这些天看奥运转播,尤其是自行车路赛和女子马拉松时,总是惊艳于北京的绿.
这篇纽约客文章似乎提供了一些线索,Bug Wars(虫子大战), by Richard Rayner.
For years, a blight had ravaged nearly all the deciduous trees in Beijing, leaving the branches naked and ugly. Civic leaders were worried, in the run-up to the Games, what the bare trees would say about their city’s environmental problems. So, a couple of years ago, they approached the Beijing Forestry University and the Chinese Academy of Forestry and asked if a way could be found to put the leaves back. The Chinese experts—many of whom had worked with or studied under Heliövaara—turned to the Finn for assistance. Heliövaara signed on, and, after he and the scientists discovered that the larvae of moths and sawflies were causing the problem, he helped launch a project called Green Beijing.
好几年了,北京的落叶树好像总是不长叶子,光秃秃的树枝很难看. 奥运会将近, 领导门很着急, 干巴巴的树枝会让人对北京的环保问题有什么样的看法? 两年前, 领导向北京林学院和林业大学求救,能不能把叶子还给北京的树? 这些中国林业学家很多曾经从师于芬兰昆虫学家 Heliövaara, 他们向Heliövaara求助, Heliövaara一口答应. 他和北京的学者门发现原来是蛾子和锯蜂的幼虫吃光了这些树叶后,开始了一名为”绿色北京”的项目.
Heliövaara的方案是猎取一双公母蛾子,让他们交配产卵, 等卵变成幼虫(毛毛虫?)之后,再让一种特别的马蜂去”感染”幼虫,就是在幼虫体内产卵.幼虫变成茧子后再把这个寄生茧子绑在受害的树上.最后破茧而出的就会是马蜂而不是蛾子,这些马蜂可以开始消灭附近树上的蛾子幼虫.
Last summer, Green Beijing had a successful trial run: leaves returned to deciduous trees in the control area within weeks. So millions more parasite-infected cocoons were prepared, and in May of this year, and again in July, an army of more than a thousand Chinese students, supervised by entomologists, went from tree to tree all over Beijing, putting cocoons on two hundred thousand trees.
去年夏天,”绿色北京”项目试点成功: 在几个星期之内实验范围内的树就开始长出了新叶. 于是几百万个有寄生马蜂的蛾茧被精心”制造”出来,今年五月和七月,由一千多名学生组成的大军在昆虫学家的指导下,在遍布北京的两千棵树上”植入”这些蛾茧.
是不是说北京今年的马蜂会特别多? 
