---

作 者 ：萧刚柔 严静君 徐崇华 丁道模 沈光普 黄傅威

期 刊 ：林业科学 1964年 9卷 3期 页码：201-220

关键词：马尾松；

摘 要 ：本文根据几年来研究结果,就马尾松毛虫发生动态进行初步分析,以便了解其一定规律,而为测报及防治提供依据。本种害虫发生时期虽因地而异,但在同一地区,其各虫态各年中发生期的变幅,并不算大。根据发生危害情况,可将本种害虫发生地区分为三类,即(1)深山安全地区,(2)浅山偶发地区,及(3)丘陵猖獗地区。把发生地区按照这一情况划分,对防治本种害虫,颇有实际意义。本种害虫种群数量季节变动,有其一定规律性。一年中第四龄幼虫发生数量以第一代最多,第二代次之,越冬代最少。各世代数量的多少,对于其下一代数量的变动,并无显明的相关性存在,下一代数量多少,主要以其1一3龄幼虫死亡率大小为转移,死亡率小,下一代数量多,反之则少,由此可知当代第四龄幼虫数量是决定各该代数量多少的比较可靠的依据。越冬代数量多少,对于次年春季越冬代大发生有决定性作用,因一般越冬死亡率不大。预测发生数量,对上述事实,必须加以重视。影响马尾松毛虫发生的因素,主要有气候、食料及天敌,而以气候影响范围较大,食料及天敌则只有在局部地区起作用。

Abstract:The present investigation was made in the course of three years (1961—1963). Thirty-two plots,each of 2—3 mou,in Pinus massoniana stands were selected for esti- mating the fluctuation of population of this serious pest.The estimations comprised of several items,such as sex ratio,fecundity,mortality and others. Based on the results of observations,it was found that in the hilly areas of Kiangsf Province,the outbreak of this pest seemed to be of intermittent epidemic type.The out- break intensity,as measured by the number of generations between two successive out- breaks,varied from 2 to 3 or more generations. The population clensity varied from generation to generation. As a rule, the first generation had the highest population density, and the overwintering generation the low- est. The population density of each generation was mainly decided by the mortality of the first three instar larvae. No close relationship between populations of two successive generations was found. In those areas where there were 2—3 generations a year,the larvae of the second generation when developing to fourth instar,differentiated into two groups.The larvae of the one group went into diapause right away and those of the other continued to de- velop and overwintered as 3rd instar larva in the third generation.The number of larvae in each of the two groups varied with environmental conditions.The ecological significance of this phenomenon should be studied further.But based on the results of examinations,it was found that this phenomenon exerted no influence on the population change of the overwintering generation. Besides the human effect,there were three factors affecting the population changes, namely the climatic,food and natural enemy factors.The effect of climate on popula- tion fluctuation was found to have been greater than that of the food or of the enemies. In Kweichi,Kiangsi,the precipitation in May and in August exerted a decisive effect on the occurrence of outbreak in a year.The food factor affected the population change only in certain localities where the pine needles were completely consummed by this pest. The natural enemies exercised a great effect on the population immediately after the collapse of the outbreak. The number of generations completed in one year varied from the south to the north.There were 3—4 generations in Canton,Kwantung Province,while in Hsinyang, Honan Province only 2—3 generations a year.The highest fecundity was 881 eggs per female with an average of 681.5 eggs.But in general,a female laid only 200—300 eggs.

---