The West did not discover the Chinese orange growers' secret weapon until the early 20th century. At the time, Florida was suffering an epidemic of citrus canker and in 1915 Walter Swingle, a plant physiologist working for the US Department of Agriculture, was, the story says, sent to China in search of varieties of orange that were resistant to the disease. Swingle spent some time studying the citrus orchards around Guangzhou, and there he came across the story of the cultivated ant. These ants, he was told, were "grown" by the people of a small village nearby who sold them to the orange growers by the nestful.
The earliest report of citrus ants at work among the orange trees appears in a book on tropical and subtropical botany written by His Han in AD 304. "The people of Chiao-Chih sell in their markets ants in bags of rush matting. The nests are like silk. The bags are all attached to twigs and leaves which, with the ants inside the nests, are for sale. The ants are reddish-yellow in colour, bigger than ordinary ants. In the south if the kan trees do not have this kind of ant, the fruits will all be damaged by many harmful insects, and not a single fruit will be perfect."
The story goes on to say that the long tradition of ants in the Chinese orchards only began to waver in the 1950s and 1960s with the introduction of powerful organic (I guess the author means chemical insecticides. Although most ruit growers switched to chemicals, a few hung onto their ants. Those who abandoned ants in favour of chemicals quickly became disillusioned. As costs soared and pests began to develop resistance to the chemicals, growers began to revive the old ant patrols. They had good reason to have faith in their insect workforce. Research in the early 1960s showed that as long as there were enough ants in the trees, they did an excellent job of dispatching some pests--mainly the larger insects--and had modest success against others. Trees with yellow ants produced almost 20 per cent more healthy leaves than those without. More recent trials have shown that these trees yield just as big a crop as those protected by expensive chemical sprays.
One apparent drawback of using ants--and one of the main reasons for the early scepticism by Western scientists--was that citrus ants do nothing to control mealybugs, waxy-coated scale insects which can do considerable damage to fruit trees. In fact, the ants protect mealy bugs in exchange for the sweet honeydew they secrete. The orange growers always denied this was a problem but Western scientists thought they knew better.
Research in the 1980s suggests that the growers were right all along. Where mealy bugs proliferate under the ants' protection they are usually heavily parasitised and this limits the harm they can do.
Orange growers who rely on carnivorous ants rather than poisonous chemicals maintain a better balance of species in their orchards. While the ants deal with the bigger insect pests, other predatory species keep down the numbers of smaller pests such as scale insects and aphids. In the long run, ants do a lot less damage than chemicals--and they're certainly more effective than excommunication.
本篇按历史顺序写成，含较多时间并要求考生用时间与事件匹配。本篇中出现部分长难句，需要使用句子主干阅读法分析主要信息。
Passage 3 国际机构语言障碍培训方案
难度：高
主要题型：Matching, TFNG, 带选项Summary
大意：介绍大型国际机构语言障碍问题，并给出某机构的3种解决方案，包括使用母公司语言，同传，内部培训等等;最后补充其它机构的另一种方案。典型的问题解决类文章。出题逻辑按照3种主要解决方案进行分类。P-tag技术能够帮助考生进行宏观定位。
以上就是由新东方的雅思阅读名师所发布的2011年6月25日的雅思阅读考题回忆的全部内容，非常详细，类别很多。大家在自己的雅思阅读备考中可以根据自己的实际情况进行适当的参考。
