VOA标准英语2012--Studies Link Bee Decline to Insecticide

Studies Link Bee Decline to Insecticide

 Billion-dollar bees

Bees pollinate the flowers that become fruits, nuts and vegetables. The work these insects do is worth about $18 billion a year to U.S. farmers.

But honeybee colonies in the United States have been shrinking by about a third each year for the past several years. 

Colorado beekeeper Tom Theobald says the worst of the die-offs usually happen in the winter. 

“If you were a rancher, you’d go out there and you’d have a dead cow. In the case of the bees, there may or may not be a carcass,” he says. “They may have mostly disappeared with just a small remnant [of the hive] left.”

Mysterious disappearance¹

This mysterious disappearance has been termed colony collapse² disorder³. Colony collapses⁴ account for about a third of the overall loss of honeybees each year, according to the U.S. Department of Agriculture.

No one knows exactly why it happens. A parasite⁵ called the varroa mite⁶ started attacking honeybee hives in the 1980s.

But Theobald says even as beekeepers started getting the mite problem under control, “The losses not only continued but they escalated⁷. And as we look back, it appears that the reason for that is that the influence of the systemic pesticides⁸ was beginning to become more and more dominant⁹.”

Systemic pesticides called neonicotinoids first introduced in the 1990s are now commonly used to coat the seeds of many major crops. The seedlings¹⁰ absorb the chemical as they grow. So, rather than needing to indiscriminately spray a whole field, there is a little bit of insecticide inside each plant.

But that includes the plant's pollen¹¹ and nectar that the bees are after. It is not enough to kill them. Some studies have show it may be harming them nonetheless. But not all researchers have been convinced. 

Intoxicated¹² bees

In one of the new studies, researchers glued tiny microchips to the backs of honeybees. The chips tracked the insects as they came and went from their hive. 

The researchers fed the bees sugar water spiked¹³ with a low dose of a neonicotinoid and sent them out to forage¹⁴. 

They found these bees were about twice as likely to fail to return as bees not exposed to the insecticide. 

Lead author Micka?l Henry from the French national agriculture research institute, INRA, says the bees basically get drunk.

“Intoxicated honeybees with those small doses may just get lost and are unable to find their way back home,” he says.

Wild bees also affected¹⁵

And it’s not just honeybees that are affected. 

Some research has shown bumblebees have a harder time gathering¹⁶ nectar in the laboratory when exposed to neonicotinoids. Bumblebee researcher Dave Goulson at Britain’s University of Sterling¹⁷ and colleagues studied colonies in real-world conditions. 

The second study in Science, they found colonies of bees treated with a low dose of a neonicotinoid were smaller than untreated colonies. 

Most significantly, Goulson says, “There were 85 percent fewer queens produced when they’d been exposed to realistic field levels of neonicotinoids, which clearly could have very significant implications for bumblebee populations in the wild.”

Only bumblebee queens survive the winter to start new colonies each spring.

That could help explain why bumblebee populations are declining along with the honeybees. And around the world, wild pollinators like bumblebees are more important than honeybees for certain crops. 

Overdose

Bayer CropScience, which makes neonicotinoid pesticides, disputes the findings. 

“Instead of dosing the animals at field-relevant concentrations as the authors intended," says Bayer spokesman Jack¹⁸ Boyne, "they instead dosed them at levels that are far greater than what would commonly be experienced in the field." Sixty times greater, Boyne says. At that level, he says, it is not surprising that the bees were disoriented. 

And he notes that researchers are studying many other factors affecting bee populations, including parasites¹⁹, diseases, and the stress of transporting commercial beehives. 

Purdue University insect scientist Christian²⁰ Krupke agrees there are a lot of factors threatening bees. But he says the new studies give regulators something to think about.

“Our regulatory system is based on a lethal²¹ dose. Is the bee dead, or is it alive? And these studies show that these bees may be alive, but there’s a sublethal dose that’s causing harm to the colony.”

Some European regulators have banned neonicotinoids, and calls for bans in the United States are growing as well. 

1 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

2 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

3 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

4 collapses   

折叠( collapse的第三人称单数 )； 倒塌； 崩溃； （尤指工作劳累后）坐下

参考例句：

• This bridge table collapses. 这张桥牌桌子能折叠。
• Once Russia collapses, the last chance to stop Hitler will be gone. 一旦俄国垮台，抑止希特勒的最后机会就没有了。

5 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

6 mite   

n.极小的东西；小铜币

参考例句：

• The poor mite was so ill.可怜的孩子病得这么重。
• He is a mite taller than I.他比我高一点点。

7 escalated   

v.（使）逐步升级( escalate的过去式和过去分词 )；（使）逐步扩大；（使）更高；（使）更大

参考例句：

• The fighting escalated into a full-scale war. 这场交战逐步扩大为全面战争。
• The demonstration escalated into a pitched battle with the police. 示威逐步升级，演变成了一场同警察的混战。

8 pesticides   

n.杀虫剂( pesticide的名词复数 )；除害药物

参考例句：

• vegetables grown without the use of pesticides 未用杀虫剂种植的蔬菜
• There is a lot of concern over the amount of herbicides and pesticides used in farming. 人们对农业上灭草剂和杀虫剂的用量非常担忧。 来自《简明英汉词典》

9 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

10 seedlings   

n.刚出芽的幼苗( seedling的名词复数 )

参考例句：

• Ninety-five per cent of the new seedlings have survived. 新栽的树苗95%都已成活。 来自《现代汉英综合大词典》
• In such wet weather we must prevent the seedlings from rotting. 这样的阴雨天要防止烂秧。 来自《现代汉英综合大词典》

11 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

12 intoxicated   

喝醉的，极其兴奋的

参考例句：

• She was intoxicated with success. 她为成功所陶醉。
• They became deeply intoxicated and totally disoriented. 他们酩酊大醉，东南西北全然不辨。

13 spiked   

adj.有穗的；成锥形的；有尖顶的

参考例句：

• The editor spiked the story. 编辑删去了这篇报道。 来自《简明英汉词典》
• They wondered whether their drinks had been spiked. 他们有些疑惑自己的饮料里是否被偷偷搀了烈性酒。 来自辞典例句

14 forage   

n.(牛马的)饲料，粮草；v.搜寻，翻寻

参考例句：

• They were forced to forage for clothing and fuel.他们不得不去寻找衣服和燃料。
• Now the nutritive value of the forage is reduced.此时牧草的营养价值也下降了。

15 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

16 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

17 sterling   

adj.英币的(纯粹的，货真价实的)；n.英国货币(英镑)

参考例句：

• Could you tell me the current rate for sterling, please?能否请您告诉我现行英国货币的兑换率？
• Sterling has recently been strong,which will help to abate inflationary pressures.英国货币最近非常坚挺，这有助于减轻通胀压力。

18 jack   

n.插座，千斤顶，男人；v.抬起，提醒，扛举；n.（Jake）杰克

参考例句：

• I am looking for the headphone jack.我正在找寻头戴式耳机插孔。
• He lifted the car with a jack to change the flat tyre.他用千斤顶把车顶起来换下瘪轮胎。

19 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

20 Christian   

adj.基督教徒的；n.基督教徒

参考例句：

• They always addressed each other by their Christian name.他们总是以教名互相称呼。
• His mother is a sincere Christian.他母亲是个虔诚的基督教徒。

21 lethal   

adj.致死的；毁灭性的

参考例句：

• A hammer can be a lethal weapon.铁锤可以是致命的武器。
• She took a lethal amount of poison and died.她服了致命剂量的毒药死了。