取食Bt棉的棉粉虱对中华草蛉和龟纹瓢虫幼虫存活和发育的影响

Survival and Development of Immature Chrysopa sinica and Propylaea japonicaFeeding on Bemisia tabaci Propagated on Transgenic Bt Cotton

以室内单头饲养方法 ,比较了取食常规棉泗棉 3号、转Bt基因棉GK1 2和新棉 3 3B棉株的棉粉虱对中华草蛉和龟纹瓢虫幼虫存活和发育的影响。①与对照常规棉相比 ,GK1 2上的棉粉虱对中华草蛉幼虫存活和发育没有显著不利影响 ,未成熟期 (幼虫期 +茧 /蛹期 )历期 2 1 3d ,死亡率40 % ,羽化的成虫性比接近 1∶1。②新棉 3 3B上的棉粉虱显著降低幼虫期和茧期中华草蛉的存活率 ,延长其发育历期 ,未成熟期历期 2 4 3d ,死亡率 85% ,羽化成虫全为雌性。③常规棉上的棉粉虱不利于龟纹瓢虫幼虫存活 ,幼虫期死亡率高达 86 7% ;但用Bt棉GK1 2或新棉 3 3B上的棉粉虱饲养 ,幼虫期死亡率分别为 53 3 %和 2 6 7% ,均显著低于对照。④取食Bt棉GK1 2和新棉 3 3B上的棉粉虱 ,瓢虫未成熟期分别为 1 5 5和 1 3 9d,成虫体重分别为 4 0和 4 2mg,差异均不显著 ;但取食新棉 3 3B上棉粉虱的瓢虫死亡率显著低于取食GK1 2上棉粉虱的处理。

Laboratory experiments were carried out to study the survival and development of the Chinese green lacewing Chrysopa sinica and turtle ladybird Propylaea japonica feeding on cotton whitefly Bemisia tabaci on transgenic Bt cotton GK12 and NuCotn 33B. The parental line of GK12, non-transgenic Simian-3 was used as control. The mortality and development during immature period, adult body mass and sex ratio of C.sinica and P.japonica were measured. The results showed that: ①B.tabaci on GK12 had no significant impacts on survival and development of immature C.sinica. It took 21.3d for newly-hatched C.sinica to develop into adult, with a mortality of 40% and sex ratio close to 1∶1. ②B.tabaci on NuCotn 33B negatively affected immature C.sinica. Its immature duration prolonged to 24.3d, with a mortality as high as 85%. All adults developed from the tested larvae were females. ③B.tabaci on non-transgenic cotton plants was proved not suitable for larval survival of P.japonica and 86.7% larvae died. But B.tabaci on the two tested Bt cotton lines GK12 and NuCotn 33B caused only 53.3% and 26.7% larval mortality respectively, which were significantly lower than that in the control. ④ Feeding on B.tabaci on GK12 and NuCotn 33B, the immature duration of P. japonica was 15.5d and 13.9d; and adult body mass was 4.0mg and 4.2mg respectively, showing no significant differences. However, larval mortality of P. japonica feeding on B.tabaci on GK12 and NuCotn 33B differed significantly, B.tabaci on NuCotn 33B caused the lowest mortality.