中文摘要：

为了更全面地评价转Bt基因作物对甜菜夜蛾Spodoptera exigua（Hbner）（鳞翅目：夜蛾科）的影响,在室内研究了甜菜夜蛾低龄幼虫连续6d取食含不同浓度Cry1Ac毒素的人工饲料后转移到不含毒素的饲料上,其生长发育与成虫繁殖的变化。结果表明：低龄幼虫取食含Cry1Ac的饲料6d内,校正死亡率随Cry1Ac浓度的升高以及取食时间的延长而升高。与一直取食不含Cry1Ac饲料的对照相比,取食含Cry1Ac饲料的幼虫体重显著下降;幼虫历期、预蛹期及雌雄蛹期均显著延长,但雌雄蛹重均与对照无显著差异;幼虫化蛹率显著下降,但羽化率与对照无显著差异;成虫产卵前期显著延长,产卵期与对照无显著差异,仅在5μg/g处理下较对照显著延长1.3d;每雌产卵量以10μg/g处理最高（719粒）,但各处理均与对照无显著差异;雌蛾寿命均显著延长,而雄蛾寿命仅在最高浓度80μg/g下显著延长2.4d。这表明,尽管含不同浓度Cry1Ac毒素的饲料对甜菜夜蛾低龄幼虫有明显的生长发育抑制作用或导致死亡,但转移至不含毒素的饲料上取食后,幼虫能迅速恢复生长,顺利化蛹、羽化并产卵。因此,在转Bt基因作物田生长后期,甜菜夜蛾低龄幼虫取食表达Cry1Ac蛋白的组织若能存活并完成世代发育和繁殖,这无疑将增加甜菜夜蛾对Bt作物产生抗性的风险,因此亟需制定Bt作物生态系统中甜菜夜蛾的治理策略。

英文摘要：

To obtain a full-scale assessment of the influences of transgenic Bt crops on the beet armyworm,Spodoptera exigua （Hbner）,larval development and adult reproduction of the S.exigua were examined when early-instar larvae fed on artificial diet containing different concentrations of Cry1Ac toxin for six days and then transferred to non-Cry1Ac toxic diet.The results showed that the corrected mortality of S.exigua significantly increased with increasing of concentration of Cry1Ac toxin and prolonging of feeding time when early-instar larvae fed on artificial diet containing Cry1Ac toxin for six days.As compared to the control fed on non-Cry1Ac toxic diet,larval body weight was significantly decreased when early-instar larvae fed on the artificial diet containing Cry1Ac toxin.Larval duration,pre-pupal duration,male and female pupal duration were all significantly delayed,but male and female pupal body weight were not significantly different from those of control.Percentage of pupation was significantly declined,but the emergence rates were not significantly different from those of control.Pre-oviposition period of adult was significantly delayed,but oviposition period was not significantly different from that of control except that adults with early-instar larvae fed on the 5 μg/g Cry1Ac toxin diet had a significantly longer oviposition period （1.3 d longer）.The highest number of eggs laid per female was observed when the early-instar larvae fed on the artificial diet containing 10 μg/g Cry1Ac toxin,but all the Cry1Ac toxin diet treatments had no significant difference compared with the control.Female longevity was all significantly prolonged,but not male except the treatment of the highest concentration （80 μg/g） of Cry1Ac toxin diet which resulted in a significantly longer longevity （2.4 d longer）.These results indicated that the artificial diet containing different concentrations of Cry1Ac toxin have significant inhibition on the growth and development of S.exigua or directly resulted in death