落叶松腮扁叶蜂自然种群生命表分析

落叶松腮扁叶蜂是兴安落叶松重要食叶害虫，自1998年以来在内蒙古大兴安岭林区成灾，1998—2002年间研究了该虫种群自然消长规律。将落叶松腮扁叶蜂种群按其生长发育顺序划分为卵期、危害幼虫期、滞育幼虫期、蛹期和成虫期5个阶段，把各阶段的作用因子划分为相对独立的状态，根据田间调查及室内实验观察，记录各阶段的存活数，组建了5个世代的生命表，1个平均生命表。分析表明：平均种群趋势指数为4．56。其中危害期幼虫相关系数r值为0．6857，回归系数b值为0．2221，滞育幼虫r值为0．8965，b值为0．6165。滞育幼虫期为落叶松腮扁叶蜂种群生活过程中的关键阶段。滞育幼虫期的自然消亡是影响整个种群动态的关键因素。突然降温等灾害性天气对发生期各虫态影响明显。重要因子分析表明，影响落叶松腮扁叶蜂自然种群的重要因子是天敌、气候、食料等。

Analysis on the life table of natural population of Cephalcia lariciphila

From 1998 to 2002,the natural population life table of Cephalcia lariciphila was studied in Yakeshi,Inner Mongolia.Based on the data obtained from field investigation and lab observation,natural population life tables and one average life table were constructed in five years.According to the sequence of its growth and development,the population of Cephalcia larciphila was divided into five stages such as eggs,active larvae,diapausing larvae,pupae and adults.The affecting factors in each stage were divided into relatively independent status.The results showed in the forest the index of population tendency was 4.56,the coefficient value (b) for diapausing larvae was r=0.8965,b=0.6165,that for the larvae at feeding stage was r=0.6857,b=0.2221.That showed the natural fluctuation of population in diapausing larvae stage was the key factor.The disastrous weather such as sharp drop in temperature significantly influenced the survival of Cephalcia larciphila.The analysis of important factors showed that the natural enemies,climate and food were the important factors affecting the natural population of Cephalcia larciphila.