Outlawing a type of insecticides is not a panacea. AP Photo/Ben Margot
Scientists discover what’s killing the bees and it’s worse than you thought
As we’ve written before, the mysterious mass die-off of honey bees that pollinate $30 billion worth of crops in the US has so decimated America’s apis mellifera population that one bad winter could leave fields fallow. Now, a new study has pinpointed some of the probable causes of bee deaths and the rather scary results show that averting beemageddon will be much more difficult than previously thought.
Scientists had struggled to find the trigger for so-called Colony Collapse Disorder (CCD) that has wiped out an estimated 10 million beehives, worth $2 billion, over the past six years. Suspects have included pesticides, disease-bearing parasites and poor nutrition. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists at the University of Maryland and the US Department of Agriculture have identified a witch’s brew of pesticides and fungicides contaminating pollen that bees collect to feed their hives. The findings break new ground on why large numbers of bees are dying though they do not identify the specific cause of CCD, where an entire beehive dies at once.
When researchers collected pollen from hives on the east coast pollinating cranberry, watermelon and other crops and fed it to healthy bees, those bees showed a significant decline in their ability to resist infection by a parasite called Nosema ceranae. The parasite has been implicated in Colony Collapse Disorder though scientists took pains to point out that their findings do not directly link the pesticides to CCD. The pollen was contaminated on average with nine different pesticides and fungicides though scientists discovered 21 agricultural chemicals in one sample. Scientists identified eight ag chemicals associated with increased risk of infection by the parasite.
Most disturbing, bees that ate pollen contaminated with fungicides were three times as likely to be infected by the parasite. Widely used, fungicides had been thought to be harmless for bees as they’re designed to kill fungus, not insects, on crops like apples.
“There’s growing evidence that fungicides may be affecting the bees on their own and I think what it highlights is a need to reassess how we label these agricultural chemicals,” Dennis vanEngelsdorp, the study’s lead author, told Quartz.
Labels on pesticides warn farmers not to spray when pollinating bees are in the vicinity but such precautions have not applied to fungicides.
Bee populations are so low in the US that it now takes 60% of the country’s surviving colonies just to pollinate one California crop, almonds. And that’s not just a west coast problem—California supplies 80% of the world’s almonds, a market worth $4 billion.
In recent years, a class of chemicals called neonicotinoids has been linked to bee deaths and in April regulators banned the use of the pesticide for two years in Europe where bee populations have also plummeted. But vanEngelsdorp, an assistant research scientist at the University of Maryland, says the new study shows that the interaction of multiple pesticides is affecting bee health.
“The pesticide issue in itself is much more complex than we have led to be believe,” he says. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”
The study found another complication in efforts to save the bees: US honey bees, which are descendants of European bees, do not bring home pollen from native North American crops but collect bee chow from nearby weeds and wildflowers. That pollen, however, was also contaminated with pesticides even though those plants were not the target of spraying.
“It’s not clear whether the pesticides are drifting over to those plants but we need take a new look at agricultural spraying practices,” says vanEngelsdorp.
in http://qz.com/107970/scientists-discover-whats-killing-the-bees-and-its-worse-than-you-thought/#
Tradução: (do google :( )
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Scientists had struggled to find the trigger for so-called Colony Collapse Disorder (CCD) that has wiped out an estimated 10 million beehives, worth $2 billion, over the past six years. Suspects have included pesticides, disease-bearing parasites and poor nutrition. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists at the University of Maryland and the US Department of Agriculture have identified a witch’s brew of pesticides and fungicides contaminating pollen that bees collect to feed their hives. The findings break new ground on why large numbers of bees are dying though they do not identify the specific cause of CCD, where an entire beehive dies at once.
When researchers collected pollen from hives on the east coast pollinating cranberry, watermelon and other crops and fed it to healthy bees, those bees showed a significant decline in their ability to resist infection by a parasite called Nosema ceranae. The parasite has been implicated in Colony Collapse Disorder though scientists took pains to point out that their findings do not directly link the pesticides to CCD. The pollen was contaminated on average with nine different pesticides and fungicides though scientists discovered 21 agricultural chemicals in one sample. Scientists identified eight ag chemicals associated with increased risk of infection by the parasite.
Most disturbing, bees that ate pollen contaminated with fungicides were three times as likely to be infected by the parasite. Widely used, fungicides had been thought to be harmless for bees as they’re designed to kill fungus, not insects, on crops like apples.
“There’s growing evidence that fungicides may be affecting the bees on their own and I think what it highlights is a need to reassess how we label these agricultural chemicals,” Dennis vanEngelsdorp, the study’s lead author, told Quartz.
Labels on pesticides warn farmers not to spray when pollinating bees are in the vicinity but such precautions have not applied to fungicides.
Bee populations are so low in the US that it now takes 60% of the country’s surviving colonies just to pollinate one California crop, almonds. And that’s not just a west coast problem—California supplies 80% of the world’s almonds, a market worth $4 billion.
In recent years, a class of chemicals called neonicotinoids has been linked to bee deaths and in April regulators banned the use of the pesticide for two years in Europe where bee populations have also plummeted. But vanEngelsdorp, an assistant research scientist at the University of Maryland, says the new study shows that the interaction of multiple pesticides is affecting bee health.
