稻粉虱为害损失测定与经济阈值

Damage and economic threshold of rice whitefly

稻粉虱Ａｌｅｕｒｏｃｙｂｏｔｕｓｉｎｄｉｃｕｓ是福建新发生的一种害虫．根据虫量和产量的关系，结合现行稻谷价格、产量水平、防治费用等因素，进行了稻粉虱为害损失的测定，确定允许为害损失率．同时，建立了经济阈值模型：ＥＴ＝１００×Ｃ×Ｆ／（０．０８５１×Ｐ×Ｎ×ＥＣ）＋１７９．４３（早稻穗期）；ＥＴ＝１００×Ｃ×Ｆ／（０．０７４６×Ｐ×Ｎ×ＥＣ）＋１６０．４７（晚稻孕穗期）．根据经济阈值模型，制定出不同产量水平的经济阈值．

Rice whitefly ( Aleurocybotus indicus ) is a new insect pest on rice in Fujian Province. In this paper, the yield losses of rice caused by rice whitefly A. indicus have been investigated. Based on the relationship between rice whitefly population and rice yield loss, combined with rice price, yield level and cost of control, the economic tolerance to the pest was determined, and the models of economic thresholds of rice whitefly were set up as follows: ET= 100×C×F/(0.0851×P×N×EC)+179.43 (earing stage of the first season rice); ET= 100×C×F/(0.0746×P×N×EC)+160.47 (booting stage of the second season rice). According to the models, the economic thresholds of rice whitefly at different yield levels were determined.