Are the bees still
disappearing, and if so do we know why and do we have a solution?
—David, Grand
Rapids, MI
The topic of disappearing honey bees
first cropped up in 2004 and by the spring of 2007 was all over the
news.
Thousands of commercial beekeepers
across the U.S. and beyond were reporting in some cases that as many
as two-thirds of their honey bees were flying away from their hives,
never to return.
What made the problem—dubbed
“Colony Collapse Disorder” (CCD)—so unusual is that most
traumas to bee colonies leaves bees dead in or around their hives,
not mysteriously gone altogether.
Strangely enough, there was
no concrete evidence pointing to disease or predation or of mites
that tend to attack bee hives.
Some beekeepers reported that moths,
animals and other bees were steering clear of the newly empty nests,
leading to speculation that chemical contamination due to widespread
use of pesticides might be to blame.
But no smoking gun emerged and the
mystery remains today.
According to the U.S. Department of
Agriculture’s Agricultural Research Service (ARS), which last year
convened a multi-agency steering committee to assess the problem and
find solutions, several factors could be combining to cause CCD.
“Pesticides may be having
unexpected negative effects on honey bees,” reports ARS, adding
that as yet unknown parasites, pathogens or viruses could also be
wreaking havoc on bee colonies.
Studies have also indicated that
poor management of populations of commercial honey bees—including
inadequate diet and long distance transportation—may play a
role.
In one study, researchers from Columbia University
isolated the presence of a virus—the so-called Israeli Acute
Paralysis Virus—in upwards of 96 percent of the hives studied that
were affected by CCD.
Other studies point to widespread
use of Imidacloprid, a common grub-control chemical used on lawns
and farms and which has already been banned in France due to its
alleged effect on bees.
But finding a single cause of CCD
seems unlikely, and ARS researchers point to the possibility of “a
perfect storm of existing stresses” weakening colonies to the
point of collapse:
“Stress…compromises the immune
system of bees…and may disrupt their social system, making
colonies more susceptible to disease.”
Whatever the cause,
CCD remains a real threat to agriculture.
About a third of all American farm
production is dependent upon the pollination efforts of
commercially-raised honey bees.
While diversifying the stock of
insect pollinators beyond just one species of honey bee would
certainly represent a step in the right direction, re-jiggering the
nation’s agricultural system represents no small challenge.
Not
surprisingly perhaps, organic beekeepers have not experienced CCD,
leading to speculation that overall greener management practices
could be the answer even if direct causes are not determined.
Meanwhile, efforts to genetically
modify bees that are resistant to predators and pathogens could also
prove fruitful, although such high tech solutions are still untested
and could open up other cans of worms.
CONTACTS:
USDA Agricultural Research Service, www.ars, usda.gov;
CCD Steering Committee Q&A;
www.ars.usda.gov/is/br/ccd.
