Sweet Bait Lures Malaria Mosquitoes

    Israeli(以色列) researchers say they have developed a powerful bait that effectively attracts and kills malaria¹-infected mosquitoes but is completely harmless to humans and other animals.
    The toxic² sugar bait developed by scientists at Hebrew University Medical Center in Jerusalem is made with a combination（结合,组合） of fruit juice essences, which are attractive to mosquitoes, and boric acid - a mild, inorganic³ powder that kills insects when they ingest it.
    In experiments in a semi-arid region of Mali, in West Africa, the bait - in this case a blend of boric acid with guava and honey-melon fragrances⁴ - was applied⁵ using a hand sprayer on the vegetation near a cluster of man-made ponds. These ponds are important dry-season water supplies for local villagers and their livestock⁶. They are also breeding grounds for Anopheles gambiae, the mosquito that carries the most deadly form of malaria.
    For comparison, investigators⁷ sprayed grasses and leaves near other ponds with a solution of sweet fragrances only. Both baits contained a dye that marked any mosquito making contact, so scientists could count how many had actually fed on the lure⁸.
    Josef Schlein, a medical entomologist who led the study, says the results after 38 days showed  the bait containing both sweet fragrances(芬芳,香气) and boric acid proved to be very effective at killing⁹ mosquitoes.
    "In Mali, we got down by some 80 percent, the females, and 90 percent of the males," he said. "But the area is full of little ponds in there, so it is impossible to stop mosquitoes from flying from an untreated pond to a treated pond."At the control sites that were treated with fragrances only, Schlein says upwards¹⁰ of 75 percent of mosquitoes fed on the fake bait.
    Schlein explains most people don’t realize that female mosquitoes typically feed on sweet plant nectars to survive.  Their more familiar blood meals, when mosquitoes bite people, are part of the reproductive cycle.
    The researchers’ goal now is to make a lure that’s even more irresistible¹¹ to mosquitoes.
    Research leader Josef Schlein notes that boric acid poses little risk to humans and other mammals, so it’s possible a mosquito lure could be developed for use indoors. Given the non-toxic simplicity¹² of this new bait, the Hebrew University entomologist says it’s a marvel¹³ that other scientists didn't think of it sooner.
    "Yes. It was also a real surprise to us," he said. "If they go somewhere and they are strongly attracted to something, what else do we want to do with mosquitoes except kill them?"An article describing the malaria mosquito bait is published in Malaria Journal.（本文由在线英语听力室整理编辑）

1 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

2 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

3 inorganic   

adj.无生物的；无机的

参考例句：

• The fundamentals of inorganic chemistry are very important.无机化学的基础很重要。
• This chemical plant recently bought a large quantity of inorganic salt.这家化工厂又买进了大量的无机盐。

4 fragrances   

n.芳香，香味( fragrance的名词复数 )；香水

参考例句：

• The bath oil comes in various fragrances. 这种沐浴油有不同的香味。
• This toilet soap lathers so nicely and has several fragrances. 这种香皂起泡很多，并且有好几种香味。 来自《现代汉英综合大词典》

5 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

6 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

7 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

8 lure   

n.吸引人的东西，诱惑物；vt.引诱，吸引

参考例句：

• Life in big cities is a lure for many country boys.大城市的生活吸引着许多乡下小伙子。
• He couldn't resist the lure of money.他不能抵制金钱的诱惑。

9 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

10 upwards   

adv.向上，在更高处...以上

参考例句：

• The trend of prices is still upwards.物价的趋向是仍在上涨。
• The smoke rose straight upwards.烟一直向上升。

11 irresistible   

adj.非常诱人的，无法拒绝的，无法抗拒的

参考例句：

• The wheel of history rolls forward with an irresistible force.历史车轮滚滚向前，势不可挡。
• She saw an irresistible skirt in the store window.她看见商店的橱窗里有一条叫人着迷的裙子。

12 simplicity   

n.简单，简易；朴素；直率，单纯

参考例句：

• She dressed with elegant simplicity.她穿着朴素高雅。
• The beauty of this plan is its simplicity.简明扼要是这个计划的一大特点。

13 marvel   

vi.(at)惊叹vt.感到惊异；n.令人惊异的事

参考例句：

• The robot is a marvel of modern engineering.机器人是现代工程技术的奇迹。
• The operation was a marvel of medical skill.这次手术是医术上的一个奇迹。