Insecticides

The Government must introduce a precautionary moratorium on three pesticides linked to the decline of pollinators - imidacloprid, clothianidin and TMX – that suspends their use on flowering crops attractive to pollinators, Parliament’s cross-party green watchdog has said. Environmental Audit Committee Chair, Joan Walley MP, commented: “Defra seems to be taking an extraordinarily complacent approach to protecting bees given the vital free service that pollinators provide to our economy. If farmers had to pollinate fruit and vegetables without the help of insects it would cost hundreds of millions of pounds and we would all be stung by rising food prices. Defra Ministers have refused to back EU efforts to protect pollinators and can’t even come up with a convincing plan to encourage bee-friendly farming in the UK.” Two-thirds of wild insect pollinator species - such as bumblebees, hoverflies, butterflies, carrion flies, beetles, midges and moths - have suffered population declines in the UK. Managed honeybees have also experienced unusually high mortality rates, decreased fertility, increased susceptibility to disease and the loss of hives. Similar trends have been observed in the US and other European countries.

Pesticides are important agricultural tools often used in combination to avoid resistance in target pest species, but there is growing concern that their widespread use contributes to the decline of pollinator populations. Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food, but we know relatively little about the way that combined exposure to multiple pesticides affects neural function and behaviour. The experiments reported here show that prolonged exposure to field-realistic concentrations of the neonicotinoid imidacloprid and the organophosphate acetylcholinesterase inhibitor coumaphos and their combination impairs olfactory learning and memory formation in the honeybee. Using a method for classical conditioning of proboscis extension, honeybees were trained in either a massed or spaced conditioning protocol to examine how these pesticides affected performance during learning and short- and long-term memory tasks. We found that bees exposed to imidacloprid, coumaphos, or a combination of these compounds, were less likely to express conditioned proboscis extension towards an odor associated with reward. Bees exposed to imidacloprid were less likely to form a long-term memory, whereas bees exposed to coumaphos were only less likely to respond during the short-term memory test after massed conditioning. Imidacloprid, coumaphos and a combination of the two compounds impaired the beesʼ ability to differentiate the conditioned odour from a novel odour during the memory test. Our results demonstrate that exposure to sublethal doses of combined cholinergic pesticides significantly impairs important behaviours involved in foraging, implying that pollinator population decline could be the result of a failure of neural function of bees exposed to pesticides in agricultural landscapes.

Surface runoff is an important process that affects the local water balance and causes soil erosion and rapid solute transport towards ditches, streams, and rivers. Surface runoff is the fastest route from field to stream and the main transport route for sediment and adsorbed contaminants, such as pesticides. It is the main contributor of pesticides to surface water bodies. The agricultural areas in The Netherlands most vulnerable to surface runoff are peat grasslands, where groundwater levels are kept close to the surface (less than 60 cm below soil surface), riverine heavy clay grasslands with low permeability and drainage by superficial trenches (less than 40 cm below soil surface), and sandy or clay soils with topsoil or subsoil compaction caused by treading, overstress due to large wheel loads of agricultural machinery, and tillage.

Are people good? Is humankind basically benign? In our current belief system, which we might term liberal secular humanism, which has held sway in the West since the Second World War, and which promotes human progress and well-being, only one response is permitted: Yes, of course! Any suggestion that there might be something wrong with people as a whole, with Man as a species, is absolute anathema. But today, two circumstances come together to prompt me to pose the question once more. The first is the ending, this week, of my 15 years as Environment Editor of The Independent. It has been a privilege beyond measure to work for so long for a wonderful newspaper which has put the environment at the heart of its view of the world. We are proud of all we have done about it, from raising the question, in 2000, of the mysterious disappearance of the house sparrow from London and other major cities – we offered a £5,000 prize for a proper scientific explanation, but the mystery remains – to devoting the whole of the front page, in 2011, to the then hardly recognised threat of neonicotinoid insecticides, now an obsession around the globe. But there have been what you might call side effects. For if, over the past decade and a half, you have closely observed what is happening to the Earth, week in, week out, you may take a dark view of the future; and I do. The reason is that the Earth is under threat, as it has never been before, from the ever more oppressive scale of the human enterprise: from the activities of a world population which doubled from three to six billion in four short decades, between 1960 and 2000, and which, in the four decades to come, will probably increase by three billion more. These activities are now wiping out ecosystems and species, across the world, at an ever increasing rate: the forests are chainsawed; the oceans are stripmined of their fish; the rivers, especially in the developing world, are ever more polluted; the farmland is rendered sterile of all but the monoculture crop by demented dosing with pesticides; the farmland insects and wild flowers and many of the birds have gone.

