permaculture

[Lawrence London <lfljvenaura@gmail.com>]

Pesticides linked to ‘large-scale population extinctions’ of wild bees
Insects play a key role in pollination of crops but many species are
believed to be in trouble
http://www.independent.co.uk/news/science/insecticides-bees-population-extinction-link-farmers-toxic-neonicotinoid-oilseed-rape-a7193951.html
A major 18-year study has found evidence linking controversial
"neonicotinoid" pesticides with “large-scale population extinctions” of
wild bees for the first time.
The insecticides have been shown to have “sub-lethal” effects on bees
<http://www.independent.co.uk/news/science/neonics-controversial-pesticide-affects-ability-of-bumblebees-to-pollinate-fruit-trees-a6739571.html>,
which are vital pollinators for many crops, in laboratory-style conditions
and small-scale studies.
But their actual effect in the real world was not well understood – until
now.
The use of neonicotinoids has been restricted by the European Union and
banned in some places, such as the US state of Maryland, because of growing
concern about their effects on bees.

   - Honey bees are being killed off in Europe by 57 different pesticides,
   study finds
   
<http://www.independent.co.uk/environment/nature/honeybees-decline-pesticides-study-a6925936.html>
   - Honeybees suffer learning difficulties after ingesting tiny quantities
   of pesticides, study finds
   
<http://www.independent.co.uk/news/science/honeybees-can-suffer-from-learning-and-memory-difficulties-after-ingesting-tiny-quantities-of-a6907346.html>
   - Neonics: Butterflies could also be affected by pesticide, says study
   
<http://www.independent.co.uk/environment/neonics-butterflies-could-also-be-affected-by-pesticide-says-study-a6747386.html>
   - Neonics: Controversial pesticide 'affects ability of bumblebees to
   pollinate fruit trees'
   
<http://www.independent.co.uk/news/science/neonics-controversial-pesticide-affects-ability-of-bumblebees-to-pollinate-fruit-trees-a6739571.html>

Last month the UK Government refused an application to use the pesticide –
by the National Farmers Union – for the second time this year, although it
has previously approved its use. However campaigners fear the restrictions
will be lifted after the UK leaves the EU.

The study looked at nearly 32,000 surveys of 62 wild bee species that were
carried out across much of England between 1994 and 2011 inclusive.

The researchers examined the effect of the first widespread use of
neonicotinoids as a treatment on oilseed rape seeds in 2002. This was
mainly designed to protect the crop from another insect, the cabbage stem
flea beetle.

But, writing in the journal *Nature
<http://www.nature.com/ncomms/index.html>,* the researchers concluded: “Our
results provide the first evidence that sub-lethal impacts of neonicotinoid
exposure can be linked to large-scale population extinctions of wild bee
species, with these effects being strongest for species that are known to
forage on oilseed rape crops.”

The researchers divided the countryside into five-kilometre squares, which
they classed as a “population” of bees, and looked at how they changed over
time.
<>

Long-term study links neonicotinoids to wild bee declines
http://www.reuters.com/article/us-science-bees-neonicotinoids-idUSKCN10R1M5

Wild bees that forage from oilseed rape crops treated with insecticides
known as neonicotinoids are more likely to undergo long-term population
declines than bees that forage from other sources, according to the
findings of an 18-year study.

The new research covered 62 species of bee found in the wild in Britain and
found a link between their shrinking populations and the use of
neonicotinoid pesticides.

Neonicotinoids are used worldwide in a range of crops and have been shown
in lab-based studies to be harmful to certain species of bee - notably
commercial honeybees and bumblebees.
<>

Neonic pesticide link to long-term wild bee decline
http://www.bbc.com/news/science-environment-37089385

The large-scale, long-term decline in wild bees across England has been
linked to the use of neonicotinoid insecticides by a new study.

Over 18 years, researchers analysed bees who forage heavily on oilseed
rape, a crop widely treated with "neonics".

The scientists attribute half of the total decline in wild bees to the use
of these chemicals.

Industry sources say the study shows an association, not a cause and effect.
Weighing the evidence

In recent years, several studies
<http://www.bbc.co.uk/news/science-environment-27980344>, conducted in the
lab and in the field, have identified a negative effect on honey bees and
bumble bees from the use of neonics.

But few researchers have looked at the long term impacts of these
substances.

This new paper examined the impacts on populations of 62 species of wild
bees across England over the period from 1994-2011.

The team, from the Centre for Ecology and Hydrology <http://www.ceh.ac.uk/>
(CEH), used distribution data on wild bees, excluding honey and bumblebees
collected by the bees, ants and wasps recording scheme
<http://www.bwars.com/>.

