松纵坑切梢小蠹防治指标经济阈值及空间分布型的研究

STUDIES ON THE CONTROL INDEX，ECONOMIC THRESHOLD AND SPATIAL DISTRIBUTION OF TOMICUS PINIPERDA

以昆明地区方旺林场、金殿林场、易门县大龙口、小龙口、西冲和裱罗林区为研究基地，定时定位观察云南松纵坑切梢小蠹（ＴｏｍｉｃｕｓｐｉｎｉｐｅｒｄａＬ．）危害程度与云南松经济损失之间的关系。通过统计分析，确定松纵坑切梢小蠹的防治指标：平均虫孔数为０．１８９虫孔／株，林木平均枯死率为０．５２％，平均株枯梢率为４．７４％，有虫株率为５．１４％。

The relationship between the damage level caused by Tomicus piniperda and the economic losses of Pinus yunnanensis was regularly observed on Fangwang forest farm and Jindian forest farm in Kunming and the forests at Dalongkou，Xiaolongkou，Xichong and Biaoluo in Yimen County.By statistical analysis， the controlindex of Tomicus piniperda was determined as follows：the mean insect hole was0．189／tree．the mean rate of withered trees was 0．52 ％．the mean rate of withered branchtops was 4．74％，and the mean rate of infested trees was 5.14％。 By control testing in 473hm2 of pinus yunnanensis forests at Dalongkou，Xiaolongkou， Xichong and Biaoluo，the damage level was already stabilized．The economic-threshold on Fangwang forestfarm was decided as 0．2151 holes／tree. By considering the actual situation of differenthrests， some flexible economic threshold was decided：when the density of insect holesreached 0．3338 × CC÷CYEC（XP），the corresponding withered rate was 0．389＋0．3667 ×CC（Y×EC × P），the mean rate of the withered branch tips was 5．5398＋1．1301 × CC÷（Y×EC 经×P），the mean rate ofinfested trees was 1．63＋14．4821× CC÷（Y× EC × P）， and thecontrol cost and the economic loss were the same so that control measures should betaken. The spatial distribution of Tomicus pinlperda was also determined． It was sug-gested to use sequential sampling to predicate the population changes of Tomicuspiniperda