Hommels

De veiligheid van het wereldwijd meest gebruikte insecticide imidacloprid wordt sterk betwijfeld door een Brits parlementair onderzoek, en parlementsleden beschuldigen de toelatingsautoriteiten er van de ogen te hebben gesloten voor het risico van deze werkzame stof voor bijen. Het wetenschappelijk bewijs stapelt zich voor een verband tussen het wijdverbreide gebruik van neonicotinoïde bestrijdingsmiddelen op gewassen en de ernstige achteruitgang van de bijen en andere bestuivers, die van vitaal belang zijn bij de productie van een derde van ons voedsel. Het onderzoek heeft bewijs opgeleverd (zie bijlage), dat blijkbaar werd genegeerd door toelatingsautoriteiten, dat het giftige insecticide zich kan ophopen in de bodem tot een niveau dat vrijwel zeker dodelijk is voor de meeste insecten, met inbegrip van bijen die overwinteren in de bodem.

„Das Buch könnte ein Krimi sein“ titulierte kürzlich die Neue Rheinische Zeitung. Und das, obwohl das Buch „Das Ende der Artenvielfalt“ des holländischen Toxikologen Henk Tennekes ein Sachbuch ist. Darin belegt der Wissenschaftler den Zusammenhang zwischen dem großräumigen Einsatz von Pestiziden und dem Rückgang zahlreicher europäischer Vogel- und Insektenarten. Verantwortlich dafür sind seiner Meinung nach Neonikotinoide. Tennekes sprach auf Einladung des Instituts für Umweltwissenschaften Landau am 29. November an der Universität in Landau (Fortstraße 7, Hauptgebäude, Konferenzraum), siehe die Beilage.

It's not just domesticated bees that are in trouble. Many wild pollinators -- from the rusty patch bumblebee to the Karner blue butterfly -- are also declining in number, and some are in far worse shape. In a recent study of Midwest cornfields, University of Minnesota entomologist Karen Oberhauser linked the widespread use of Roundup and the disappearance of milkweed to an 81 percent drop in eggs of the monarch butterfly, the gaudy insect in mysterious decline across the country. The threats to these species are numerous and complicated, but biologists say the encroachment of chemical-intensive agriculture on the native prairie is certainly one of them.

Häufig werden Neonikotinoide bei der Maisbeize eingesetzt. Aufgrund ihrer Wasserlöslichkeit werden sie von der Pflanze aufgenommen und gelangen in alle Pflanzenteile einschließlich des Pollens und des Nektars. Besuchen Honigbienen Blüten von Pflanzen, die dieses Nervengift aufgenommen haben, dann nehmen sie es mit der Nahrung auf. Beim Ausbringen von gebeiztem Saatgut bleibt solches immer wieder oberflächlich liegen bzw. wird Beizstaub über die Luft weiter verfrachtet. Dieser kann sich an Blüten von benachbarten Wiesen absetzen. Dadurch kommt es auch im weiteren Umkreis der Felder zu Vergiftungen der Honigbienen mit Neonikotinoiden. Diese Nervengifte bringen nicht nur Honigbienen zum Absterben, sondern auch Wildbienen, Schmetterlinge und viele andere Kleintiere. Der Artenschwund in der Agrarlandschaft wird durch die Verwendung der Neonikotinoide weiter zunehmen. Auch Vögel sind davon betroffen. Zwar nicht durch direkte Vergiftungen, aber durch den Verlust der Nahrung.

The Environmental Audit Committee held its first and second public evidence hearings of its inquiry, Insects and Insecticides. In the morning evidence session, the Committee identified the key issues in relation to insects and insecticides with campaigners and farmers’ representatives. Topics for discussion included the current regulatory regime for pesticides, the decline of insect pollinators in the UK, organic alternatives to pesticides and the practical consequences of a hypothetical ban on the use of neonicotinoid insecticides. In the afternoon session, the Committee explored the latest scientific research on insects and insecticides with a panel of scientists who are currently active in the field. This session focused on the latest research on the effect of neonicotinoid insecticides on bees.
Transcripts :
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/c66…
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/c66…
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/c66…

Written evidence:
http://t.co/R6QiY40E

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Researchers with the Canadian Pollination Initiative (NSERC-CANPOLIN) mined numerous insect collections in Canada and the United States looking for information on the distribution and abundance of 21 eastern species of bumble bees. "It is really difficult to know if a species is in trouble unless you have good historical data for comparison. This is the first time data gathered from historical collections has been used to assess the current status of Nearctic bees across their entire native range," says Sheila Colla, a recent PhD graduate from York University who led the study. The study was based on 44,797 bee specimens collected between 1864 and 2009. Researchers used both taxonomic and geographic data found in collection records to measure the persistence and relative abundance of each species across the full range of their distribution. Of the 11 species found to be in decline, four are deemed "vulnerable", six are considered "endangered" and one is "critically endangered".

Earlier this year, two studies published in Science showed that colonies are severely affected when bees are exposed to neonicotinoid pesticides of the kind commonly sprayed on crops. In one study, exposure led to a significant loss of queens in colonies of bumblebees (Bombus terrestris). In the other, on honeybees (Apis mellifera), the insecticide interfered with the foragers’ ability to navigate back to the hive. Now, in a study published in Nature, researchers at Royal Holloway, University of London, in Egham, UK, show that low-level exposure to a combination of two pesticides is more harmful to bumblebee colonies than either pesticide on its own. The results suggest that current methods for regulating pesticides are inadequate because they consider only lethal doses of single pesticides. Low doses of pesticides have subtle effects on individual bees and can seriously harm colonies.

SCOTLAND’S multi-million pound fruit growing industry is at risk unless ministers ban key pesticides that are threatening to wipe out bees, wildlife experts warned yesterday. The Scottish Wildlife Trust is urging the Scottish Government to prevent the use of neonicotinoids after research suggested that the widely-used pesticides might have a catastrophic effect on the insects, which play a vital role in pollinating crops. Feeding on contaminated pollen and nectar affects bees’ navigational abilities, which jeopardises their chances of making it back to their colonies, it is claimed.

There is a growing body of evidence that shows that neonicotinoids have a detrimental effect at sub-lethal doses on insect pollinators. For this reason, The Wildlife Trusts believe that until it can be categorically proven that neonicotinoids are not adversely impacting pollinator populations, and by extension ecosystem health, Government should adopt the precautionary principle and place a moratorium on their use on all outdoor crops.