若虫密度和水稻生育期对稻褐飞虱不同生物型若虫历期、存活及翅型分化的影响

Effects of nymphal density and rice growth stage on nymphal development, survival rate and wing dimorphism of different rice brown planthopper biotypes

观察褐飞虱若虫密度及水稻生育期对褐飞虱生物型Ⅱ、孟加拉型、九龙江型的若虫发育历期、存活、翅型分化的影响表明 ,褐飞虱不同生物型的若虫在水稻不同生育期的发育历期不同 ,以孕穗期最短 ,其次是分蘖期 ,成熟期最长。不同生物型的若虫存活率均与密度呈负相关 ,即随着密度上升 ,存活率下降。在水稻不同生育期 。

This paper dealt with the effects of nymphal density and rice growth stage on nymphal the development,survival rate and wing dimorphism of the rice brown planthopper(BPH)biotype Ⅱ,biotype Bangladesh and biotype cuulong delta.The results indicated that the development durations of nymphs which belong to different biotypes fed on different rice plant stages were different.The shortest deve lopment durations was nymphs fed on rice booting stage ,the tillering stage the second,the maturing stage the longest.Nymphal survival rate of different BPH biotypes had a negative correlation with nymphal density.At different rice growth stages,all BPH biotypes had high brachypterous ratios at different nymphal densities.