Forecasting Population Dynamics of Pest by Statistic Discriminatory Principle

According to of two-level discriminatory principle by Fisher rule,the authors analysed the data about the occurrence amount of Aphis gossypii Glover in cotton seeding stage for years of 1982～1994 at Qufu, Shandong province, and then deduced statistic discriminatory inodel.The results tested the pest data showed that the fitting rate is 92.31%, and that accuracy of forecast is right.