Scientists Warn That a Widely Used Pesticide Could Be Worse for Bees Than DDT

Todd Woody Takepart.com Yahoo News 24 Jun 14;

The indiscriminate use of DDT in the mid-20th century helped nearly exterminate America’s national symbol, the bald eagle, and the pesticide itself became a symbol of an industrial society at war with nature.

Now, more than 40 years after the United States Environmental Protection Agency banned DDT, thanks in large part to the publication of Rachel Carson’s Silent Spring, a class of agricultural pesticides called neonicotinoids (neonics) poses an even more serious threat to bees, other wildlife, and entire ecosystems, according to a preview of a report to be published next week by an international group of scientists.

“In the case of acute effects alone, some neonics are at least 5,000 to 10,000 times more toxic to bees than DDT,” wrote the scientists affiliated with the Task Force on Systemic Pesticides. “The evidence is also clear that neonics pose a serious risk of harm to honey bees and other pollinators.”

Studies have implicated neonics in the mass die-off of bees that pollinate a third of the global food supply. Many scientists believe the pesticide is one of several interrelated factors—including disease, parasites, and poor nutrition—responsible for the apian catastrophe that has unfolded over the past decade.

The task force analyzed more than 800 peer-reviewed studies that investigated the impact of neonics and an insecticide called fipronil on insects like bees, mammals, birds, and reptiles. Neonics and fipronil have become pervasive in the environment over the past two decades and now account for 40 percent of the global pesticide market, according to the report.

Neonics and fipronil belong to a class of so-called systemic pesticides that are absorbed into a plant’s roots, stems, leaves, flowers, pollen, and nectar. Farmers can spray plants with neonics, but seeds are now routinely treated with the chemical, meaning that as the plant grows the pesticide remains part of the flora.

And increasingly the fauna.

“The combination of persistence (over months or years) and solubility in water has led to large scale contamination of, and the potential for accumulation in, soils and sediments, ground and surface water and treated and non-treated vegetation,” the scientists wrote. “The effects of exposure to neonics range from instant and lethal to chronic. Even long term exposure at low (non-lethal) levels can be harmful.”

Neonics are nerve poisons, but the effects extend beyond the pests the pesticide is intended to kill, according to the report, damaging bees’ ability to forage and fly and increasing their susceptibility to disease. They are less harmful to birds and mammals but can have indirect consequences, such as killing off insects those animals eat.

Still, the scientists acknowledged that what they don’t know about neonics far exceeds what they do know. For instance, tests to determine neonics’ toxicity have only been done on four of 25,000 bee species, and few toxicological studies have been carried out on other pollinators, such as butterflies.

And 96 percent of those studies have been performed in the laboratory under controlled conditions. How neonics affect the behavior of bees and other wildlife remains largely unknown.

The full report will be published next week in the journal Environment Science and Pollution Research. But the scientists left no doubt about their conclusions.

“The current extensive use of this group of persistent highly toxic chemicals is affecting global biodiversity,” the report’s authors wrote, urging governments to regulate neonics more strictly and to begin a worldwide phaseout. “Their continued use can only accelerate the global decline of important invertebrates and, as a result, risk reductions in the level, diversity, security and stability of ecosystem services.”

Widespread impacts of neonicotinoids 'impossible to deny'
Matt McGrath BBC News 24 Jun 14;

Neonicotinoid pesticides are causing significant damage to a wide range of beneficial species and are a key factor in the decline of bees, say scientists.

Researchers, who have carried out a four-year review of the literature, say the evidence of damage is now "conclusive".

The scientists say the threat to nature is the same as that once posed by the notorious chemical DDT.

Manufacturers say the pesticides are not harming bees or other species.

Neonicotinoids were introduced in the early 1990s as a replacement for older, more damaging chemicals.

They are a systemic insecticide, meaning that they are absorbed into every cell in a plant, making all parts poisonous to pests.

But some scientists have been concerned about their impact, almost since the moment they were introduced.

Much of the worry has surrounded their effects on bees.

