Bijensterfte, oorzaken en gevolgen

Forum bijdrage aan Agrarisch Dagblad 5mrt 2010

De nieuwe Nederlandse regelgeving om bijensterfte tegen te gaan, gaat niet ver genoeg, vindt hoogleraar Jeroen van der Sluijs. Er kan beter geïnvesteerd worden in een bijvriendelijke maisteelt, in plaats van een symbolische investering door het ombouwen van maiszaaimachines.

Lees het artikel op de website van Agrarich Dagblad

By MITCH LIES, Capital Press

A national conservation organization has filed a notice of intent to sue the Environmental Protection Agency for failing to adequately regulate nearly 400 pesticides for their effect on threatened and endangered species.

By Reese Halter, Ph.D. • January 7, 2010

Over the past three years, more than 50 billion honeybees have died. Scientists understand the causes, and now we need everyone to lend a helping hand.

NEW YORK, New York, January 4, 2010 (ENS) – A pesticide approved just 18 months ago must be taken off the market because it could be toxic to America's honey bees, already in steep decline.

AGD.nl 05 jan 2010 14:43

Er gaan in 2010 nieuwe eisen gelden bij het zaaien van mais, meldt het CTGB.

Aanleiding is de bijensterfte. Pneumatische (onderdruk/vacuüm) zaaimachines moeten per 1 januari 2010 zijn voorzien van zogeheten deflectoren. Deze deflectoren buigen de luchtstroom af naar de grond en reduceren zodoende de drift met meer dan 85 procent.

Tot nog toe blaast de pneumaat de lucht die vrijkomt voor het creëren van het vacuüm voor zaaien omhoog of opzij. Stof met insecticide in die lucht kan daardoor naast het maïsveld op bloeiende planten terecht komen. In 2008 leidde de combinatie van slecht gecoat maïszaad, ongunstig weer en zaaien met pneumaten in het buitenland tot hoge bijensterfte.

Paul Monaghan, Manchester, UK, The Co-operative

In their article "The truth about the disappearing honeybees" Marcelo Aizen and Lawrence Harder make withering mention of the film Vanishing of the Bees , and go on to assert that there is no pollination crisis (24 October, p 26). Yet no one has so far been able to demonstrate with any confidence what is behind the decline in honeybee numbers in Europe and North America.

One of the world’s biggest pesticide companies, Syngenta, has been accused of a “howling conflict of interest” for funding research into the disappearance of honeybees - a problem which some say it may have helped cause. Graham White, a beekeeper in the Scottish Borders and an environmental author, was scathing about Syngenta’s role. “Putting Syngenta in charge of UK research into the causes of honeybee deaths is arguably the equivalent of putting the tobacco companies in charge of research into lung cancer, or asking the manufacturers of alco-pops to research the causes of teenage binge drinking,” he said. But the criticisms were angrily rejected by Syngenta’s head of corporate affairs in the UK, Andrew Coker. To suggest that the company’s funding could influence the outcome of the research was “appalling” and “an outrageous slur”.

A new U.K. film points to neonicotinoid pesticides as the root cause of colony collapse disorder among honeybees. Over the past five years, various theories regarding Colony Collapse Disorder (CCD) have been suggested, but the documentary "Vanishing of the Bees" could present the most compelling hypothesis to date. According to Michael McCarthy for The Independent, the film's assertion of "a new generation of pesticides that weakens the bees and makes them more susceptible to other diseases" already has some people up in arms. Oasis singer Liam Gallagher: "You've got to look after the birds and the bees, man. The bees are vanishing. We've got to save them before they all buzz off. It's important. It's a really worthwhile cause. Without them we're in proper bother."

Thu, Sep 17, 2009 by Paul Tukey, safelawns.org

Pesticide Implicated in Widespread Bee Deaths

While environmental activists including the SafeLawns Foundation claimed a temporary victory Wednesday, Sept. 16 in the emerging battle concerning the widespread use of imidacloprid in Worcester, Mass., beekeepers and many other observers across North America are deeply concerned about the precedents being set in the rural community.

The September 2009 issue of The Internationalist presents in seven articles a comprehensive discussion on the vanishing bees.

Le Monde, 19 septembre 2009 samedi

Pour la première fois, un consensus émerge dans le monde scientifique et apicole sur les causes des surmortalités qui affectent les populations d'abeilles de la plupart des continents. Ce tournant est perceptible au congrès Apimondia, qui réunit à Montpellier, du mardi 15 au dimanche 20 septembre, 500 scientifiques spécialistes de l'abeille et 10 000 participants.

