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...