第一部分

英译汉必译题

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.

天之聪网校参考译文：

如同其他地区一样，非洲芒果产区也饱受果蝇困扰，果蝇泛滥使芒果减产达40%左右。事实上，非洲芒果中果蝇屡见不鲜，美国已下令对非洲芒果实施进口禁令，保护本国果园免受果蝇之害。但与此同时，非洲果农面对果蝇侵袭几乎无计可施。化学杀虫剂十分昂贵，即便买得起，杀虫剂灭蝇效果也不理想，因为当果农发现有果蝇后再喷洒往往为时已晚。

农业科学家也曾经尝试利用寄生蜂来防治果蝇虫害。但是，最常见的寄生蜂仅能杀死二十分之一的果蝇，躲过一劫的果蝇则继续为非作歹。还有一种方法是利用果蝇诱捕器，通过性诱剂引诱果蝇达到灭蝇目的。但是，这种诱捕器也是成本不菲。所以，大部分果农干脆趁芒果未全熟时提早采摘，这样果蝇危害性是小了，但是芒果也卖不出好价钱。

但是，如果芒果树上有大量工蚁安家的话，果农就彻底省心了。由范﹒梅尔博士和同事在贝宁的几家果园开展的一项调查显示，每三十个芒果中，工蚁较多的芒果树所产芒果果蝇蛹还不到1个，而没有工蚁的芒果树所产芒果果蝇蛹达到77个。调查发现，工蚁觅食果蝇及其他害虫，灭蝇效果很好。

利用工蚁防治病虫害的做法在中国及其他亚洲国家已有数百年历史，澳大利亚也已予以采用。但是，范﹒梅尔博士称，非洲芒果产区工蚁特别常见，所以这种灭蝇方法对非洲特别适用，而且操作起来不需要多少培训或资金。果农只需要找到一个合适的蚁巢，用一根绳子将其引向果树，这样工蚁很快就可以找到果蝇。范﹒梅尔博士说，在布基纳法索培训果农只需一天时间，这些果农今后不再需要杀虫剂灭蝇，同时，还可以向热衷有机食品的欧洲消费者推销他们的有机芒果，从而大大提高收入。打个比方说，工蚁现在正向果蝇“全面开战”。

选译题（缺）第二部分 （缺）