“The pesticide issue in itself is much more complex than we have led to be believe,” he says. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”
The study found another complication in efforts to save the bees: US honey bees, which are descendants of European bees, do not bring home pollen from native North American crops but collect bee chow from nearby weeds and wildflowers. That pollen, however, was also contaminated with pesticides even though those plants were not the target of spraying.
“It’s not clear whether the pesticides are drifting over to those plants but we need take a new look at agricultural spraying practices,” says vanEngelsdorp.
in http://qz.com/107970/scientists-discover-whats-killing-the-bees-and-its-worse-than-you-thought/#
Tradução: (do google :( )
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Proibir um tipo de inseticidas não é uma panacéia. AP Photo / Ben MargotCientistas descobrem o que está matando as abelhas e é pior do que se pensavaPor Todd Woody - 24 de julho de 2013Como já escrevi antes, a massa misteriosa mortandade de abelhas que polinizam US $ 30 bilhões de culturas em que os EUA tão dizimada apis mellifera população da América que um inverno ruim poderia deixar os campos em pousio. Agora, um novo estudo identificou algumas das causas prováveis da morte de abelhas e os resultados bastante assustadores mostram que evitar beemageddon será muito mais difícil do que se pensava anteriormente.Os cientistas tinham dificuldade em encontrar o gatilho para o chamado Colony Collapse Disorder (CCD), que dizimou cerca de 10 milhões de colméias, no valor de US $ 2 bilhões nos últimos seis anos. Os suspeitos têm incluído pesticidas, parasitas transmissores de doenças e má nutrição. Mas, em um primeiro de seu tipo de estudo publicado hoje na revista PLoS ONE, os cientistas da Universidade de Maryland e do Departamento de Agricultura dos EUA identificaram bebida de pesticidas e fungicidas contaminam pólen que as abelhas recolhem para alimentar suas colméias de uma bruxa. Os resultados inovar sobre o porquê de um grande número de abelhas estão morrendo embora não identificar a causa específica da CCD, onde uma colméia inteira morre imediatamente.Quando os pesquisadores coletaram o pólen das colméias, na costa leste cranberry polinização, melancia e outras culturas e alimentou a abelhas saudáveis, essas abelhas mostraram um declínio significativo na sua capacidade de resistir à infecção por um parasita chamado Nosema ceranae. O parasita tem sido implicado no Colony Collapse Disorder embora os cientistas teve o cuidado de salientar que as suas conclusões não vincular diretamente os pesticidas a CCD. O pólen foi contaminado, em média, com nove pesticidas e fungicidas diferentes embora os cientistas descobriram 21 agrotóxicos em uma amostra. Cientistas identificaram oito ag produtos químicos associados com maior risco de infecção pelo parasita.O mais preocupante, as abelhas que comem pólen contaminados com fungicidas foram três vezes mais chances de serem infectados pelo parasita. Amplamente utilizado, fungicidas tinha sido pensado para ser inofensivo para as abelhas como eles são concebidos para matar fungos, não insetos, em culturas como maçãs."Há evidências crescentes de que fungicidas podem estar afetando as abelhas por conta própria e eu acho que o que ele destaca é a necessidade de reavaliar a forma como rotular esses produtos químicos agrícolas", Dennis vanEngelsdorp, principal autor do estudo, disse Quartz.Rótulos dos pesticidas alertar os agricultores para não pulverizar quando as abelhas são polinizadoras na vizinhança, mas essas precauções não ter aplicado aos fungicidas.Populações de abelhas são tão baixos em que os EUA agora tem 60% das colônias de sobreviventes do país apenas para polinizar uma cultura Califórnia, amêndoas. E isso não é apenas um problema costa oeste da Califórnia fornece 80% das amêndoas do mundo, um mercado de US $ 4 bilhões.Nos últimos anos, uma classe de substâncias químicas chamadas neonicotinóides tem sido associada à morte de abelhas e reguladores de abril proibiu o uso do pesticida por dois anos na Europa, onde as populações de abelhas também despencou. Mas vanEngelsdorp, um cientista assistente de pesquisa na Universidade de Maryland, diz que o novo estudo mostra que a interação de vários pesticidas está afetando a saúde das abelhas."A questão de pesticidas em si é muito mais complexa do que temos levado a acreditar ser", diz ele. "É muito mais complicado do que apenas um produto, o que significa, naturalmente, a solução não está em apenas proibir uma classe de produto."O estudo descobriu outra complicação nos esforços para salvar as abelhas: as abelhas norte-americanas, que são descendentes de abelhas européias, não trazer para casa o pólen das culturas nativas norte-americanas, mas coletar abelha comida de ervas daninhas e flores silvestres próximas. Isso pólen, no entanto, também estava contaminado com pesticidas, mesmo que essas plantas não foram o alvo de pulverização."Não está claro se os pesticidas estão à deriva sobre a essas plantas, mas precisamos ter um novo olhar sobre as práticas de pulverização agrícola", diz vanEngelsdorp.
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