Effects of Bt rice on the number and hatch rate of planthopper eggs and their attack by natural enemies in paddy fields.

In order to assess the effects of transgenic rice on non-target pests and their natural enemies after release,a field study was conducted over 2 years to determine the effects of transgenic Bt rice on population dynamics,hatchability and mortality of planthoppers eggs and their attack (predation and parasitism) by natural enemies at the Experimental Farm of Zhejiang University and the Experimental Farm of China National Rice Research Institute in 2008 and 2009. The results showed that the trends of population dynamics and hatchability of planthopper eggs and their predation and parasitism rate were almost the same on the three different rice lines (Kemingdao1,Kemingdao2 and Xiushui11) at two experimental farms in 2 years. Moreover,the peak of number of planthopper eggs on all the three rice lines lasted about two weeks in paddy fields. However,no uniform trend of the mortality of planthopper eggs was found on the three rice lines at two experimental farms in 2 years. Furthermore,no significant difference was found on population dynamics,hatchability and mortality of planthoppers eggs and attacks (predation and parasitism) by natural enemies among the three rice lines in general (P0.05). We so conclude that Bt rice does not significantly affect the eggs of planthoppers in paddy fields.