亚致死剂量吡虫啉和吡蚜酮对褐飞虱生物适合度的影响

 全面评价了亚致死剂量吡虫啉和吡蚜酮对褐飞虱繁殖力和生存力的长期影响。毒力测定结果显示，吡虫啉和吡蚜酮对褐飞虱3龄若虫的LC50分别为42.41 mg/L和396.46 mg/L，吡虫啉毒力约是吡蚜酮毒力的9.35倍。通过建立褐飞虱在吡虫啉和吡蚜酮亚致死剂量（LC30）作用下的生命表，发现褐飞虱在两种药剂处理下生物适合度都有所下降，分别为对照试虫的83.8%和8.4%。吡虫啉处理试虫仅羽化率明显低于对照，而吡蚜酮处理试虫的羽化率、雌虫比例、雌成虫寿命和卵孵化率各参数都明显下降。亚致死剂量的吡蚜酮使褐飞虱日产卵节律和卵孵化高峰都有所推迟，这可能是吡蚜酮对褐飞虱产生取食抑制作用进而导致其生殖器官发育缓慢造成的。

Effects of Sublethal Dose of Imidacloprid and Pymetrozine on Relative Biological Fitness of Brown Planthopper,Nilaparvata lugens

Long-term influences of sublethal dose of imidacloprid and pymetrozine on reproduction and biological fitness of the brown planthopper(BPH) were evaluated.Bioassay results showed that the LC50 values for imidacloprid and pymetrozine were 42.41 mg/L and 396.46 mg/L,respectively,suggesting imidacloprid was approximately 9.35 times more toxic than pymetrozine.The effects of the sublethal dose(LC30) of imidacloprid and pymetrozine on the fitness of the brown planthopper were evaluated by constructing and comparing the life tables.Results revealed that the biological fitness of BPH exposed to imidacloprid and pymetrozine had reduced to only 83.8% and 8.4% of the control,respectively.In imidacloprid treatment,there was only an obvious decline in emergence rate of adult.However,the emergence rate of adult,female adult ratio,female adult duration and eggs hatching rate were conspicuously reduced under pymetrozine treatment.In addition,the egg laying and fecundity fastigium of BPH exposed to sublethal pymetrozine were postponed compared to the control,which is probably correlated with the delayed development of genitalia caused by pymetrozine’s feeding inhibition effects.