有机稻田褐稻虱种群动态及天敌作用分析

为组建有机稻田褐稻虱Nilaparvata lugens(Stl)种群生态控制系统,系统调查实施有机耕作1年后褐稻虱种群动态,并应用生命表技术评价自然天敌的作用。结果表明,有机晚稻田中褐稻虱种群发生2个世代。高峰期分别为9月底~10月初、10月下旬,平均百丛达502.3,164.5头,种群增长率为常规稻田的31.76%。水稻移栽后天敌数量迅速回升,有机稻田中蜘蛛、捕食性天敌、寄生性天敌分别比常规稻田增长66.10%,166.67%,44.24%。将各类天敌作用相加,以"捕食及其它"、"寄生"对褐稻虱种群的控制作用最强,其EIPC值均显著高于常规稻田相应天敌因子EIPC。

Population dynamics of brown planthopper, Nilaparvata lugens, and effects of natural enemies in organic rice field

To construct the ecological management system of BPH (back planthopper) Nilaparvata lugens (Stl) population, the dynamics of BPH population was investigated systematically in organic rice field, and the effects of natural enemies were studied by the means of life table technique. The results indicated that the BPH population occurred two generations in organic rice fields. The two peak periods were from the end of September to early October and the third ten days of October, respectively, in which the BPH population size was 502.3 individuals per 100 plants,and 164.5 individuals per 100 plants, respectively. The increasing rate of BPH in organic rice field was 31.76% of that in conventional rice field. The natural enemies increased rapidly after rice planted. Spiders, predators and parasites in organic rice field increased 66.10%, 166.67% and 44.24% than those in conventional rice field, respectively. To add up the effects of all kinds of natural enemy factor, predators and parasites had significant influence in controlling BPH, which EIPC value in organic rice fields were higher than that in conventional one.