COLONY COLLAPSE DISORDER
spectre
http://www.ento.psu.edu/MAAREC/pressReleases/ColonyCollapseDisorderWG.html
http://www.ento.psu.edu/MAAREC/pressReleases/CCDMap07FebRev1-.jpg
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http://news.independent.co.uk/environment/wildlife/article2314202.ece
Species Under Threat
Across America, millions of honey bees are abandoning their hives and
flying off to die, leaving beekeepers facing ruin and US agriculture
under threat. And to date, no one knows why.
BY Michael McCarthy
It has echoes of a murder mystery in polite society. There could
hardly be a more sedate and unruffled world than beekeeping, but the
beekeepers of the United States have suddenly encountered affliction,
calamity and death on a massive scale. And they have not got a clue
why it is happening.
Across the country, from the Atlantic coast to the Pacific, honey bee
colonies have started to die off, abruptly and decisively. Millions of
bees are abandoning their hives and flying off to die (they cannot
survive as a colony without the queen, who is always left behind).
Some beekeepers, especially those with big portable apiaries, or bee
farms, which are used for large-scale pollination of fruit and
vegetable crops, are facing commercial ruin - and there is a growing
threat that America's agriculture may be struck a mortal blow by the
loss of the pollinators. Yet scientists investigating the problem have
no idea what is causing it.
The phenomenon is recent, dating back to autumn, when beekeepers along
the east coast of the US started to notice the die-offs. It was given
the name of fall dwindle disease, but now it has been renamed to
reflect better its dramatic nature, and is known as colony collapse
disorder.
It is swift in its effect. Over the course of a week the majority of
the bees in an affected colony will flee the hive and disappear, going
off to die elsewhere. The few remaining insects are then found to be
enormously diseased - they have a "tremendous pathogen load", the
scientists say. But why? No one yet knows.
The condition has been recorded in at least 24 states. It is having a
major effect on the mobile apiaries which are transported across the
US to pollinate large-scale crops, such as oranges in Florida or
almonds in California. Some have lost up to 90 per cent of their bees.
A reliable estimate of the true extent of the problem will not be
possible for another month or so, until winter comes to an end and the
hibernating bee colonies in the northern American states wake up. But
scientists are very worried, not least because, as there is no obvious
cause for the disease as yet, there is no way of tackling it.
"We are extremely alarmed," said Diana Cox-Foster, the professor of
Entomology at Penn States University and one of the leading members of
a specially convened colony-collapse disorder working group.
"It is one of the most alarming insect diseases ever to hit the US and
it has the potential to devastate the US beekeeping industry. In some
ways it may be to the insect world what foot-and-mouth disease was to
livestock in England."
Most of the pollination for more than 90 commercial crops grown
throughout the United States is provided byApis mellifera, the honey
bee, and the value from the pollination to agricultural output in the
country is estimated at $14.6bn (£8bn) annually. Growers rent about
1.5 million colonies each year to pollinate crops - a colony usually
being the group of bees in a hive.
California's almond crop, which is the biggest in the world,
stretching over more than half a million acres over the state's
central valley, now draws more than half of the mobile bee colonies in
America at pollinating time - which is now. Some big commercial
beekeeping operations which have been hit hard by the current disease
have had to import millions of bees from Australia to enable the
almond trees to be pollinated.
Some of these mobile apiaries have been losing 60 or 70 per cent of
their insects, or even more. "A honey producer in Pennsylvania doing
local pollination, Larry Curtis, has gone from 1,000 bee colonies to
fewer than eight," said Professor Cox-Foster. The disease showed a
completely new set of symptoms, "which does not seem to match anything
in the literature", said the entomologist.
One was that the bees left the hive and flew away to die elsewhere,
over about a week. Another was that the few bees left inside the hive
were carrying "a tremendous number of pathogens" - virtually every
known bee virus could be detected in the insects, she said, and some
bees were carrying five or six viruses at a time, as well as fungal
infections. Because of this it was assumed that the bees' immune
systems were being suppressed in some way.
Professor Cox-Foster went on: "And another unusual symptom that we're
are seeing, which makes this very different, is that normally when a
bee colony gets weak and its numbers are decreasing, other
neighbouring bees will come and steal the resources - they will take
away the honey and the pollen.
"Other insects like to take advantage too, such as the wax moth or the
hive beetle. But none of this is happening. These insects are not
coming in.
"This suggests that there is something toxic in the colony itself
which is repelling them."
The scientists involved in the working group were surveying the dead
colonies but did not think the cause of the deaths was anything
brought in by beekeepers, such as pesticides, she said.
Another of the researchers studying the collapses, Dennis van
Engelsdorp, a bee specialist with the State of Pennsylvania, said it
was still difficult to gauge their full extent. It was possible that
the bees were fleeing the colonies because they sensed they themselves
were diseased or affected in some way, he said. This behaviour has
been recorded in other social insects, such as ants.
The introduction of the parasitic bee mite Varroa in 1987 and the
invasion of the Africanised honey bee in 1990 have threatened honey
bee colonies in the US and in other parts of the world, but although
serious, they were easily comprehensible; colony collapse disorder is
a deep mystery.
One theory is that the bees may be suffering from stress as beekeepers
increasingly transport them around the country, the hives stacked on
top of each other on the backs of trucks, to carry out pollination
contracts in orchard after orchard, in different states.
Tens of billions of bees are now involved in this "migratory"
pollination. An operator might go from pollinating oranges in Florida,
to apples in Pennsylvania, to blueberries in Maine, then back to
Massachusetts to pollinate cranberries.
The business is so big that pollination is replacing honey-making as
the main money earner at the top end of the beekeeping market, not
least because in recent years the US has been flooded with cheap honey
imports, mainly from Argentina and China.
A typical bee colony, which might be anything from 15,000 to 30,000
bees, would be rented out to a fruit grower for about $135 - a price
that is up from $55 only three years ago. To keep the bees' energy up
while they are pollinating, beekeepers feed them protein supplements
and syrup carried around in large tanks.
It is in these migratory colonies where the biggest losses have been
seen. But the stress theory is as much speculation as anything else.
At the moment, the disappearance of America's bees is as big a mystery
as the disappearance of London's sparrows.
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http://www.organicconsumers.org/articles/article_4557.cfm
http://beealert.blackfoot.net/~beealert/surveys/index.php
http://www.ebeehoney.com/Pollination.html