杀虫剂对小菜蛾实验种群的影响

Effect of pesticides on the laboratory population of Plutella xylostella (L.)

用生物农药８０１０（１００亿活芽孢／克）５００、１０００、２０００、４０００倍液和２１％灭杀毙乳油（６％氰戊菊酯＋１５％马拉硫磷）１０００、２０００、４０００倍液在２７℃恒温条件下对小菜蛾进行卵期处理。各处理对小菜蛾的卵孵化率无影响，但对其幼虫的死亡率则影响较大。不同处理间小菜蛾的发育速率和成虫产卵量存在着较大的差异；各项种群参数，即每雌平均产雌量（Ｅ）、净增殖率（Ｒ０）、世代平均历期（Ｔ）、内禀增长能力（ｒｍ）、周限增长率（λ）、双倍时间（ＤＴ）等也存在差异。

The eggs of DBM [diamondback moth, Plutella xylostella (L.)] were treated at the constant temperature of 27℃ with 8010 wp. 500x, 1000x, 2000x, 4000x and 21% MSB EC (6% Fenvalerat+15%Malathion +Synorgists) 1000x, 2000x, 4000x respectively. All treatments had no effect on the hatching of eggs, but had considerable effect on mortality of larvae, and the effect on the development rate and the number of eggs laid were different. The laboratory population parameters of DBM, namely average eggs per female (E), net reproductive rate (R 0), mean generation duration (T), innate capacity for increase (r m), finite rate of increase (λ) and doubling time (D T) were different in all treatments.