【摘要】 <正> 研究昆虫种群的空间结构可分为下列三个层次,即田间集团分布,地理分布和猖獗区的分布。伊藤正春(1959)曾提出这三种空间结构层次与时间上的联系,即(1)世代内构成种群的个体在其栖息场所内的分布,称为Intra-generation range。(2)世代间种群的季节性生境转移所造成的水平分布及垂直分布,称为Generation range。(3)年代间种群猖獗的常发区或偶发区的地理分布,称为Inter-generation range。更多还原

【Abstract】 1. The group distribution patterns of lavae of army worm in eight plots of rice fields were investigated by the method of freguent distribution. The results showed that the distribution patterns fitted a lot of the negative binomial distribution, little Neyman distribution and not Poisson distribution.2. Investigetions of 1214 times in a number of counties in south China on the geographical distribution of outbreak regions of army worm have made during 23 years (1958-80). Index of dispersal c was colculated. It showed that the geographical distribution of outbreak areas of army worm was significantly aggregation and index of dispersal c may be used as a quite sensitive target indicating the outbreak level of aggregation of population number in diffrent years. The larger value of c indicates more aggregation of the population number and serious damage bccurrenca, and vice versa.3. The aggregation indices Iδ, IB, CA were calculated and the results also showed that geographical distribution of army worm is obviously aggregated. These indices can also be used to express the absolute quantity of aggregate level. , On the other hand, they can be used to test the distribution of population of army worm in the fields, in some fields, the conclusion can not be obtained with the method of conformity test of distribution pattern, but the correct conclusion can be obtained by means of the aggregate indices.4. Comparsion the value of Taylor’s index, b for field distribution and for geographic distribution in outbreak zone have been made index of 2.3353 from the data of the field distribution, and index of 2.5881 from that of geographic distribution was obtained respectively. Both are very close. It can be proved that the geographic distribution of outbreak zone is the macrograph of the field distribution. Conversely, the field distribution is the projection of the geographic distribution. The values ofα, β of m-m regression between field distribution and geographic distribution have also been campared. The results showed that both α, one bigger than zero and β bigger that unit. The reasons of aggregation include the characteristic of reproduction and spread of army worm, and also include the effects from the different environmemtal conditions.更多还原