediately banned the use of neonicotinoids, which have been restricted for a number of years elsewhere in Europe.
“The Co-op then examined a lot of evidence, including studies done in Ghent and California, and found that low levels of neonicotinoids in pollen and crops can affect the eating and communication habits of bees.”
The Co-op divides pesticides into four categories - not restricted, monitored, prohibited and banned - and neonicotinoids have been declared prohibited. “This allows us to use a derogation if necessary,” says Press. “If a grower explains that they have no other option but to use neonicotinoids, then we will allow it for that season only.”
The usage of neonicotinoids will be restricted where possible - at least until they are shown to be safe. “Our prohibition is temporary,” says Press. “If we do research and find that the neonicotinoids are not affecting bees’ behaviour, then we will change their status to monitored. Pesticides are certainly not the sole reason, but they do affect the pollen-gathering and communication habits of honeybees.”
But Dr Julian Little, public and government affairs manager at crop protection company Bayer CropScience, warns about the dangers of embarking on a “witch hunt looking for the chemical fall guy”, rather than tackling the wide range of problems affecting bees.
“In the areas of France where they have banned the use of neonicotinoids, you would expect a vast improvement in bee health, but it is actually going through the floor even there,” he explains.
The same paradox applies in Australia, where farmers use neonicotinoids in their agricultural production, says Little, but which has one of the world’s healthiest bee populations.
One of the reasons that Australia still has a thriving bee population is because of the absence of varroa, a mite that lives on the surface of the bee and taps into its bloodstream, depriving it of vital nutrients and leaving it susceptible to other viruses and fungal diseases. “For example, the Nosema virus on its own won’t kill a bee, but if that bee has already been weakened by varroa, it will,” says Little.
“In the UK, we have had varroa for a long time but, until recently, we have been able to treat it using a Bayer product called Bayerol, which kills the varroa mite but not the actual bee,” says Little. “Unfortunately, the varroa mite became resistant to Bayerol so now there is a high level of the disease around and no major defence. Varroa is now endemic in the UK’s bee population.”
Bayer is continuously exploring new treatments for varroa and Little says he is “quite encouraged” by the new chemistry coming through. “But the ideal solution would be a bee with intrinsic resistance to varroa,” he adds.
Climate change has also been implicated, with pollinators less likely to forage in the wrong weather patterns and milder temperatures leading to greater incidence of fungal infections and other diseases in beehives.
Added to this, the loss of hedgerows and many of the elements of the landscape that were once vital sources of food for bees has been cited as a potential reason for their demise.
In the US, beehives are frequently moved around the country and this is also thought to have contributed to CCD, as transporting already weak bees can also make them even more susceptible to disease and parasites.
Seeking solutions
The efforts of the beekeepers who marched on Westminster and the other lobbying bodies that had worked to raise awareness of the plight of the bee at government level were rewarded in April, when DEFRA unveiled a £10m research fund to tackle bee and pollinator decline.
The move was welcomed by the beekeeping and agricultural industries, but there is a broad feeling that, in order for the cash injection to have any effect, any research must be well targeted.
The country’s universities and research institutions have already been actively working on the issue for some time now. The University of Sussex opened a new Laboratory of Apiculture and Social Insects in April, to conduct research into honeybees and other social insects such as ants, wasps and other bees.
Professor Francis Ratnieks, the UK’s only professor of apiculture, believes that a holistic approach to social insect work can help to resolve the problems facing honeybees and beekeepers. There are also four research projects on the go at the university specifically to do with honeybees, which form the Sussex Plan for Honeybee Heath and Wellbeing.
Ratnieks and his team are seeking to raise £1m for the Sussex Plan research projects. The first project is already underway and involves breeding bees that can keep hives clear of disease and pests. The next three projects will aim to: study how good the British countryside is for honeybees, decoding the communication dances made by forager bees to determine where worker bees are foraging; test and develop European and North American varroa control methods under British conditions and extend knowledge and good practice to beekeepers; and monitor hives for pathogens and other causes of death.
Under Plan Bee, The Co-op has donated £150,000 to study bee gene diversity and the effect of pesticides in conjunction with universities that have apiaries, such as the University of Sussex. Particular attention will be paid to UK farming practices, the impact of pesticides and the restricted gene pool that bees are derived from.