„Uns drohen stumme Sommer“, warnt Erich Wiedemann aus Wittislingen, seines Zeichens Hobbyimker und Kreisvorsitzender der Bienenzüchter im Landkreis Dillingen. Der Zusammenhang erschließt sich erst auf den zweiten Blick, denn der von ihm beklagte Rückgang der Blüten tragenden Pflanzen betrifft nicht nur die Bienen, sondern alle Blüten aufsuchende Insekten und damit auch die Vogelwelt unserer Heimat. Die Bienen hungern. Zwar ist die Situation bei uns in den Dörfern noch am erträglichsten und insofern sind die vielen prächtigen Hausgärten im Schwäbischen ein echter Segen, doch generell geht das Problem auch an unserer Heimat nicht vorbei.

„Mitten im Sommer sind Honigbienen dem Hungertod nahe.“ Dieser Alarmruf der Imker geht durch die Medien. Nach Ansicht der Experten leiden Bienen nicht nur unter dem schwülwarmen und regnerischen Wetter, sondern auch unter der Intensivierung der Landwirtschaft.

Das Naturprodukt Honig wird gemeinhin mit friedlicher Landidylle assoziiert. Seit dort allerdings Pflanzenschutzmittel und Insektengifte regieren, fühlen sich Bienen in urbaner Umgebung wohler. Davon profitieren jetzt Pariser Imker: Über den Dächern der französischen Millionenstadt fließt neuerdings Honig.

Die Wildbienen in Hessen zieht es derzeit aus Nahrungsmangel in die Städte. «Die Bienen fliegen aus dem Wald in die Gärten, um dort ihren Hunger zu stillen», sagte die Bienenexpertin des Naturschutzverbandes BUND, Brigitte Martin, in Darmstadt. Es gebe in Hessen flächendeckend wildlebende Imken, für diese sei es vor allem im Spätsommer schwer, ausreichend Nahrungsquellen zu finden. Schuld daran sei die zunehmende Versiegelung von Grünflächen sowie die Intensivierung der Landwirtschaft. Dadurch gebe es weniger Brachflächen.

Es gibt sie mancherorts noch, Bienenvölker, die ohne imkerliche Betreuung in hohlen Bäumen leben, unbenutzte Schornsteine oder Hohlräume hinter Fassaden beziehen. Kein Imker, der an ihre Honigvorräte geht und sich etwas davon nimmt. Aber auch kein Imker, der in Notzeiten das Bienenvolk durch Fütterung rettet. Wenn solche Bienenvölker dann im Sommer nicht genügend Nahrung finden, um ihre Wintervorräte aufzustocken, dann taucht das Phänomen des Hungerschwarms auf. Da raffen die Bienen dann die letzten Reserven zusammen, sozusagen als Reiseproviant, und gehen auf Wanderschaft, um eventuell an einem anderen Ort Nahrung und Quartier zu finden.

Es ist Anfang Juni. Als der Hobby-Imker seine Beute öffnet und nach den Bienen schaut, ist er mit dem Ergebnis recht zufrieden. Das Bienenvolk hat sich gut entwickelt, Tausende von Bienen bewegen sich zwischen den Wabengassen. Die Honigwaben sind gut gefüllt und in etwa einer Woche wird der Honig reif sein. Sprich, die Bienen werden es geschafft haben, durch ihre ständigen schnellen Flügelschläge und eventuell mehrmaliges Umtragen des Honigs von einer Wabenzelle in eine andere, dessen Feuchtegrad so weit verringert zu haben, dass er danach jahrelang haltbar bleibt.

Eine Woche später: Die Honigzellen sind nicht wie erwartet randvoll mit Honig und mit einer dünnen Wachsschicht verschlossen. Im Gegenteil, der Honig scheint weniger geworden zu sein. Spontan entscheidet der Imker, nicht zu schleudern und das weitere Geschehen abzuwarten. Wie vermutet finden die Bienen in den darauf folgenden Wochen kaum mehr blühende Pflanzen, von denen sie Nektar hätten gewinnen können. Beerensträucher, Kirsch- und Apfelbäume sind verblüht, die Wiesen abgemäht.

