Insecticides

Der Ökologische Jagdverein Niedersachsen und Bremen e. V. (ÖJV) veranstaltete gemeinsam mit dem Naturschutzbund eine Vortrags- und Diskussionsveranstaltung zum Thema „Der stumme Frühling! Schon Wirklichkeit? – Der Einfluss von Pestiziden auf die Artenvielfalt in der Natur“. Dabei ging es am Freitag, dem 27. Juni, von 15 bis 17 Uhr im Museum am Schölerberg in Osnabrück um den Einsatz von Neonicotinoiden in der Landwirtschaft. Diese hochwirksamen Insektengifte sind umstritten, weil sie nach Einschätzung von Umweltschützern im Verdacht stehen, Bienensterben ausgelöst zu haben und insgesamt großen Schaden in der Natur anzurichten. Der Ökologische Jagdverein Niedersachsen und Bremen e. V., dessen Geschäftsführer der Meppener Winfried Frölich (Arenberg) ist, hatte als Referenten den Toxikologen Henk Tennekes eingeladen. Er hat das Buch „Das Ende der Artenvielfalt. Neuartige Pestizide töten Insekten und Vögel“ verfasst. Seinem Vortrag folgte eine Podiumsdiskussion mit folgenden Teilnehmern: Henk Tennekes, Gerhard Kooiker (Ornithologe), Heidrun Meissner (Landwirtschaftskammer Niedersachsen Bezirk Osnabrück), Martin Meyer-Lührmann (Landesjägerschaft Niedersachsen), Hartmut Manning (Imker) und Stephan Boschen (Ökologischer Jagdverein). Teilnehmer der chemischen Industrie wurden angefragt aber sagten ab.

Un estudio publicado en el Boletín de Insectología en Estados Unidos, confirma la sospecha de investigadores de la relación entre los pesticidas y el problema del colapso de colonias, conocido como CCD. Para encontrar al culpable de la muerte de millones de abejas en muchas regiones de los Estados Unidos y Europa, los científicos estudiaron 18 colonias en tres locaciones de Massachusetts durante el año 2012 y 2013. Los investigadores encontraron que dos pesticidas utilizados regularmente en la agricultura eran los responsables directos por el abandono y muerte de varias colmenas. Para el estudio se expuso un tercio de las colonias a bajas dosis del pesticida Imidacloprid, mientras que el otro tercio fue expuesto al pesticida Clotianidina, los dos pertenecientes a la clase Neonicotinoide que actúa sobre el sistema nervioso de los insectos y es utilizado por los agricultores. El tercio restante no recibió ningún pesticida como método de control.

Some of the honeybees were lying on their backs, trembling and twitching. Others were crawling slowly on the ground, unable to fly. Many were motionless, lying dead in piles. Many more had simply disappeared, apparently unable to find their way back to their hives. This was the gruesome scene commercial beekeeper Steve Ellis came upon on the morning of May 7, 2013.
The sight stunned Ellis, who has owned and operated Old Mill Honey Company in Barrett, Minnesota for 35 years. "Normally in the spring, we typically expect bees to build up and get stronger," he recalled. "For a beekeeper to watch his bees be devastated in the springtime — it's like watching a little child get extremely sick and debilitated. It takes a real mental toll on you."
But almost immediately, Ellis discovered the culprit: That morning, a farmer had planted corn in a field directly adjacent to his bee yard, which housed roughly 1,300 hives at the time. He was well aware that most corn seeds are treated with a pesticide called neonicotinoids. And that day, the wind was blowing from the cornfield toward Ellis' bees, the beekeeper wrote in an incident report he sent to the US Environmental Protection Agency. The bees' only sources of food were nearby willow trees, which, Ellis surmised, had become coated with pesticide-contaminated dust. "We took a close look to see how the bees were behaving when they were trying to forage them. It was shocking what we found," Ellis said in a video he took that day documenting the massacre. "Bees literally incapacitated when they come in contact with the flowers."

We have recently been surveying what chemicals the local farmers in East Sussex use each year. Chemicals applied to two fairly typical fields, one with winter oilseed rape, one with winter wheat, in a single growing season (2012/13). I should stress that these are perfectly normal farms; not especially intensive, situated on the edge of the South Downs, an area of gentle hills, hedgerows and wooded valleys. Beautiful, rural England; Constable would have liked it here. But let’s look at it from a bee’s perspective, focussing on the oilseed rape, since this is a crop they will feed on when it flowers: firstly, the crop is sown in late summer with a seed dressing containing the insecticide thiamethoxam. This is a systemic neonicotinoid, with exceedingly high toxicity to bees. We know it is taken up by the plant, and that detectable levels will be in the nectar and pollen gathered by bees in the following spring. In November, despite the supposed protection of the neonicotinoid, the crop is sprayed with another insecticide, the charmingly named Gandalf. Gandalf contains beta-cyfluthrin, a pyrethroid. Pyrethroids are highly toxic to bees and other insects, but there should be no bees about in November so that is probably OK. The following May, when it is flowering, the crop is sprayed with another pyrethroid, alpha-cypermethrin. Less than three weeks later, the crop is blitzed with three more pyrethroids, all mixed together, a real belt-and-braces approach. Why use one when three will do? The crop is still flowering at this point (it was a late year), and would be covered in foraging bumblebees and other pollinators. In between, the crop is also treated with a barrage of herbicides, fungicides, molluscicides and fertilizers – 22 different chemicals in total.