Some experts blame the decline in the UK honeybee population on beekeepers’ use of a foreign, poorly suited sub-species of honeybee from southern and eastern Europe and believe that a hardy native black variety (Apis mellifera mellifera) could hold the key to survival of the entire population.
The Co-op therefore unveiled a research fund to map locations of the native black honeybee, found only in a few remote parts of the country, and develop a breeding programme for the species. Over tens of thousands of years, the native black honeybee has evolved thick black hair and a larger body to help keep it warm in a cooler climate, and a shorter breeding season to reflect the UK summer.
At Kent research station East Malling Research (EMR), scientists are working with other UK researchers to bid for part of the government’s £10m fund.
Dr Michelle Fountain, an entomologist at EMR, is keen to see research progress as quickly as possible. “The way bees are managed in the US is quite different from the UK approach and, so far, the problems we are seeing with honeybees here are not as dramatic as on the other side of the Atlantic,” she says. “However, it is clear that our hives are being significantly weakened - probably as a result of a combination of complex factors, including a variety of pests and diseases, loss of important natural floral resources and the inappropriate use of pesticides.
“While honeybees are very important for crop pollination, we also need a greater understanding of other potential managed and wild bee pollinators.”
EMR is proposing to conduct research in conjunction with the University of Reading into alternative pollinators to honeybees, such as Mason bees, hoverflies and other bee species. “With top fruit, it is possible that we could exploit the use of solitary Mason bees with a system developed by Robin Dean of CJ Wildbird Foods, to enhance pollination in orchards,” says Fountain. “These bees are extremely effective at pollinating blossoms. We often see them in our own gardens in early spring, as they are more active early in the season than honeybees.
“Working in partnership with complementary specialists at other institutions, Dr Simon Potts, head of the pollination research group at the University of Reading, and Robin Dean, we can investigate ways of increasing the numbers of solitary bees and other naturally occurring pollinators in orchards in order to produce Class I fruit.
“Native bees thrive while pollinating our fruit trees but they need other sources of pollen nearby to sustain them through the summer months.
“By identifying more clearly the range of plants and habitats these insects require, we will be able to assist fruit growers to manage their hedgerows and broader landscapes to increase fruit pollination,” adds Fountain.
Some farmers have turned to buying commercial bumblebee nests from Europe and, for the last 20 years, these have been very widely used for tomato pollination in glasshouses all over the world.“Tomatoes require ‘buzz’ pollination, whereby the flower is vibrated to release the pollen; bumblebees are very good at this,” says Goulson. “Some farmers have also taken to using these bumblebee nests outdoors and in open-sided polytunnels,to boost pollination of soft and hard fruits. The problem is that these bees are not native; they originate in southern Europe. Importing them is costly, has a high carbon footprint and there is a risk of accidentally bringing inbee diseases that could infect our dwindling native bees.
“Interestingly, there is no hard evidence thatusing these commercial bumblebee nests in outdoor cropsactually increases yield; there might still be enough wild bees to go around. I am carrying out work to see whether this is so. If pollination of outdoor fruit crops really does need a boost, there are more environment-friendly ways of doing so other than buying in foreign bees, and these might actually also be cheaper.”
Goulson believes that the shortage of wild bumblebees is driven by a shortage of flowers, but he insists that this is easily remedied. “Flower strips can be sown either adjacent to crops or underneath fruit trees. Suitable seed mixes are readily available, and there are various options.For example, a 6x100m strip of the pretty annual flower Phacelia tanacetifolia will quickly attract many thousands of bumblebees to the farm.
“A more permanent solution is to sow awildflower seed mix; these just need an annual late-summer cut and will last for 10 years or more.
“Finally, a clover-rich pollen-and-nectar seed mix based on agricultural legumes is both cheap and will last for up to four years. Depending on the area, many of these options are supported by agri-environment schemes. The options just mentioned require a strip of land to be available near to the crop.
“For fruit trees, an alternative is to sow beneath and between the trees with a clover-rich mix. The nitrogen fixed by the clover will boost soil fertility, providing a double benefit to the crop,” says Goulson.
“Of course, these options all cost money but it need not be very much, and the benefits of the longer-lasting options remain for many years. Buying in commercial bee nests is also expensive (£50-100 per nest), and they only last for a few weeks. Boosting wild bee populations by providing additional flowers has the added environmental benefit of encouraging other beneficial and attractive insects such as hoverflies and butterflies.”
