第一部分 英譯漢必譯題
Mangoes in Africa, as elsewhere, often fall prey to fruit flies, which destroy about 40% of the continent„s crop. In fact, fruit flies are so common in African mangoes that America has banned their import altogether, to protect its own orchards. African farmers, meanwhile, have few practical means to defend their fruit. Chemical pesticides are expensive. And even for those who can afford them they are not that effective since, by the time a farmer spots
an infestation, it is too late to spray.
Agricultural scientists have also looked at controlling fruit flies with parasitic wasps. But the most common ones kill off only about one fly in 20, leaving plenty of survivors to go on the rampage. Lethal traps baited with fly-attracting pheromones are another option. But they, too, are expensive. Instead, most farmers simply harvest their fruit early, when it is not yet fully ripe. This makes it less vulnerable to the flies, but also less valuable.
Farmers whose trees are teeming with worker ants, however, do not need to bother with any of this. In a survey of several orchards in Benin, Dr van Mele and his colleagues found an average of less than one fruit-fly pupa in each batch of 30 mangoes from trees where worker ants were abundant, but an average of 77 pupae in batches from trees without worker ants.
The worker ants, it turns out, are very thorough about hunting down and eating fruit flies, as well as a host of other pests.
Worker ants have been used for pest control in China and other Asian countries for centuries. The practice has also been adopted in Australia. But Dr van Mele argues that it is particularly suited to Africa since worker ants are endemic to the mango-growing regions of the continent, and little training or capital is needed to put them to work. All you need do is locate a suitable nest and run string from it to the trees you wish to protect. The ants will then quickly find their way to the target. Teaching a group of farmers in Burkina Faso to use worker ants in this way took just a day, according to Dr van Mele. Those farmers no longer use pesticides to control fruit flies, and so are able to market their mangoes as organic to eager European consumers, vastly increasing their income. The ants, so to speak, are on the march.
其他參考譯文:
如同其他地區(qū)一樣,非洲芒果產(chǎn)區(qū)也飽受果蠅困擾,果蠅泛濫使芒果減產(chǎn)達(dá) 40%左 右。事實(shí)上,非洲芒果中果蠅屢見(jiàn)不鮮,美國(guó)已下令對(duì)非洲芒果實(shí)施進(jìn)口禁令,保護(hù)本 國(guó)果園免受果蠅之害。但與此同時(shí),非洲果農(nóng)面對(duì)果蠅侵襲幾乎無(wú)計(jì)可施?;瘜W(xué)殺蟲(chóng)劑十分昂貴,即便買(mǎi)得起,殺蟲(chóng)劑滅蠅效果也不理想,因?yàn)楫?dāng)果農(nóng)發(fā)現(xiàn)有果蠅后再?lài)姙⑼鶠闀r(shí)已晚。
農(nóng)業(yè)科學(xué)家也曾經(jīng)嘗試?yán)眉纳鋪?lái)防治果蠅蟲(chóng)害。但是,最常見(jiàn)的寄生蜂僅能殺 死二十分之一的果蠅,躲過(guò)一劫的果蠅則繼續(xù)為非作歹。還有一種方法是利用果蠅誘捕 器,通過(guò)性誘劑引誘果蠅達(dá)到滅蠅目的。但是,這種誘捕器也是成本不菲。所以,大部 分果農(nóng)干脆趁芒果未全熟時(shí)提早采摘,這樣果蠅危害性是小了,但是芒果也賣(mài)不出好價(jià) 錢(qián)。
但是,如果芒果樹(shù)上有大量工蟻安家的話,果農(nóng)就徹底省心了。由范﹒梅爾博士和 同事在貝寧的幾家果園開(kāi)展的一項(xiàng)調(diào)查顯示,每三十個(gè)芒果中,工蟻較多的芒果樹(shù)所產(chǎn) 芒果果蠅蛹還不到 1 個(gè),而沒(méi)有工蟻的芒果樹(shù)所產(chǎn)芒果果蠅蛹達(dá)到 77 個(gè)。調(diào)查發(fā)現(xiàn),工 蟻覓食果蠅及其他害蟲(chóng),滅蠅效果很好。
利用工蟻防治病蟲(chóng)害的做法在中國(guó)及其他亞洲國(guó)家已有數(shù)百年歷史,澳大利亞也已 予以采用。但是,范﹒梅爾博士稱(chēng),非洲芒果產(chǎn)區(qū)工蟻特別常見(jiàn),所以這種滅蠅方法對(duì) 非洲特別適用,而且操作起來(lái)不需要多少培訓(xùn)或資金。果農(nóng)只需要找到一個(gè)合適的蟻巢, 用一根繩子將其引向果樹(shù),這樣工蟻很快就可以找到果蠅。范﹒梅爾博士說(shuō),在布基納 法索培訓(xùn)果農(nóng)只需一天時(shí)間,這些果農(nóng)今后不再需要?dú)⑾x(chóng)劑滅蠅,同時(shí),還可以向熱衷 有機(jī)食品的歐洲消費(fèi)者推銷(xiāo)他們的有機(jī)芒果,從而大大提高收入。打個(gè)比方說(shuō),工蟻現(xiàn) 在正向果蠅“全面開(kāi)戰(zhàn)”。
選譯題(缺)
第二部分(缺)
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