They were able to compare the locations of these bees and their changing
populations with growing patterns of oilseed rape across England over 18
years.

The amount of this crop being sown has increased significantly over the
period of the study, from around 500,000 hectares in 1994 to over 700,000
in 2011.

A key innovation was the commercial licensing of neonicotinoid insecticides
for the crop in the UK in 2002. Seeds are coated with the chemical and
every part of the plant becomes toxic to pests.

Manufacturers hailed the development as a major advance, reducing the need
for leaf spraying with other insecticides. Around 85% of the oilseed rape
crop in England now uses this method for pest protection.
'Long term, large scale'

But this new work suggests, for the first time, that the detrimental
impacts seen in the lab can be linked to large scale population extinctions
of wild bees, especially for those species of bees that spend longer
foraging on oilseed rape.

"The negative effects that have been reported previously do scale up to
long-term, large-scale multi-species impacts that are harmful," said Dr
Nick Isaac, a co-author of the new paper.

"Neonicotinoids are harmful, we can be very confident about that and our
mean correlation is three times more negative for foragers than for
non-foragers."

There was a decline in the number of populations of 10%, attributable to
neonicotinoids, across the 34 species that forage on oilseed rape. Five of
the species showed declines of 20% or more, with the worst affected
declining by 30%. Overall, half the total decline in wild bees could be
linked to the chemicals.

"Historically, if you just have oilseed rape, many bees tend to benefit
from that because it is this enormous foraging resource all over the
countryside," said lead author Dr Ben Woodcock from the CEH.

"But this co-relation study suggests that once its treated with
neonicotinoids up to 85%, then they are starting to be exposed and it's
starting to have these detrimental impacts on them."

"What we can't say is what these detrimental impacts are but what it does
suggest is you can have these population declines and they can be big - I
mean 30% is a big decline."

The authors acknowledge that their study finds an association and doesn't
prove a cause and effect link between the use of neonicotinoids and the
decline of bee populations.
Intensive farming at fault?

The manufacturers of the chemicals agree that it is an interesting
statistical study, but they argue that intensive farming and not just a
single insecticide might be the real cause of the decline.

"Since most of the oilseed rape grown in the UK was treated with a
neonicotinoid seed treatment during the years that this study looked at, we
believe its findings would be more correctly headlined that intensive
agriculture is causing some issues with pollinators," said Dr Julian
Little, from Bayer Crop Science in the UK.

"Whether this is due to the use of insecticides is not clear; a lack of
nesting sites and pollen and nectar sources in these areas may also be
critical factors."

Other scientists, though, believe that the new study is some of the
strongest data yet for the impact of these substances over the long term.

"This is the first good evidence that bees are affected at the population
level by the widespread use of neonicotinoids," said Prof Henrik Smith from
Lund University in Sweden, who was not involved with the research.

"It is the combination of evidence that is persuasive, that the effect
depends on neonicotinoid exposure and affect species known to forage on
oilseed rape more than other species."

The European Food Safety Authority is currently conducting a review of the
scientific evidence about neonicotinoids.

An EU-wide moratorium <http://www.bbc.co.uk/news/world-europe-22335520> on
their use was implemented in 2013 and is still in place. This new work is
likely to be part of that review, along with another, major field study due
out in the Autumn. However, the National Farmers Union (NFU) say that it
doesn't make a convincing case about the extinction of bees in England.

"While this study claims to provide an important contribution to the
evidence base underpinning the current EU moratorium on some uses of
neonicotinoids, experts reviewing all the evidence have concluded that
there are still major gaps in our knowledge and a limited evidence base to
guide policymakers," said Dr Chris Hartfield from the NFU.

The scientists involved in the wild bee study caution against "simplistic
solutions" to the problems of pollinators. They say a "holistic" approach
to the use of insecticides must be taken and they are lukewarm about the
idea of banning chemicals.

"When you grow oilseed rape you can't do it without pesticides, there's an
underlying reality to this," said Dr Woodcock.

"Just because you say 'don't use neonicotinoids anymore', the likelihood is
that another pesticide is going to have to be used to compensate for that,
that is going to have impacts on runoffs into waterways and on other
species that you can control for."

"It needs to be taken in a very holistic perspective, you can't just say as
long as we can save the bees everything else can go to hell, that's not
where you want to be at."

The study has been published
<http://nature.com/articles/doi:10.1038/ncomms12459> in the journal Nature
Communications.