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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,第二代灰之,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。
Based on the results of several years, this paper analyzes the dynamics of Dendrolimus punctatus in order to understand its certain rules and provide the basis for the measurement and prevention. Although the period of occurrence of this pest varies from place to place, in the same area, the amplitude of the occurrence of each state of insects in each year is not large. According to the occurrence of the hazard, the pest occurrence areas can be divided into three categories: (1) the safe mountain areas, (2) the shallow mountain incidental areas, and (3) the rampant hills. Dividing the occurrence areas according to this situation is of great practical significance for the prevention and control of this species of pests. The pest population changes in the seasons, has its own regularity. The number of the fourth instar larvae in the year is the largest in the first generation, the second generation is gray and the fewest in the winter. There is no obvious correlation between the number of each generation and the number of its next generation. The number of the next generation mainly depends on the mortality of 1 to 3 instars larvae, the mortality rate is small, the number of next generation is large, On the contrary, there is little evidence that we can see that the number of fourth-instar larvae in the modern era is the more reliable basis for determining the number of each generation. The number of overwintering generations, for the next spring over the winter on behalf of a decisive role, due to the general overwintering mortality is not. Predict the number of occurrence, on the above facts, we must pay attention. Affect the occurrence of Masson pine caterpillars factors, mainly climate, food and natural enemies, but to a larger range of climate, food and natural enemies only in some areas.