科学美国人60秒 SSS Pesticides Act as Honeybee Contraceptives
时间：2019-01-20 作者：英语课 分类：2016年Scientific American(八)月
Over the last year, beekeepers in the U.S. lost nearly half their honeybee hives. And there are a lot of suspected culprits for this so-called beepocalypse—from parasitic 1 mites 2, to viruses, to simple land use changes. But a study out earlier this year pointed 3 to another possibility: poor sperm 4 quality among the drone bees, leading to colony crashes. And now another group of researchers may have found a reason for the subpar sperm: neonicotinoid pesticides 5. These substances contain chemicals similar to nicotine 6 and affect insect nervous systems.
"So for the drones that were exposed to pesticides during development, it appears there were more dead sperm in their reproductive tracts 7." Geoff Williams, an entomologist at the University of Bern in Switzerland and Agroscope, a Swiss federal research facility.
Williams and his colleagues studied the effects of two neonicotinoid pesticides on honeybee drones, genetically 8 assigned to mate with queens. "They've got really big eyes so they can identify these queens flying through the air. They eat and have sex. Or try to have sex at least."
But in 20 honeybee hives Williams and his collaborators found that those drones exposed to standard environmental levels of the pesticides were shorter-lived, thus having fewer opportunities to mate. And even if the drones did survive, they had nearly 40 percent fewer living sperm than did control bees—meaning the pesticides were acting 9 like honeybee contraceptives. The study appears in the Proceedings 10 of the Royal Society B. [Lars Straub et al., Neonicotinoid insecticides serve as inadvertent insect contraceptives]
Williams says pesticides are just one of many factors assaulting bees. But it looks like the way farmers treat some crops could adversely 11 affect the pollinators those crops also rely on.
—Christopher Intagliata
- Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
- By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。
- The only discovered animals are water bears, mites, microscopic rotifers. 能够发现的动物只有海蜘蛛、螨和微小的轮虫。 来自辞典例句
- Mites are frequently found on eggs. 螨会经常出现在蛋上。 来自辞典例句
- He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
- She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。
- Only one sperm fertilises an egg.只有一个精子使卵子受精。
- In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中，一个精子使一个卵子受精。
- 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》
- Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。
- Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。
- vast tracts of forest 大片大片的森林
- There are tracts of desert in Australia. 澳大利亚有大片沙漠。
- All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
- Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物
- Ignore her,she's just acting.别理她，她只是假装的。
- During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。
- He was released on bail pending committal proceedings. 他交保获释正在候审。
- to initiate legal proceedings against sb 对某人提起诉讼