The European Commission said, on 19 March, that it would refer its proposal for a ban on the use of three neonicotinoid insecticides (clothianidin, imidacloprid and thiametoxam) on crops attractive to honeybees to the Appeal Committee after an inconclusive vote in the Standing Committee on the Food Chain and Animal Health last week (see Europolitics4608). Announcing the Commission’s decision at the Agriculture Council, Health and Consumer Policy Commissioner Tonio Borg pledged to do his utmost to “find solutions that command the widest possible support”. “The health of our bees is of paramount importance – we have a duty to take proportionate yet decisive action to protect them wherever appropriate,” he added, reiterating his determination to receive qualified majority support at the Appeal Committee for his proposal. “The Commission still envisages to have measures in place by 1 July 2013,” Borg’s services said in a separate statement. No date of the vote in the Appeal Committee was given at this stage.

Insgesamt 275 Vereinsmitglieder und Gäste (neuer Rekord seit Altenburg 2007!) fanden sich am vergangenen Wochenende (22-24. März 2013) zur 51. Jahresversammlung und Sächsischen Ornithologentagung des Vereins Sächsischer Ornithologen in der westsächsischen Kleinstadt Hohenstein-Ernstthal ein, wo das „Schützenhaus“ beste Tagungsbedingungen bot. Höhepunkt im wissenschaftlichen Vortragsprogramm am Sonnabend war mit Sicherheit der Vortrag des niederländischen Toxikologen und Krebsforschers Dr. Henk Tennekes, der über neuartige Pestizide in der Landwirtschaft und deren katastrophalen Folgen auf die Nahrungskette in der Natur sprach. Viele Zuhörer zeigten sich nach diesen Ausführungen betroffen, ja geschockt und forderten eine Reaktion vom Verein. Wie daher zur Mitgliederversammlung beschlossen, wird der VSO eine entsprechende Petition an die Bundesregierung und die EU richten.

As part of a study on impacts from the world’s most widely used class of insecticides, nicotine-like chemicals called neonicotinoids, American Bird Conservancy (ABC) has called for a ban on their use as seed treatments and for the suspension of all applications pending an independent review of the products’ effects on birds, terrestrial and aquatic invertebrates, and other wildlife. “It is clear that these chemicals have the potential to affect entire food chains. The environmental persistence of the neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative and largely irreversible mode of action in invertebrates raise significant environmental concerns,” said Cynthia Palmer, co-author of the report and Pesticides Program Manager for ABC, one of the nation’s leading bird conservation organizations. ABC commissioned world renowned environmental toxicologist Dr. Pierre Mineau to conduct the research. The 100-page report (attached), “The Impact of the Nation’s Most Widely Used Insecticides on Birds,” reviews 200 studies on neonicotinoids including industry research obtained through the US Freedom of Information Act. The report evaluates the toxicological risk to birds and aquatic systems and includes extensive comparisons with the older pesticides that the neonicotinoids have replaced. The assessment concludes that the neonicotinoids are lethal to birds and to the aquatic systems on which they depend.

In the past decade, many studies have implicated a class of pesticides known as “neonicotinoids” in the declines of pollinator populations, including bumble bees and honey bees. The toxic impact that these chemicals may be having on bees and other insects has brought them the most attention recently, and rightly so; one-third of the U.S. diet depends on pollinator services and they contribute over $15 billion to the U.S. agricultural economy. Pollinator losses represent a serious threat to the agricultural industry and our nation’s food security. First introduced in the 1990s in response to widespread pest resistance as well as public health objections to older pesticides, the neonicotinoid class of insecticides are now the most widely used insecticides in the world; it is difficult to find pest control commodities that do not contain one or several of these chemicals. The environmental persistence of neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative effects on invertebrates raise environmental concerns that go well beyond bees. A new American Bird Conservancy commissioned report by toxicologist Pierre Mineau reviews the effects on avian species and on the aquatic systems on which they depend. Larger ecosystem impacts and the relationship between neonicotinoids and alarming declines of birds, bees, and other organisms will be addressed.