Hommels

Und wenn es plötzlich keine Insekten mehr gäbe? Die Entomologen stellen sich die Frage immer wieder, und wenn auch die Prognosen variieren, so herrscht in einem Punkt Einigkeit: Das menschliche Leben, wie wir es kennen, würde wahrscheinlich enden. Der namhafte Entomologe Edward O. Wilson, ausgezeichnet mit zwei Pulitzerpreisen und der National Medal of Science, gibt den Menschen nach dem hypothetischen Aussterben aller Wirbellosen (von denen Insekten die Mehrzahl stellen) noch zehn Jahre. Der Science-fiction-Autor Charles Pellegrino dagegen, der in seinem Roman «Dust» die katastrophalen Folgen eines globalen, programmierten Aussterbens aller Insekten beschreibt, lässt es weniger als sechs Monate dauern, bis die Menschheit auf eine Hand voll bedauernswerte, in alle Welt zerstreute Überlebende geschrumpft ist.

In “Silent Spring”, Rachel Carson gave society a warning about the dangers of organochlorine insecticides such as DDT or dieldrin: “These sprays, dusts, and aerosols are now applied almost universally to farms, gardens, forests, and homes - non-selective chemicals that have the power to kill every insect, the "good" and the "bad", to still the song of birds and the leaping of fish in the streams, to coat the leaves with a deadly film, and to linger on in soil - all this, though the intended target may be only a few weeds or insects. Can anyone believe it is possible to lay down such a barrage of poisons on the surface of the earth without making it unfit for all life?.” The situation is not much different today. Wild pollinators and honeybees alike have been facing an increasingly toxic landscape since the introduction and rapid uptake of neonicotinoids in the late 1990s. Mining data from USDA, EPA, industry and California's pesticide use reporting system (the only one of it's kind), here's a snapshot of what bees are facing in the field:
- Over 2 million pounds of clothianidin, imidacloprid and thiamexotham (three neonicotinoids) are used in an average year.
- At least 143 million of our 442 million acres of cropland is planted with crops treated with one of three neonicotinoids: clothianidin, imidacloprid and/or thiamexotham.
- 83+ million of these acres are corn, upon which honeybees rely for core nutrition (corn is wind pollinated, it doesn't need bees for pollination, but its sheer abundance of pollen makes it a staple source of bee forage).

Most of us would not like to think we might be implicated in the decline of honeybees worldwide, or in the decreasing numbers of bumblebees, butterflies and farmland birds nearer home, but two scientific papers published at the end of last month suggest we are. The scientists’ findings about the effect of the latest generation of pesticides on bees and other pollinators mean we should all re-examine what we buy. For someone who, as concern has grown, has tried to keep a sense of proportion about the possible effects of a group of pesticides called neonicotinoids — nicotine-like substances that were introduced in the 1990s
— the sense of betrayal runs deep. I expect multinational pesticide companies to play down evidence they don’t like and to play up the importance of pesticides when it comes to feeding the world. I don’t expect the people we pay to protect our environment to operate complacently on the same assumptions. What we are talking about is nothing less than the poisoning of the countryside on a scale greater than Rachel Carson wrote about in Silent Spring, her classic exposure of the first generation of synthetic pesticides. Three million acres of Britain are treated with the new pesticides. Their true effects were missed by regulators despite the erection, under the European Union, of the greatest edifice of environmental legislation yet. No wonder an English scientist quoted in the normally cautious journal Science predicts that these two scientific papers will cause “an absolute firestorm”. The Xerces Society for Invertebrate Conservation recently published a review of research into the effects of neonicotinoid insecticides on bees, with recommendations for action (attached). Attached also is an article on the influence of Bayer Cropscience on Dutch policy makers (which appeared the magazine "Vrij Nederland" on April 4, 2012).

The coming together of a major problem and a leading problem-solver can be a significant moment, and we witnessed one such last week with the news that Professor Bob Watson is going to have a close personal look at the issue of neonicotinoids, the new nerve-agent pesticides, and their effect on bees and other pollinating insects. For Bob Watson is a towering figure, and that is the bigger significance: he is the world's leading expert on policy responses to global change, on what we should do about climate change, the loss of wildlife, the destruction of ecosystems and the need to feed a world of nine billion people – and in particular, on how we should respond as a society when all these difficulties come together, as they are now. On Monday, the Defra website carried its own story headlined: "Myth Busters", saying the Independent story was not true. It said: "The truth: Bob Watson did not order a review of the evidence......he asked to receive regular updates on new research into the possible effects on insects which are not the target species of pesticides." This is what Bob Watson told me on Friday: "The real Defra position is the following. We will absolutely look at the University of Stirling work, the French work, and the American work that came out a couple of months ago. We must look at this in real detail to see whether or not the current British position is correct or is incorrect." If that's not a review of the evidence, what is? The Xerces Society for Invertebrate Conservation recently published a review of research into the effects of neonicotinoid insecticides on bees, with recommendations for action (attached).

Species belonging to the family of the Apidae such as the bumblebee Bombus terrestris are widely used for the pollination of greenhouse crops. However, to obtain satisfactory yields growers need to protect their crops against plant diseases and pests who are up until today still mainly controlled by chemical pesticides. Consequently exposure to pesticides during foraging is not unlikely. To assess detrimental effects (lethal and sublethal effects) on the vector following pesticide exposure the classic toxicity test using microcolonies can be applied. However, beside toxicity pesticides are known to induce sublethal effects on the foraging behaviour. In this context, a foraging behaviour test was developed allowed to assess the impact on the foraging activity by use of two endpoints drone production and nest development.