Bt棉对斑痣悬茧蜂寄主选择及其子代发育的影响

Effects of Bt-cotton on host selection and developmental performances of Meteorus pulchricornis

[目的]评价转Bt基因棉通过非靶标寄主斜纹夜蛾和甜菜夜蛾幼虫对寄生蜂的影响。[方法]分别采用选择性试验和非选择性方法,观察斑痣悬茧蜂对取食Bt棉叶和常规棉叶的斜纹夜蛾和甜菜夜蛾幼虫的产卵选择偏好,并观察子代蜂在不同处理幼虫体内的发育表现。[结果]取食Bt棉叶的斜纹夜蛾幼虫体重与取食常规棉叶的没有显著差异,而取食Bt棉叶的甜菜夜蛾幼虫体重显著小于取食常规棉叶。对斜纹夜蛾幼虫的选择性试验表明,斑痣悬茧蜂未表现出对取食Bt棉寄主幼虫的偏好。[结论]斑痣悬茧蜂子代的历期、存活以及羽化成蜂的体型大小等发育适应度特征,不受寄主幼虫所取食的食料植物的影响。

[Objective] To evaluate the effects of Btcotton on parasitoids mediated by nontarget hosts, Spodoptera litura and S. exigua.[Method] The choice and nonchoice experiments were conducted respectively in laboratory to study oviposition preference of Meteorus pulchricornis for Spodoptera litura and S. exigua larvae fed by Btor regular cotton leaves, and the developmental performances of offspring parasitoids were observed. [Result] The host larvae fed with Bt cotton leaves were not different in body weight from those fed with regular cotton leaves in S. littura, but heavier than those fed with regular cotton in S. exigua. M. pulchricornis did not demonstrate a significant preference between S. litura host larvae fed with Bt and regular cotton leaves. [Conclusion] Parasitoid offspring were not significantly different in development time, survival, and body size of emerged wasps from host larvae that were fed with Bt and regular cotton leaves. The results suggest that M. pulchricornis might not be at risk from attacking nontarget host larvae that feed on Btcotton.