甜菜夜蛾幼虫对常规棉和转基因棉的取食选择行为

本文研究了甜菜夜蛾Spodoptera exigua幼虫在转基因棉和常规棉上的取食行为反应,以及有/无学习经历对其取食选择的影响及选择行为对蛹重的影响。结果表明,用人工饲料饲养至3龄5、龄的甜菜夜蛾幼虫在常规棉品种33和转基因棉品种33B上、常规棉品种石远321和转基因棉品种SGK321上的取食选择行为除24h内更多的5龄幼虫选择了石远321,在其它时段,幼虫并没有表现出对转基因叶片的规避行为,甚至有些时段更多地选择在转基因叶片上取食;分别用33叶片、33B叶片饲喂至3龄的甜菜夜蛾幼虫进行33和33B的取食选择,以及分别用石远321S、GK321的叶片饲喂至3龄的甜菜夜蛾幼虫进行石远321和SGK321的取食选择均未表现出对转基因棉的规避行为。上述所有处理中,甜菜夜蛾在常规棉上化蛹的蛹重与转基因棉上化蛹的蛹重无显著差异。结果表明,甜菜夜蛾对单价转基因棉33B和双价转基因棉SGK321均未表现出行为抗性。因此,在转基因棉花的害虫治理中要特别关注甜菜夜蛾的防治。

Feeding Behavior of Spodoptera exigua Larvae on Insect-resistant Transgenic Cotton and Non-transgenic Cotton

Feeding choice of Spodoptera exigua larvae between conventional and transgenic cotton,effects of learning on their feeding choice,and pupal weight on transgenic and conventional cotton were investigated.Results showed that 3rd and 5th instars of S.exigua reared with artificial diet did not exhibit avoiding response to transgenic cotton leaves,except that more 5th instars chose the conventional variety Shiyuan321 at 24 h,and even more larvae chose to feed on transgenic leaves.The 3rd instars raised with 33 or 33B cotton leaves did not avoid the transgenic leaves of 33B in choice test between 33 and 33B,and similar result was obtained in choice test with Shiyuan321 and SGK321 cotton leaves.Moreover,in any of above treatments,there was no significant difference in pupal weight between those obtained on the conventional cotton leaves and those on the transgenic cotton leaves.Our study indicated S.exigua larvae did not exhibit behavioral resistance to transgenic cotton 33B and SGK321.Hence,much more attention should be paid to the control of S.exigua in the transgenic cotton field.