油松毛虫性信息素监测量与失叶率及虫口密度的相关性分析

The correlation analysis among sex pheromone trap catch,leaf loss rate and population density of Chinese-pine caterpillar Dendrolimus tabulaeformis

为明确性信息素对油松毛虫Dendrolimus tabulaeformis成虫的监测量与不同危害程度林区失叶率及其幼虫虫口密度的关系,采用棋盘式五点取样法,将失叶率、幼虫虫口密度及成虫监测量两两进行模型拟合。结果显示,幼虫低虫口密度(y_1)、高虫口密度(y_2)与对应的成虫监测量(x_1)、(x_2)呈二次方曲线函数,方程分别为y_1=-0.060x_1~2+6.174x_1-85.753;y_2=0.076x_2~2-3.111x_2+109.844;在幼虫极高虫口密度(y_3)时,成虫监测量(x_3)呈线性递减,方程为y_3=-1.795x_3+214.060;幼虫虫口密度(y)、成虫监测量(x)随着失叶率(z)的增加而增高,但当失叶率超过74%时,幼虫虫口密度呈下降趋势,方程为y=-794.937z^2+1188.218z-308.626;当失叶率超过72%时,成虫监测量也出现下降,二者可以按照方程x=-189.035z^2+272.374z-53.474进行模拟。研究表明,幼虫虫口低密度、高密度与成虫监测量的相关性均显著,极高虫口密度时,成虫监测量呈下降趋势;幼虫虫口密度、成虫监测量均与失叶率呈二次方函数关系。

To evaluate the relationships among sex pheromone trap catch,leaf loss rate and population density of Chinese-pine caterpillar Dendrolimus tabulaeformis in forest with different damage degrees,leaf loss rates,population densities of larvae and catches of adults were investigated by using a five-point chessboard sampling method,and the optimal fitting models of paired-comparisons were conducted.The results showed that,the low（y_1） and high（y_2） population densities of larvae could be estimated by quadratic curves with adults catches（x_1）,（x_2）,and the equations were y_1=-0.060x_1~2＋6.174x_1-85.753 and y_2 = 0.076x_2~2-3.111x_2 ＋ 109.844,respectively.When the larvae population density was very high（y_3）,adults catches（x_3） had a linear reduction in the case,and y_3=-1.795x_3＋214.060.The population density of larvae（y） and adults catches（x） increased with the increase of leaf loss rate（z）,and when leaf loss rate exceeded 74%,larvae population density showed a declining trend and the equation was y =-794.937z^2＋1 188.218z-308.626.When leaf loss rate was higher than 72%,adults catches（x） decreased,and x =-189.035z^2＋272.374z-53.474.The results indicated that the adults catches had significant correlation with the population density of larvae at the low and high population densities;the adults catches decreased at the higher population density.The relationships between both population density and adults catches and leaf loss rate could be described by a quadratic function.