噻虫嗪对白背飞虱试验种群繁殖力的亚致死效应
Sublethal effects of thiamethoxam on the fecundity of lab populations of white-backed planthopper Sogatella furcifera(Horváth)

为探究噻虫嗪对白背飞虱的亚致死效应，采用稻茎浸渍法以噻虫嗪亚致死浓度LC10和LC25胁迫白背飞虱3龄若虫，测定了F0代和F1代若虫的存活率、雌成虫寿命和产卵量，并组建了F1代种群相对适合度生命表。结果表明，经噻虫嗪亚致死浓度胁迫后，F0代白背飞虱若虫的发育历期延长，存活率降低，并且LC10处理组的F0代雌成虫寿命比对照组显著延长，而成虫产卵量显著变化；F1代的若虫发育历期比对照组显著延长，且产卵量有所减少，LC10处理组雌成虫产卵量比对照组减少了22.24，LC25处理组比对照组减少了69.96，且差异显著；LC10和LC25亚致死浓度处理后F1代的种群增长趋势指数均下降，种群相对适合度分别下降了0.12和0.36。研究表明，噻虫嗪亚致死浓度胁迫均可抑制白背飞虱的种群增长。
To figure out the sublethal effects of thiamethoxam on white-backed planthopper Sogatella furcifera(Horváth),the 3rd instar nymphs were exposed to the two sublethal doses LC10 and LC25 of thiamethoxam with the rice stem dipping method.The survival rates of F0 and F1 nymphs,the longevity and fecundity of F0 and F1 adults were investigated.The life-table of F1 generation was constructed.The results showed that both sublethal doses could prolong the developmental duration and decrease the survival rate of F0 nymphs.In addition,F0 female adults treated by LC10 of thiamethoxam had significant longer lifespan compared to that of the control,and the fecundity of adults had no difference from that of the control.As for F1 generation,both treatments significantly prolonged the developmental durations of nymphs.The oviposition amount of adults treated with LC10 of thiamethoxam was 22.24 eggs less than that of the control,while that of the adults treated with LC25 of thiamethoxam was significantly 69.96 eggs less than that of the control.Both sublethal doses of thiamethoxam resulted in declining population trend index.The relative fitness of F1 generation treated by LC10 and LC25 of thiamethoxam was reduced by 0.12 and 0.36,respectively.The results indicated that the sublethal dose of thiamethoxam had negative effect on S.furcifera.