I posted on this topic four years
ago and we had plenty of evidence then that is why these insecticides were
withdrawn in France
and actually I believe from much of the EU.
It obviously has not gotten better and losing a third of the apiaries
per year is no longer a short term or sporadic effect. It is the natural result of toxin
accumulation.
The insanity is that Bayer is not
making enough with this product line that withdrawing it matters much. The real
cost is that it would immediately give credence to the resultant class action
suit and generate billions in claims.
The government made a mistake and
the government needs to suspend the product to get everyone off the pointy end.
Operators are now pretty well
onto the source of the problem and were they can they are avoiding areas of
usage. Unfortunately, that is not good
enough if we are losing a third of our colonies every year.
In the meantime an army of well
rewarded researchers chirp in with claims that the science is not certain. This is an insult to the least informed individual
and a mere coverup.
Honeybee deaths linked to seed insecticide exposure
by Brian Wallheimer for Purdue News
Honeybee populations have been in serious decline for years, and Purdue University
scientists may have identified one of the factors that cause bee deaths around
agricultural fields.
Analyses of bees found dead in and around hives from several
apiaries over two years in Indiana showed the presence of neonicotinoid
insecticides, which are commonly used to coat corn and soybean seeds before
planting. The research showed that those insecticides were present at high
concentrations in waste talc that is exhausted from farm machinery during
planting.
The insecticides clothianidin and thiamethoxam were also
consistently found at low levels in soil - up to two years after treated seed
was planted - on nearby dandelion flowers and in corn pollen gathered by the
bees, according to the findings released in the journal PLoS One this
month.
"We know that these insecticides are highly toxic to bees; we
found them in each sample of dead and dying bees," said Christian Krupke,
associate professor of entomology and a co-author of the findings.
The United States
is losing about one-third of its honeybee hives each year, according to Greg Hunt, a Purdue professor of
behavioral genetics, honeybee specialist and co-author of the findings. Hunt
said no one factor is to blame, though scientists believe that others such as
mites and insecticides are all working against the bees, which are important
for pollinating food crops and
wild plants.
"It's like death by a thousand cuts for these bees," Hunt
said.
Krupke and Hunt received reports that bee deaths in 2010 and 2011 were
occurring at planting time in hives near agricultural fields. Toxicological
screenings performed by Brian Eitzer, a co-author of the study from
the Connecticut Agricultural Experiment Station, for an array of pesticides
showed that the neonicotinoids used to treat corn and soybean seed were present
in each sample of affected bees. Krupke said other bees at those hives
exhibited tremors, uncoordinated movement and convulsions, all signs of
insecticide poisoning.
Seeds of most annual crops are coated in neonicotinoid insecticides for
protection after planting. All corn seed and about half of all soybean seed is
treated. The coatings are sticky, and in order to keep seeds flowing freely in
the vacuum systems used
in planters, they are mixed with talc. Excess talc used in the process is
released during planting and routine planter cleaning procedures.
"Given the rates of corn planting and talc usage, we are blowing
large amounts of contaminated talc into the environment. The dust is quite
light and appears to be quite mobile," Krupke said.
Krupke said the corn pollen that bees were bringing back to hives later
in the year tested positive for neonicotinoids at levels roughly below 100
parts per billion.
"That's enough to kill bees if sufficient amounts are consumed,
but it is not acutely toxic," he said.
On the other hand, the exhausted talc showed extremely high levels of
the insecticides - up to about 700,000 times the lethal contact dose for a bee.
"Whatever was on the seed was being exhausted into the
environment," Krupke said.
"This material is so
concentrated that even small amounts landing on flowering plants around a field
can kill foragers or be transported to the hive in contaminated pollen. This might
be why we found these insecticides in pollen that the bees had collected and
brought back to their hives."
Krupke suggested that efforts could be made to limit or eliminate talc
emissions during planting.
"That's the first target for corrective action," he said.
"It stands out as being an enormous source of potential environmental
contamination, not just for honeybees, but for any insects living in or near
these fields. The fact that these compounds can persist for months or years
means that plants growing in these soils can take up these compounds in leaf
tissue or pollen."
Although corn and soybean production does not require insect
pollinators, that is not the case for most plants that provide food. Krupke
said protecting bees benefits agriculture since most fruit, nut and
vegetable crop plants
depend upon honeybees for pollination. The U.S. Department of Agriculture
estimates the value of honeybees to commercial agriculture at $15 billion to
$20 billion annually.
Hunt said he would continue to study the sublethal effects of
neonicotinoids. He said for bees that do not die from the insecticide there
could be other effects, such as loss of homing ability or less resistance
to disease or
mites.
"I think we need to stop and try to understand the risks
associated with these insecticides," Hunt said.
The North American Pollinator Protection Campaign and the USDA's
Agriculture and Food Research Initiative funded the research.
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