permaculture

[Lawrence London <lfljvenaura@gmail.com>]

Monsanto's global weedkiller harms honeybees, research finds | Environment
| The Guardian
https://www.theguardian.com/environment/2018/sep/24/monsanto-weedkiller-harms-bees-research-finds
Monsanto's global weedkiller harms honeybees, research finds
Glyphosate – the most used pesticide ever – damages the good bacteria in
honeybee guts, making them more prone to deadly infections
Bees in a study marked with non-toxic paint. Photograph: Vivian
Abagiu/College of Natural Sciences/UT Austin

The world’s most used weedkiller damages the beneficial bacteria in the
guts of honeybees and makes them more prone to deadly infections, new
research has found.

Previous studies have shown that pesticides such as neonicotinoids
<https://www.theguardian.com/environment/2017/jun/29/pesticides-damage-survival-of-bee-colonies-landmark-study-shows>
cause harm to bees, whose pollination is vital to about three-quarters of
all food crops. Glyphosate, manufactured by Monsanto, targets an enzyme
only found in plants and bacteria.

However, the new study shows that glyphosate damages the microbiota that
honeybees need to grow and to fight off pathogens. The findings show
glyphosate, the most used agricultural chemical ever
<https://www.newsweek.com/glyphosate-now-most-used-agricultural-chemical-ever-422419>,
may be contributing to the global decline in bees, along with the loss of
habitat.

“We demonstrated that the abundances of dominant gut microbiota species are
decreased in bees exposed to glyphosate at concentrations documented in the
environment,” said Erick Motta and colleagues from University of Texas at
Austin in their new paper. They found that young worker bees exposed to
glyphosate exposure died more often when later exposed to a common
bacterium.

Other research, from China and published in July, showed that honeybee
larvae grew more slowly and died more often
<https://pubs.acs.org/doi/abs/10.1021/acs.jafc.8b02212> when exposed to
glyphosate. An earlier study, in 2015
<http://jeb.biologists.org/content/218/17/2799>, showed the exposure of
adult bees to the herbicide at levels found in fields “impairs the
cognitive capacities needed for a successful return to the hive”.

“The biggest impact of glyphosate on bees is the destruction of the
wildflowers on which they depend,” said Matt Sharlow, at conservation group
Buglife. “Evidence to date suggests direct toxicity to bees is fairly low,
however the new study clearly demonstrates that pesticide use can have
significant unintended consequences.”

Prof Dave Goulson, at the University of Sussex, said: “It now seems that we
have to add glyphosate to the list of problems that bees face. This study
is also further evidence that the landscape-scale application of large
quantities of pesticides has negative consequences that are often hard to
predict.”
Assumed safety of pesticide use is false, says top government scientist
Read more

However, Oliver Jones, a chemist at RMIT University in Melbourne,
Australia, said: “To my mind the doses of glyphosate used were rather high.
The paper shows only that glyphosate can potentially interfere with the
bacteria in the bee gut, not that it actually does so in the environment.”

A spokesman for Monsanto <https://www.theguardian.com/business/monsanto>
said: “Claims that glyphosate has a negative impact on honey bees are
simply not true. No large-scale study has found any link between glyphosate
and the decline of the honeybee population. More than 40 years of robust,
independent scientific evidence shows that it poses no unreasonable risk
for humans, animal, and the environment generally.”

The new research, published in the Proceedings of the National Academy of
Sciences <http://www.pnas.org/cgi/doi/10.1073/pnas.1803880115>, found that
some of the key beneficial bacteria in bees’ guts have the enzyme that is
targeted by glyphosate. It also found that the ability of newly emerged
worker bees to develop a normal gut biome was hampered by glyphosate
exposure.
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Harm to gut bacteria by glyphosate exposure has also been shown in a pilot
study in rats
<https://www.theguardian.com/environment/2018/may/16/glyphosate-shown-to-disrupt-microbiome-at-safe-levels-study-claims>.
“Gut bacteria play a vital role in maintaining good health, in organisms as
diverse as bees and humans,” said Goulson. “The finding that these bacteria
are sensitive to the most widely used pesticide in the world is thus
concerning.”

People are known to widely consume glyphosate residues
<https://jamanetwork.com/journals/jama/fullarticle/2658306> in food - such
as children’s breakfast cereal
<https://www.theguardian.com/environment/2018/aug/16/weedkiller-cereal-monsanto-roundup-childrens-food>
- but the health impact is controversial. In August a US court ordered 
Monsanto
to pay $289m in damages
<https://www.theguardian.com/business/2018/aug/10/monsanto-trial-cancer-dewayne-johnson-ruling>
after a jury ruled that the weedkiller caused a terminally ill man’s
cancer. The company filed papers to dismiss the case
<https://www.reuters.com/article/us-bayer-glyphosate-lawsuits/bayers-monsanto-asks-us-court-to-toss-289-million-glyphosate-verdict-idUSKCN1LZ0H7>
on 19 September.

The weedkiller, sold as Roundup, won a shortened five-year lease in the EU
in 2017. In 2015
<https://www.theguardian.com/environment/2015/mar/21/roundup-cancer-who-glyphosate->,
the World Health Organisation’s cancer agency, the IARC, declared
glyphosate “probably carcinogenic to humans,” although several
international agencies
<https://www.theguardian.com/environment/2016/may/16/glyphosate-unlikely-to-pose-risk-to-humans-unwho-study-says>
subsequently came to opposite conclusions. Monsanto insists glyphosate is
safe.