Synergistic Effect of Transgenic Cotton with Bt-gene and Insecticide on the Activity of Prodenia litura(Fabricius)

[Objective]The aim of study was to provide scientific basis for the comprehensive control of Prodenia litura.[Method]With transgenic cotton with Bt-gene Sukong 103 and common cotton Sumian 12 as tested materials, the effects of combined feeding of 2 cottons with 4 insecticides on the growth and development of P.litura and their insecticide susceptibilities were compared.[Result]As for the susceptibilities of 3 instar larva P.litura fed continuously for 3 generations to fenvalerate,methomyl,trichlorfon and Bt WP, the susceptibilities of larva of that fed by Sukong 103 were 0.54,0.61,0.80 and 0.48 times of that fed by Sumian 12.When the larva were fed with Sukong 103 and Sumian 12 resp.immersed insecticide,the susceptibilities of Sukong 103 to insecticide was were more higher than that of Sumian 12.Compared with the larva fed with Sumian 12,the survival rate of the larval fed with Sukong 103 was decreased by 30%,the larval duration was 9.6 days longer,and the instar number increased from 6 instars to 8 instars,the specific activities of acetylcholinesterase and carboxylesterase in larva were obviously higher.[Conclusion]Combination of Sukong 103 and chemical insecticide can make susceptibilities of P. litura be stronger.