Give Bees a chance
11th February, 2008
Recent reports of catastrophic declines in bee populations have had scientists buzzing around looking for a plausible explanation. Is it mites? Is it GM crops? Is it mobile phones or habitat loss? It's all of these things, says Pat Thomas, but it's also so much more than that.
Forget everything you thought you knew about the sedate and rarefied world of beekeeping. Bees are big business. In 2006, a Cornell University study found that in the USA, bees annually pollinate more than $14 billion worth of seed and crops - mostly fruits, vegetables and nuts. In the UK they are responsible for the pollination of around £200 million worth of food crops.
Bees' role in the natural order of our world is crucial and their importance as pollinators, both for agriculture and for wild plants, can't be underestimated. Nor can it simply be quantified in monetary terms. Bees are what is known as a keystone species, ensuring the continued reproduction and survival not only of plants but other organisms that depend on those plants for survival. Once a keystone species disappears, other species begin to disappear too - thus Albert Einstein's apocalyptic and, these days, oft-quoted view: 'If the bee disappeared off the surface of the globe, then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.'
This vision may be coming true. Our bees are dying. In record numbers. The recent disappearance of catastrophic numbers of bees from their colonies, in the USA especially but also in Europe, has been dubbed Colony Collapse Disorder (CCD). The most striking symptom of CCD is that the bees appear to die away from the hive. One day they fly away and never return. Those few that are left behind, say scientists, are very ill indeed. Virtually every known bee virus can be found in their bodies; some are carrying five or six viruses, as well as several fungal infections, at the same time. The other worrying factor is the way that other bees and insects avoid these abandoned nests. In nature, nothing is wasted and an abandoned hive would normally be taken over by other creatures opportunistically looking for food and shelter. But hives suffering CCD remain empty, suggesting that there may be something toxic in the colony itself.
At one time, a 10 per cent loss over a season was considered normal; when parasitic mites became a common problem that number rose to around 30 per cent. With CCD, average colony losses have been reported at around 70 to 80 per cent.
Huge numbers of theories abound as to why the bees are dying, but so far no single one explains why, or provides a clue about how to remedy the situation. Perhaps our search for the cause is too narrow, however. If we want to understand why our bees are dying off, then a useful first step would be to examine the myriad ways we have exploited them and corrupted their natural behaviour for our own convenience...
As the number of crops we grow increases, the need for pollinators grows too, and these days beekeepers can make more money renting out bees to pollinate food crops than they ever could selling home-made honey. Migratory pollination is a multi-billion-dollar industry. But transporting bees huge distances in giant 18-wheel juggernauts with the hives stacked on top of each other, also stresses the insects out. Higher levels of stress in turn make them more vulnerable to disease. Studies show that CCD is most prevalent in transported bees, with losses of up to 90 per cent of the colony.
By transporting bees across great distances, beekeepers are also transporting mites and any other parasites, viruses, bacteria and fungi, to places it might not otherwise have spread to.
Industrial-size colonies may have a bigger market value but they also bring the same problems to bees that industrial poultry farmers have visited on their chickens and turkeys: the easy spread of disease. In March of this year, a survey of Ohio beekeepers found that the average loss of live colonies in the previous six months was 72 per cent. A close look at the figures, however, revealed that beekeepers with fewer than 100 colonies had an average 55 per cent loss, but the loss rose to 75 per cent for those with 500 or more colonies. In addition, the boxy structure of modern commercial hives, which makes it easier to squeeze several colonies into a small space, and the configuration of bee yards, have largely been designed for the convenience of human beekeepers and not necessarily with the health and natural biology of the bees in mind.
The natural diet of a bee is pollen and honey - a mixture rich in enzymes, antioxidants and other health supporting nutrients. But to beef their bees up for the heavy work of pollination, commercial beekeepers feed them on the bee equivalent of protein bars and Lucozade - a mixture of artificial supplements, protein and glucose/fructose syrup. These sticky mixtures are freighted around the country in tankers to wherever the colonies happen to be. It's expensive and occasionally it proves cheaper to kill off whole colonies rather than feed them over the winter.
The artificial diets are in part a response to the decline of the bees' natural forage areas. Fewer plants means less natural food for the bees. But taking any living creature off its natural diet and force-feeding it junk food will inevitably result in poor immunity. Bees in particular have a much less adaptive immune system than we do, so if a bee becomes infected with a virus, its body can't respond by making specific antibodies.
Intensive bee farming
In a normal colony the queen can live and produce eggs for several years. In commercial beekeeping, breeding better queens is a profitable business and queens are regularly killed and replaced - sometimes as often as every six months. The queen is often subjected to the stress of having her wings clipped to identify her and also to temporarily prevent 'swarming' - when bees leave one colony, with a new queen and form another one elsewhere (this is the natural way for bees to ensure their survival and genetic diversity).
To ensure that colonies express the genetic qualities that beekeepers value, however, some virgin queens are artificially inseminated with sperm from crushed males. This practice, while not universal, is gaining in popularity as it becomes more difficult for honeybees to survive naturally.
