Bug Wars
by Richard Rayner August 25, 2008
published in the New Yorker
Kari Heliövaara, head of forest entomology at the University of Helsinki, was recently part of a team hired to prevent an ongoing eco-catastrophe before the Olympics in Beijing. For years, bugs has ravaged nearly all the deciduous trees in Beijing, leaving the branches "naked and ugly". Civic leaders were worried about the environmental image that the country would give during the Olympics and therefore decided to act as fast as possible.
Chinese experts turned to Heliövaara for assistance, and he soon discovered that the larvae of moths and sawflies caused the problem. He soon launched a program called 'Green Beijing'.
Chemical control was possible but ecologically not very friendly, and biological control was much more efficient. Biological control means, in this case, "rearing parasites that attack only the defoliating pests".
This is very challenging because you have to use the right kind of parasite in order to get rid of the larvae. In order to create the 'parasite', you have to capture a female moth, a male moth, make them mate and infest their eggs with the parasite. When the cocoons are put back on the trees, only the parasite survives and then attacks the larvae you are trying to get rid of.
But given the tight deadline of the summer Olympics, more labs were needed. The Chinese government built 20 buildings, in and out of the city in order to create the larvae that would get rid of the moths.
Last summer, Green Beijing had successful trials and decided this year, in May, to release the larvae in all of Beijing. In a matter of weeks, about 20 thousand parasites emerged from each cocoon, killing the sawfly and moth larvae.
Prof. Heliövaara has watched the Olympics on TV, and says he is very happy because Beijing now looks green
by Richard Rayner August 25, 2008
published in the New Yorker
Kari Heliövaara, head of forest entomology at the University of Helsinki, was recently part of a team hired to prevent an ongoing eco-catastrophe before the Olympics in Beijing. For years, bugs has ravaged nearly all the deciduous trees in Beijing, leaving the branches "naked and ugly". Civic leaders were worried about the environmental image that the country would give during the Olympics and therefore decided to act as fast as possible.
Chinese experts turned to Heliövaara for assistance, and he soon discovered that the larvae of moths and sawflies caused the problem. He soon launched a program called 'Green Beijing'.
Chemical control was possible but ecologically not very friendly, and biological control was much more efficient. Biological control means, in this case, "rearing parasites that attack only the defoliating pests".
This is very challenging because you have to use the right kind of parasite in order to get rid of the larvae. In order to create the 'parasite', you have to capture a female moth, a male moth, make them mate and infest their eggs with the parasite. When the cocoons are put back on the trees, only the parasite survives and then attacks the larvae you are trying to get rid of.
But given the tight deadline of the summer Olympics, more labs were needed. The Chinese government built 20 buildings, in and out of the city in order to create the larvae that would get rid of the moths.
Last summer, Green Beijing had successful trials and decided this year, in May, to release the larvae in all of Beijing. In a matter of weeks, about 20 thousand parasites emerged from each cocoon, killing the sawfly and moth larvae.
Prof. Heliövaara has watched the Olympics on TV, and says he is very happy because Beijing now looks green
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