There's been a well documented, global decline in these critical pollinators.

Many researchers believe that exposure to neonicotinoids has been an important destabilising factor for the species.

'Worldwide impacts'

In 2011, environmental campaigners, the IUCN, established an international scientific taskforce on systemic pesticides to look into the impacts of these chemicals.

The members have reviewed over 800 peer reviewed papers that have been published in the past 20 years.

Their assessment of the global impact says the threat posed goes far beyond bees.

In their report, to be published next month, they argue that neonicotinoids and another chemical called fipronil are poisoning the earth, the air and the water.

The pesticides accumulate in the soil and leach into water, and pose a significant problem for earthworms, freshwater snails, butterflies and birds.

The researchers say that the classic measurements used to assess the toxicity of a pesticide are not effective for these systemic varieties and conceal their true impact.

They point to one of the studies in the review carried out in the Netherlands.

It found that higher levels of neonicotinoids in water reduced the levels of aquatic invertebrates, which are the main prey for a whole range of species including wading birds, trout and salmon.

"There is so much evidence, going far beyond bees," Prof Dave Goulson from the University of Sussex told BBC News.

"They accumulate in soils, they are commonly turning up in waterways at levels that exceed the lethal dose for things that live in streams.

"It is impossible to deny that these things are having major environmental impacts."
DDT comparison

The scientists are very worried about the prophylactic use of neonicotinoids, where seeds are coated in the chemicals and the plant grows up with the ability to destroy pests already built in.

"It is a bit like taking antibiotics to avoid getting ill," said Prof Goulson, one of a team of 29 scientists involved in the research.

"The more they are used, the stronger the selective pressure you place on pest insects to become resistant to them. Using them as prophylactics is absolute madness in that sense."

The task force argues that with neonicotinoids and fipronil making up around a third of the world market in insecticides, farmers are over-relying on them in the same way as they once became over reliant on chemicals like DDT.

"We have forgotten those lessons and we're back to where we were in the 1960s," said Prof Goulson.

"We are relying almost exclusively on these insecticides, calendar spraying 20 times or more onto a single field, it's a completely bonkers way."

While neonicotinoids don't accumulate in human or animal tissue in the way that DDT once did, the modern pesticides are more lethal, about 6,000 times as toxic compared to the older spray.

Representatives of manufacturers say that there is nothing new in the task force study.

"There is very little credible evidence that these things are causing untoward damage because we would have seen them over 20 years of use," said Dr Julian Little from Bayer, one of the manufacturers of neonicotinoids.

"If you look at the tree bumblebee, it is eating the same food as the other bees, and is being exposed to the same pesticide load and weather conditions and yet it is flourishing, whereas some other bees are not.

"If it were pesticides causing the mass destruction of our fauna, surely you would see effects on all bees?"

The European Crop Protection Association said the task force was being selective in their evidence, pointing to recent studies carried out by industry showing that the declines in bee populations have been overstated.

"We respect the scientists who have produced this research, but it appears that they are part of a movement that brings together some academics and NGOs whose only objective is to restrict or ban the use of neonicotinoid technology regardless of what the evidence may show," a spokesperson said.

Europe already has a two-year moratorium in place meaning that neonicotinoids can't be used on flowering crops such as oilseed rape.

Last week, President Obama announced the creation of a pollinator health task force to look at the impact of pesticide exposure on bees and other insects.

Prof Goulson says that he isn't in favour of a ban.

"We have been using these things for 20 years and there's not a single study that shows they increase yield," he said.

"I'm not personally in favour of an outright ban but I think we should use them much more judiciously - if they don't benefit yield we should stop using them."

Systemic pesticides pose global threat to biodiversity and ecosystem services
IUCN media release 24 Jun 14;

The conclusions of a new meta-analysis of the systemic pesticides neonicotinoids and fipronil (neonics) confirm that they are causing significant damage to a wide range of beneficial invertebrate species and are a key factor in the decline of bees.

Concern about the impact of systemic pesticides on a variety of beneficial species has been growing for the last 20 years but the science has not been considered conclusive until now.

