为害云南松的纵坑切梢小蠹 (Tomicus piniperda)经济阈值的研究(英文)

经过对纵坑切梢小蠹 (TomicuspiniperdaL .)种群密度和云南松 (PinusyunnanensisFranch .)生长状况的长期、仔细的调查 ,加上改进的回归分析方法 ,得出了为害云南松的纵坑切梢小蠹防治上的经济阈值 :当林木枯死率不超过 0 .5 2 %时 ,自然控制因子能控制纵坑切梢小蠹种群不向高密度方向发展 ,因而可以不必防治。当林木枯死率达到 0 .5 0 % ,对应的枯捎率为 0 .6 1 % ,以及对应的平均每株侵入孔数为 0 .6 6时 ,防治费用和挽回损失价值相当。所以 ,若既考虑到经济上的合理性 ,又考虑到控制其种群不向高密度方向发展 ,当林木枯死率超过 0 .5 % ,对应的枯梢率超过 0 .6 1 % ,以及对应的平均每株侵入孔数超过 0 .6 6时 ,就有了进行防治的必要。本文还给出了各云南松林区可以用来根据自己的具体情况计算出适合自己的经济阈值的公式。

THE STUDY OF THE ECONOMIC THRESHOLD OF TOMICUS PINIPERDA (COLEOPTERA: SCOLYTIDEA) ON YUNNAN PINE

By careful and long period field investigation of the population density of Tomicus piniperda L. and the growth of Yunnan pine(Pinus yunnanensis Franch.), and improved regression analysis, the economic threshold of Tomicus piniperda on Yunnan pine is determined: When the death rate of the trees is not more than 0.52%, the natural control factors can prevent the density of the bark beetle from increasing and no control measure is needed. When the death rate of the trees reaches 0.5%, the corresponding rate of shoots attacked is 0.61% and the mean of invading holes per tree 0.66, the cost for control is equal to the economic loss saved. So, considering both the economic justification and the prevention of the pest density from increasing, when the death rate of the trees is more than 0.5%, the corresponding rate of shoots attacked more than 0.61% and the mean of invading holes per tree more than 0.66, control measure should be taken. The paper also gives formulae for different Yunnan pine forest areas to calculate their own economic threshold according to their special situations.