Study On The Control Efficiency Of Insect Resistance And Insect Rice Mixed Against Target And Nontarget Insect Pests In Paddyfields

In recent years,the development of Insect-resistant rice lines provides the new strategy for the control of paddyfield pests and has achieved good control efficacy.However,there is no reliable basis for the control efficiency of insect-resistant rice against target pests in long-term planted and the effect on insect-resistant rice against nontarget pests is still not sure.In this study,field experiments were carried out to research the occurring characteristics and population dynamics of the main rice pests including the pests of Chilo suppressalis,Cnaphalocrocis medinalis and Sesamia inferens,the pests of planthoppers and the natural enemies feeding on insect-resistant rice in a pure or mixed cultivation mixed with the parent line rice.Resistance efficiency of insect-resistant rice on C.supperssalis,S.inferens and C.medinalis;the effect on the pests of planthoppers and the natural enemies(Spiders and Cyrtorhinus lividipennis Reuter)were probably conducted.Therefore,the research perhaps provide important scientific basis for the study on the control efficiency of differernt types of insect-resistant rice on the dominant pest species in the field,important scientific data simulating the sustainable application and healthy development of insect-resistant rice.The main results were as follows:1.On the one hand,field experiments were conducted to study the population dynamics of two planthoppers,i.e.,Nilaparvata lugens Stal and Sogatella furcifera Horvath,feeding on Bph resistance rice(Guangliangyou 476)and the parent line of rice(cv.TN1).In 2014,there were significant differences in the population Brachypterous females,Brachypterous males,Brachypterous individuals,Adults,Nymphs subpopulation and Total population of N.lugens fed on insect-resistant rice,mixed processing of 5%-20%insect-resistant varieties better than 100%insect species control treatments and the population Brachypterous females,Brachypterous individuals,Adult subpopulation,Nymphs subpopulation and Total population of S.furcifera fed on insect-resistant rice(Guangliangyou 476).Obviously,it was complicated that the influence of insect-resistant rice on the suction pests such as rice planthoppers and still not sure.On the other hand,the field experiments were carried out to study the population dynamics and damage characteristics of two stem borers,i.e.,the pest of C.suppressalis and S.inferens,feeding on insect-resistant rice.Compared with TN1 rice,insect-resistant rice had significant effect on the population dynamics of C.suppressalis larvae in 2014.In addition,there had a significant difference on percentage of damaged plants of C.suppressalis and S.inferens in 2014.Sense of insect was 5%-20%is significantly lower than the 100%contrast parent strain rate on percentage of damaged plants of C.suppressalis.Simultaneously,there was a significant effect on percentage of head heart and white head plants.Thirdly,Consecutive seasons-long field experiments were conducted to study the resistance efficiency of insect-resistant rice on C.medinalis.The results indicated that insect-resistant rice showed higher resistance to C.medinalis in a pure cultivation.Simultaneously,the results indicated significant differences in the number of eggs and Larvae abundance between insect-resistant rice and the parental control rice.The results may be relevant to the occurrence of C.medinalis and the rice growing situation at that time.Finally,the field experiments were conducted to study the population dynamics of mainly natural enemies,such as Spiders and Cyrtorhinus lividipennis Reuter.There were significant differences in the population abundance of Spiders and Cyrtorhinus lividipennis Reuter in 2014.And there were significant differences in the population abundance of Spiders and Cyrtorhinus fed on insect-resistant rice.What's more,the parental control rice were significantly higher than that of insect-resistant rice in the Spiders and Cyrtorhinus2.In the mixed cultivation field experiment,firstly,there were no significant differences in the population Macropterous females,Macropterous males,Macropterous individuals,Adult subpopulation of N.lugens and Adults of S.furcifera fed on transgenic Bt rice(HH1)mixed with the parent line nontransgenic rice(cv.MH63),but there were significant differences in the abundance of Brachypterous females,Nymphs subpopulation and Total population of N.lugens fed on transgenic Bt rice(HH1)mixed with the parent line nontransgenic rice(cv.MH63),and the abundance of Nymphs subpopulation and Total population of S.furcifera fed on mixed seeding(20%-40%)and 100%transgenic Bt rice was below fed on the parent line nontransgenic rice.Secondly,there were no significant differences in the population abundance of C.suppressalis larvae and S.inferens larvae fed on transgenic Bt rice HH1 mixed with the parent line nontransgenic rice(cv.MH63).In addition,significantly lower percentages of dead heart or white head plants and damaged plants were resulted by C.suppressalis and S.inferens fed on mixed cultivation.What's more,the percentages of dead heart or white head plants of C.suppressalis and S.inferens fed on mixed seeding(5%-40%)and 100%transgenic Bt rice was below fed on the parent line nontransgenic rice.Obviously,mixed cultivation had higher control efficiency of the damagement of the C.suppressalis and S.inferens.Thirdly,the results indicated that transgenic Bt rice showed higher resistance to C.medinalis in mixed cultivation,and the control efficiency was close to 100%.In addition,compared to the 100%parent line nontransgenic rice,there were significant differences in the abundance of eggs and larva in the different mixed seeding.Finally,compared to the 100%parent line nontransgenic rice,the results indicated significant differences in the population abundance of Spiders and Cyrtorhinus lividipennis Reuter in the different mixed cultivations.