Undertaking a full analysis of all the available literature (800 peer-reviewed reports) the Task Force on Systemic Pesticides – a group of global, independent scientists affiliated with the IUCN Commission on Ecosystem Management and the IUCN Species Survival Commission has found that there is clear evidence of harm sufficient to trigger regulatory action.

The analysis, known as the Worldwide Integrated Assessment (WIA), to be published in the peer-reviewed Journal Environment Science and Pollution Research, finds that neonics pose a serious risk to honeybees and other pollinators such as butterflies and to a wide range of other invertebrates such as earthworms and vertebrates including birds.

Neonics are a nerve poison and the effects of exposure range from instant and lethal to chronic. Even long term exposure at low (non-lethal) levels can be harmful. Chronic damage can include: impaired sense of smell or memory; reduced fecundity; altered feeding behaviour and reduced food intake including reduced foraging in bees; altered tunneling behaviour in earthworms; difficulty in flight and increased susceptibility to disease.

“The evidence is very clear. We are witnessing a threat to the productivity of our natural and farmed environment equivalent to that posed by organophosphates or DDT," said Dr Jean-Marc Bonmatin of The National Centre for Scientific Research in France, one of the lead authors of the study. " Far from protecting food production, the use of neonics is threatening the very infrastructure which enables it, imperilling the pollinators, habitat engineers and natural pest controllers at the heart of a functioning ecosystem.”

The analysis found that the most affected groups of species were terrestrial invertebrates such as earthworms which are exposed at high levels via soil and plants, medium levels via surface water and leaching from plants and low levels via air (dusts). Both individuals and populations can be adversely affected at even low levels and by acute (ongoing) exposure. This makes them highly vulnerable to the levels of neonics associated with agricultural use.

The next most affected group is insect pollinators such as bees and butterflies which are exposed to high contamination through air and plants and medium exposure levels through water. Both individuals and populations can be adversely affected by low or acute exposure making them highly vulnerable. Then comes aquatic invertebrates such as freshwater snails and water fleas which are vulnerable to low and acute exposure and can be affected at the individual, population and community levels.

While vertebrate animals are generally less susceptible, bird populations are at risk from eating crop seeds treated with systemic insecticides, and reptile numbers have declined due to depletion of their insect prey. Microbes were found to be affected after high levels of or prolonged exposure. Samples taken in water from around the world have been found to exceed ecotoxicological limits on a regular basis.

In addition to contaminating non-target species through direct exposure (e.g. insects consuming nectar from treated plants), the chemicals are also found in varying concentrations outside intentionally-treated areas. The water solubility of neonics mean that they leach and run-off easily and have been found to contaminate much wider areas leading to both chronic and acute exposure of organisms, including in riparian zones, estuarine and coastal marine systems.

They have become the most widely used group of insecticides globally, with a global market share now estimated at around 40% and sales of over US$2.63 billion in 2011. They are also commonly used in domestic treatments to prevent fleas in cats and dogs and termites in wood structures.

“The findings of the WIA are gravely worrying,” said Maarten Bijleveld van Lexmond, Chair of the Task Force. “We can now clearly see that neonics and fipronil pose a risk to ecosystem functioning and services which go far beyond concerns around one species and which really must warrant government and regulatory attention.”

Honey bees have been at the forefront of concern about neonics and fipronil to date and limited actions have been taken, for example by the EU Commission, but manufacturers of these neurotoxicants have refuted any claims of harm. In reviewing all the available literature rather than simply comparing one report with another, the WIA has found that field-realistic concentrations of neonics adversely affect individual navigation, learning, food collection, longevity, resistance to disease and fecundity of bees. For bumblebees, irrefutable colony-level effects have been found, with exposed colonies growing more slowly and producing significantly fewer queens.

The authors strongly suggest that regulatory agencies apply more precautionary principles and further tighten regulations on neonicotinoids and fipronil and start planning for a global phase-out or at least start formulating plans for a strong reduction of the global scale of use.