Give
Bees a chance
Pat Thomas 11/02/2008
Recent>http://
Recent>www.theecologist.org/pages/archive_detail.asp?content_id=1170
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...
Mobile colonies
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.
Overcrowding
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.
Unnatural diets
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.
Parasites
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
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 crops
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.
Electromagnetic fields
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 The>www.rhs.org.uk
The Bumblebee Pages Bumblebee>www.bumblebee.org
Bumblebee Conservation Trust What>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.