棉铃虫对转Bt基因抗虫棉的为害损失及其防治指标研究

Study on Damage of Helicoverpa armigera to Transgenic Bt Cotton and Its Control Index

采用田间接虫试验的方法,研究了江苏沿海地区棉铃虫对转Bt基因抗虫棉的为害损失与防治指标。结果表明,转Bt棉田的残虫量、蕾铃被害率和产量损失均随着接虫量的加大而增加;接虫量与残虫量的关系2代呈对数增长,3、4代表现为直线增长;转Bt棉田棉铃虫2、3、4代的防治指标分别为每百株有3龄左右幼虫15、8和10头或蕾铃被害率依次达1.18%、2.70%和3.30%。

The yield loss of transgenic Bt cotton caused by cotton bollworm (Helicove rpa armigera) and control index of this insect in coastal cotton area of J iangsu province were studied through inoculation experiment. The results indicat ed that the number of remnant bollworm, rate of injured bud and boll, and yield loss all increased as the number of inoculated bollworm increased; the correlati on between the number of remnant bollworm and the number of inoculated bollworm was logarithmic in the second generation, while it was linear in the third and fourth generation; the control index of bollworm in the second, third and fourt h generation was 15, 8 and 10 heads of 3 instar larvae per 100 plants respective ly, or 1.18%, 2.70% and 3.30% of injured bud and boll respectively. 