马尾松毛虫种群动态研究

Study on Population Dynamic of Dendrolimus punctatus Wallker

编著论述了浙江省马尾松毛虫等３种松毛虫的生物学特性，分析了决定马尾松毛虫种群数量的雌性比、产卵量和死亡率３个因子，指出马尾松毛虫雌性比有其遗传因素，其性别早在胚胎发育的卵期已经形成，食料的丰歉与质量、食料树种的不同、不同农药化学防治处理、气温的变化都将影响雌雄虫的比例，产卵量与蛹重有密切关系，蛹重主要受食料数量和质量的影响。１９７９—１９８４年在浙江省余杭长乐林场调查，发现１～２龄幼虫的死亡率对１个世代的种群趋势起重要作用，１—２龄幼虫主要死亡原因是受天敌昆虫蜘蛛、蚂蚁捕食以及捕食引起的惊扰、失踪所致。通过分析与１８个年份６６个世代的统计资料，发现人工释放松毛虫赤眼蜂后，主要卵寄生蜂的总寄生率平均数反而降低了１．７１％，究其原因是由于大量释放赤眼蜂后，削弱了松毛虫黑卵蜂的作用，而赤眼蜂的寄生率又不稳定，其次是松林的强度整枝、大量使用化学农药，使松林生态环境变坏。根据对马尾松毛虫种群发生动态研究，提出了成虫数与４龄幼虫（越冬代属５龄幼虫）的回归方程：第１代马尾松毛虫ｌｏｇ成虫＝１．２４１ｌｏｇ４龄幼虫－３．０１，第２代马尾松毛虫ｌｏｇ成虫＝１．０５７ｌｏｇ４龄幼虫－１．７５，第３代马尾松毛虫１ｏｇ成虫＝１．３?

Bionomics of 3 main pine moths were described and the major factors of female ratio, the number of egg and mortality which influencing the population dynamics of Dendrolimus punctatus Walker were analysied in Zhejiang province. The female ratio was partly influenced by genetic factors and also by the quantity and quality of food trees,pesticides and temperature.Its sex was determined as early as embryoniC period. The number of egg had close relationship with pupal weight which was mainly influenced by quantity and quality of the food trees. It was found that the mortality of the lst-2nd instar larvae played an important role in the population trends of the first generation of D. punctatus Walker in Changle forest farm of Zhejiang province during 197～1984. The mortality was mainly caused by feeding of the natural enemy such as spiders and ants. Analysis of data collected from 18 years and 66 genetations showed that average total parasitism caused by major parasitoids decreased by 1.71% after artificial release of Trichogramma dendrolimi because the action of Telecomus dendrolimusi was crippled by Tr. dendrolimi, meanwhile the parasitism caused by Tr. dendrolimi was unstable. Another cause was intensive prining and large application of pesticides which worsened the environment of pine forest. Studied on the population dynamics of D. punctatus,the regression equation for adult to 4th-instar larva was:1st generation logadult=1.241 log 4th-instar larva-3. 01 2nd generation logadult=1.057 log 4th-instar larva-1. 75 3rd generation logadutl=1.311 log 5th-instar larva-1.03