Pesticides
affect ‘far more species’ of bees, says study
UK
study links population decline to increase use of neonicotinoids in
oilseed rape cultivation
yesterday
by: Pilita Clark,
Environment Correspondent
New research
suggests that a family of pesticides has cut the presence of wild
bees in the English countryside by as much as 30 per cent over the
past decade as the use of the chemicals in oilseed rape crops has
surged.
FT View
In defence of bees
The health of bees
is not just a popular campaigning issue for environmental
non-governmental organisations and wildlife enthusiasts. It is also
crucial to the global food supply.
Neonicotinoids,
chemically similar to nicotine, appeared to affect “far more
species than we previously thought”, said study co-author Dr Nick
Isaac of the UK’s Centre for Ecology and Hydrology, a research
organisation.
“Neonicotinoids
are harmful. We can be very confident about that.”
The findings will
fuel the debate over the mysterious disappearance of bees in several
countries. In the US a collapse of honeybee colonies — dubbed the
“bee-pocalypse” — has raised fears of a pollination crisis.
Bees and other
insects are estimated to pollinate nearly 10 per cent of the world’s
food crops.
Scientists have
pinpointed possible causes for the decline, including parasites,
habitat loss and climate change. But some studies have suggested a
link with neonicotinoids, which are made by big agrichemical
companies such as Germany’s Bayer and Syngenta of Switzerland.
The EU imposed a
two-year moratorium on three types of neonicotinoid in 2013, a move
that Syngenta said was based on “poor science”.
Bayer has said
studies in the US, Canada, Germany and elsewhere have linked poor bee
health with mites and viruses, not insecticides, and that big falls
in bee populations date back to the early 1900s.
The British research
tries to fill gaps from earlier studies, which looked at as few as
three species of commercially bred bees exposed to neonicotinoids in
laboratories over a relatively brief period of time. This time
scientists studied 62 species of wild bees over nearly 18 years from
1994, using data collected by volunteers in Britain’s Bees, Wasps
and Ants Recording Society and other sources.
Nearly half the
species studied forage on oilseed rape, a flowering plant that turns
fields into a sea of bright yellow and produces an increasingly
sought-after vegetable oil that is used to make salad dressing and
biodiesel.
Oilseed rape,
production of which has risen globally in the past 20 years, is one
of the main crops treated with neonicotinoids worldwide, including in
the UK after 2002.
The study, published
in the Nature Communications journal on Tuesday, suggested that
neonicotinoids had caused bee species that fed on oilseed rape to
become 10 per cent less widespread on average, with the worst
affected species declining 30 per cent.
Dr Ben Woodcock, the
paper’s lead author, said the findings were important because they
covered such a large number of species over a long period and were
applicable globally.
“People had an
idea that something might be happening, but nobody had an idea of
what the scale of that impact potentially was,” he told reporters
in London.
“We are seeing
correlative long-term evidence that there is an impact of
neonicotinoids, particularly for species that feed on oilseed rape —
a negative impact.”
How the outcome of a
debate on chemical use in the US and Europe could impact on the
insects
The EU moratorium
was imposed after scientists at the European Food Safety Authority
examined the risks posed to bees. Their assessment is due to be
updated by January, and the study’s authors said they hoped their
research would be taken into account.
However, they
declined to say if they thought the moratorium should be extended or
made permanent.
“Our job is to
provide the independent evidence to the policymakers,” said Richard
Pywell of the Centre for Ecology and Hydrology. “It’s not our job
to decide upon policy.”
The study says it
may be possible to grow oilseed rape without extensive use of
neonicotinoids. It points to recent UK analysis showing that the use
of the pesticides does not boost farmer profits on average.
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