Agri-Nova Technology is launching a novel pheromone-based product, Pollinus, which aims to enhance and improve the performance of bees as crop pollinators. Based on a blend of four attractant pheromones, Pollinus is sprayed onto target crops by growers at the start of flowering and will attract honeybees and bumblebees into the crop to improve pollination.
Although new to the UK, Pollinus has been used successfully in France, Spain and Italy. Manufactured and developed by French firm Natural Plant Protection, the product has shown consistent benefits to growers of a wide range of pollination-sensitive crops.
“Growers want to improve the return they can get from bee pollinators,” says Clive Newitt of Agri-Nova Technology. “What Pollinus will do is to attract the bees that are active into the treated crop and so improve that return. It is particularly beneficial in cooler conditions by encouraging foraging.”
If the suggestion that bees do act as an indicator of the health of the planet is accurate, then it is clear that something needs to be done - and fast. There is evidently plenty of well-targeted work underway to address the issue - but can the government, research institutions and chemical companies come up with the right combination of solutions before it is too late? Only time will tell.
WHAT ARE WE GOING TO DO ABOUT BEE DECLINE?
First of all, we need to identify how bad the situation is - we know it is happening, but we are finding it difficult to quantify the impact for growers, writes Robin Dean of CJ Wildlife, who is also a commercial beekeeper and a post-graduate researcher with the University of Reading.
The EU-sponsored ALARM (Assessing LArge scale Risks for biodiversity with tested Methods) project has placed the reduction of pollinators at approximately 30 per cent over the last 10 years in places where data exists.A recent study conducted across the UK and the Netherlands has shown worrying reductions in both pollinators and plant diversity. This data, however, is patchy and there is real concern that the rates of decline are accelerating.
Currently, honey and bumblebees are receiving considerable media coverage, in particular the impact of pesticides on bee populations.It seems that the other 240-odd species of native bee have just been forgotten. In all honesty, honeybees are almost regarded as a domestic animal and supplies could be shipped in from abroad if they ever looked like disappearing completely from the shores of the UK.
By focusing only on the problems of honeybees, there is a real danger of losing perspective on the potential of some of the other bees, most of which are considerably more effective at pollination than honeybees.
Studies in the US on the Osmia family of solitary bees have indicated that they are at least 26 times more effective at viable pollen transfer than honeybees, with some species as much as 120 times more effective.
The commercial impact of a decline in pollinators is exceedingly difficult to quantify, but an example of possible consequences can be illustrated by the value of pollinators in agriculture - approximately $200 billion (£128.6bn) (Richards, 1993).Top- and soft-fruit crops are vulnerable, as good pollination has a direct impact on both yield and quality, and with apples may have a direct influence on both storage life and sugar content.
Kent-based top-fruit marketing desk Norman Collett is already one step ahead of the opposition, having participated in small-scale field trials to utilise the Red Mason Bee (Osmia rufa rufa) in a working orchard environment, pollinating both apples and cherries.Technical director Nigel Jenner said: “This is the most exciting development in optimising crop yield that we have seen for a long time.”
The Red Mason Bee is potentially the best candidate to supplement declining honeybee populations, with considerable work already having been done on the biology of the bee, propagation of captive populations and working delivery systems.
Certainly, the cherry trees in the orchard have seen the benefit of a specialised pollen-collecting bee, with fabulous crop synchronicity.This is probably the area where the greatest impact will be noticed, reducing the number of picking cycles, while increasing the yield overall.
One area that has to receive research attention in the near future is the fragile relationship between pollinators and the wider farming and growing environment. If you provide food sources, bees arrive from the wild, but how do you keep them there? Are there other potential managed pollinators besides honeybees and, if so, how do we harness their particular qualities? DEFRA has recently announced a substantial new fund for pollinator research but grower organisations need to ensure that the cash is appropriately targeted.
DEFRA’s higher and entry-level stewardship programmes currently encourage creation of pollen and nectar-rich areas, although the rules evolve constantly and specialist advice should be sought. But, grand aid aside, the environmental and agricultural benefits of encouraging diverse pollinator communities will also be reflected in better yields and quality of insect-pollinated fruit and vegetable crops.
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