Study on population dynamics and damage of Lygus lucorum Mayr in transgenic Bt cotton

Population dynamics and damage of green leaf bug，Lygus lucorum Mayr，on transgenic Bt cotton are studied in this paper．The results show that the bug num ber on GK-12 is not significantly different from that on its parent，but its degree of leaves damaged by the second generation of green leaf bug is much higher．There are no differences between SGK32 1 and its parent，when the number of green lea f bug and the degree of damaged leaves are compared．The damage index of total leaves on GK-12 is 1．27 times higher than that on SGK32 1．Thus，the damage of green leaf bug to transgenic Bt cotton，GK-12，is upward，while the population and damage on SGK32 1 are controlled in some extent．