稻飞虱自然种群变动与药剂防治技术研究

模拟稻飞虱迁入和田间系统调查结果表明：褐飞虱增殖倍数与迁入基数关系不显著，而与水稻生育期有密切关系，最高虫量在孕穗至齐穗期。白背飞虱最高虫量在分蘖末期，其数量和结构变化与水稻生育期无明显关系。若虫是为害水稻的主要虫态。药剂防治试验结果表明：选用虱纹灵防治稻飞虱可兼治纹枯病，优于叶蝉散和甲胺磷。防治1次以水稻孕穗初期施药（均在低龄若虫高峰时）为好。防治２次以始穗期为适期。

Studies on the Natural Population Dynamlcs of Rice Planthoppers and Their Cbemical Control Tech-niques.

A simulated test for immigrated rice planthoppers and a serial investigations showed that themultiplication rate of brown planthopper Nilaparvata lugens Stal did not bear relationship to the immigrantnumber,but closely related to the growing stage of rice plants.The maximum numbers of brown planthop-per occurred in rice booting to late heading.For white-backed planthopper,Sogatella furcifera(Horvath)the maximum numbers occurred in late tillering stage,and the dynamics of its natural population and com-position showed insignificantly related to the growing stage of rice plant.The nymphal stage was impor-tant in damaging the rice plants.The results of chemical control test showed that compound pesticide Shi-wenling was more effective than isoprocarb and methamidophos in controling rice planthoppers.The appli-cation at early booting stage was proved to be better than that at early heading stage in single applicationplots,but a second application at the early heading stage was suitable in two-application plots.