The office tower would not look out of place in any central Tokyo street: from its glass entrance door and sweeping marble lobby to the ear-popping lift with its steady influx of salarymen. But this particular building is not only abuzz with the activity of its grey-suited workers. Its rooftop is home to a less conventional breed of tenants: more than 300,000 honeybees. The decline of the honeybee has led to experts making increasingly vociferous calls for urban dwellers to take up beekeeping in cities where pesticide contamination is low and honeybees are able to flourish.

The UK Government conservation agency’s chief scientist, Tom Tew, is urging people living in towns and cities to take up bee- keeping to halt the perilous decline in numbers. “There’s no reason why our towns and cities should exist as wildlife deserts – wildlife can thrive when we design our urban areas with nature in mind and bee-keeping is a great example of how easy it is for anyone to bring the natural world closer to their doorstep,” he says. On the fifth storey of the World Museum Liverpool, on William Brown Street, bees buzz merrily. “It’s beautiful honey,” enthuses Paul Finnegan, manager of the museum’s bug house. “Very sweet and very pure.”

Following a meeting in Downing Street today, the Soil Association has welcomed the fact that the gardens at the Prime Minister's residence has become organic. 10 Downing Street has now joined the White House in being a source - albeit small - of organic food production.

Vital research into the decline of pollinating insects will be carried out by scientists from the University of Northampton after £57,000 of funding was awarded by a charitable trust. The Finnis Scott Foundation will provide three years worth of funding for a PhD student to study pollinator diversity in the gardens of large English country houses in the region. Recent studies have suggested some regions have seen an 80 per cent drop in bee numbers as a result of intensive farming, loss of habitat and the over-use of pesticides.

When we think about bees, the first thing that springs to mind is usually the honey bee or bumble bee. Yet these two actually represent a small fraction of bees in North America. There are a staggering 4,000 species of native bees, from tiny metallic green sweat bees, short-lived squash bees, amazing clay-sculpting mason bees, leaf-cutting bees with outsize heads and large jaws, to large, blue-black carpenter bees. Now they, too, are showing signs of decline, but the threats facing them are entirely manmade. The overuse of pesticides has had an obvious, detrimental impact, but others are more insidious. Many pollinators are generalists, meaning they can feed from a wide variety of plants. When their habitats are destroyed, for example, to make way for a commercial or housing development, they at least have a chance of finding new foraging in a flower garden. The problem for native bees is that many of them specialize in particular native plants, and once those are eliminated, they starve. Habitat destruction can also mean that nesting sites suddenly become inhospitable.

De Pers, Marcel Hulspas, 10 September 2009

De ‘mysterieuze’ bijensterfte is helemaal geen mysterie. Klimaatverandering, gewasbeschermingsmiddelen, gsm-masten... allemaal flauwekul tot het tegendeel is bewezen. Het verschijnsel doet zich voor bij een te zware besmetting met de varroamijt, een beruchte parasiet, en bij hevige besmetting met nosema – een eencellige darmparasiet. Waar het volgens Tjeerd Blacquière, bijenexpert bij de Wageningse universiteit, aan schort, is vakkundige imkers.

The term "endangered species" typically conjures up images of charismatic animals—tigers, pandas, orangutans, whales, condors. But a new study says that the vast majority of species on the verge of extinction is in fact humble insects. The finding is significant, because insects play vital roles in plant pollination, decomposition, and soil processing. They also form essential links in ecological chains as plant-eaters, predators, and parasites. The loss of keystone insect species—those on which a large number of other species depend—could be especially detrimental for ecosystems and people.

A world without honey? An unsavory prospect, to be sure -- although many of us could make do with molasses, maple syrup, cane or beet sugar or (in a pinch) corn syrup. But without bees, we'd likely starve: in order to set fruit, make seed and ripen, a majority of our food crops depend on domesticated and wild bees to pollinate them. Bee populations have teetered alarmingly close to extinction in the past 15 years or so, a trend that doesn't bode well for humankind. Mite and fungal parasites are now ubiquitous to apiaries. More worrisome, though, is CCD -- colony collapse disorder -- a so-far-untreatable syndrome that for two years has wrought apocalyptic bee die-offs in much of the world. Imidacloprid's toxicity to bees is well documented and could easily contribute to die-offs in colonies where the insects' health is otherwise compromised, said Vermont Fish and Wildlife Department ecologist Leif Erikson. "We just don't know," he said in an interview last week. "But we're broadcasting this stuff around the environment as if we do know."