Bee populations have been affected by two types of mite infestations in recent years: a tracheal mite and the varroa mite that attacks the intestines. Varroa, in particular, depresses the bees' immune response, making it more prone to infection. Varroa also makes the bees more vulnerable to a crippling viral disease that produces wing deformity. These viruses can be spread from bee to bee but are also passed on from the queen to her brood.
In a healthy colony, varroa could to some degree be seen as useful, helping to cull the weaker members. But in already weakened artificial colonies we treat the infestation with insecticides such as coumaphos, a dangerous organophosphate to which mites rapidly develop resistance. This resistance can be passed on from generation to generation, and some evidence suggests that resistant mites actually thrive with repeated exposure. Likewise, fluvalinate creates resistance in the mite and disrupts the bees' feeding behaviour and ability to navigate. A bee that can't find its way back home will eventually die.
Pesticides used on food crops and other crops can affect bees, even at sub-lethal doses. Exposure can produce a kind of pesticide intoxication that makes the bees appear 'drunk', disrupts navigation, feeding behaviour, memory, learning and egg laying.
Fipronil, for example, impairs the olfactory memory process - which honeybees use to find pollen and nectar. Spinosad can make bumblebees slower foragers even at low doses. The insecticide imidacloprid can cause bees to forget where their hives are located. The French government banned imidacloprin in 1999 due to its toxicity to bees, the effects of which French beekeepers labelled 'mad bee disease'.
GM plants account for around 40 per cent of US cornfields. A small study from the University of Jena in Germany found that pollen from Bt corn made the bees more vulnerable to death as a result of carrying the varroa mite. The bacterial toxin in the GM corn appeared to alter the surface of the bees' intestines, weakening them enough to allow the parasites to gain entry.
Bees can be exposed to GM in other ways - for instance, when they are fed supplements produced from GM crops such as high-fructose corn syrup. The effects of such a diet have never been studied.
As stories of CCD became more prominent, other theories have emerged. Mobile phones and overhead power lines have been blamed for interfering with bees' homing radar and preventing them from getting back to their colonies. It is not clear how sound this theory is. However, what is more well known is that high background levels of electromagnetic radiation can suppress immune response and disrupt the nervous system in a variety of living creatures. It is unlikely that bees are the exception to the rule.
Is it our fault?
Having been co-opted into industrial farming, commercial bees have become just another type of farm machinery. But the machinery is breaking down. Ironically, the giant farms that destroy natural habitats and use large quantities of pesticides are the ones that need bees the most, and are at the same time important contributors to their decline.
As far back as 1923, the philosopher and scholar Rudolf Steiner predicted that commercial beekeeping would wipe out bees within 100 years. Was he right?
Bees are sensitive, social creatures that have achieved a high degree of harmony and productivity in their colonies (each of which can house up to 60,000 individual bees). Their social structure is both productive and ordered. They are intelligent - and become more so with age. They learn and remember; they can use visual orientation to accurately estimate the distance from a nectar source while in flight. They construct colonies that are warm in the winter and cool in the summer. They also suffer from occupational diseases, just like we do.
The single coherent thread that connects all the various theories of CCD is a massive failure of these creatures' immune systems. It is entirely possible that CCD is the inevitable result of a overwhelming, ongoing assault on these creatures' delicate immune systems.
Humans have had a symbolic relationship with bees since they were first domesticated 7,000 years ago, but it is clearly not a relationship of equals.
We have long exploited bees for our own ends, even when we didn't really need to. Their use in oilseed rape is a good example. Oilseed rape plants are normally pollinated by the wind. However, by bringing bees into the field, yields can be increased by up to 20 per cent.
Because of our close proximity to bees and our deep reliance on them, any problems in our society, in the way we think and act, in our broader relationship with nature, will also affect theirs. The collapse of the bee population isn't just a scientific riddle to be solved with more and better science and technology. It could be a frightening vision of our own future.
Bees in the 'hood
Of the 256 native bee species in the UK, 25 per cent are now listed as endangered. Because of the loss of floral diversity and nest sites, due to intensive modern agriculture, domestic gardens are now the principal habitat for many species of wild bee. Why not get together with your neighbours and make your neighbourhood bee-friendly?
Information from the following organisations can help you make your gardens irresistible to bees:
Royal Horticultural Society www.rhs.org.uk
The Bumblebee Pages www.bumblebee.org
Bumblebee Conservation Trust www.bumblebeeconservationtrust.co.uk
What needs to happen next?
Defra spends just over a million pounds a year on bee health and welfare, through the National Bee Unit (NBU) at York. Of this, only around £180,000 is spent on research and this figure has been steadily declining over the past six years.
The NBU is charged with monitoring bee losses. Yet, even though some British beekeepers have reported dramatic colony losses of up to 90 per cent this year, Defra insists that no definite conclusions can be reached.
The US Department of Agriculture has responded more decisively, with a special study group to understand more about CCD. Its mandate is to focus on stress caused by transport, disease levels, husbandry, pesticide use and natural toxins found in plants, as well as the ability of beekeepers to spot disease in their hives.
How great does the loss have to be, and how long does it have to go on, before we also take action? Defra must take the plight of our bees seriously and direct substantial funds towards research that helps us understand why our bees are dying and what we can do about it.
This article first appeared in the Ecologist June 2007
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