Fall armyworm has invaded China and colonized its populations in tropical and sub-tropical regions of South China since December 2018.Chemical spray has been widely used to control the pest,which shall lead to resista...Fall armyworm has invaded China and colonized its populations in tropical and sub-tropical regions of South China since December 2018.Chemical spray has been widely used to control the pest,which shall lead to resistance evolution.In this research,we collected five populations of the pest from Yunnan,Hainan,Tibet,and Fujian of China,and tested their susceptibilities to pyrethroid,organophosphorus,oxadiazine,diamide,antibiotics and other types of insecticides(14 insecticides totally)in the laboratory.Based on the susceptible baseline published from the previous studies,the resistance ratio was 615-1068-fold to chlorpyrifos,60-388-fold to spinosad,26-317-fold to lambda-cyhalothrin,13-29-fold to malathion,9-33-fold to fenvalerate,8-20-fold to deltamethrin,3-8-fold to emamectin benzoate and 1-2-fold to chlorantraniliprole,respectively.The median lethal concentration(LC_(50))of other six insecticides without the susceptible baselines was 148.27-220.96μgmL^(-1) for beta-cypermethrin,87.03-128.43μgmL^(-1) for chlorfenapyr,16.35-99.67μgmL^(-1) for indoxacarb,10.55-51.01μgmL^(-1) for phoxim,7.08-8.78μgmL^(-1) for M-EBI(the mixed insecticide of emamectin benzoate and indoxcarb)and 1.49-4.64μg mL^(-1) for cyantraniliprole.This study can be helpful for chemical control as well as for resistance monitoring and management of the pest in China.展开更多
ATP-binding cassette transporter C2(ABCC2)is known to be a receptor for Bacillus thuringiensis(Bt)toxins in several lepidopteran insects.Mutations in the ABCC2 gene have been genetically linked to field-evolved resist...ATP-binding cassette transporter C2(ABCC2)is known to be a receptor for Bacillus thuringiensis(Bt)toxins in several lepidopteran insects.Mutations in the ABCC2 gene have been genetically linked to field-evolved resistance to the Cry1 F toxin from Bt in Spodoptera frugiperda.Here we generated a SfABCC2 knockout strain of S.frugiperda using the CRISPR/Cas9 system to provide further functional evidence of the role of this gene in susceptibility and resistance to Cry1 F.Results from bioassays showed that the SfABCC2 knockout S.frugiperda strain displayed 118-fold resistance to Cry1 F compared with the parental DH19 strain,but no resistance to Vip3 A toxin from Bt.These results provide the first reverse genetic evidence for SfABCC2 as a functional receptor for Cry1 F.展开更多
The fall armyworm(FAW)Spodoptera frugiperda,which originated in the Americas,is advancing across China and threatening the nation’s maize crops.Currently,one widely used tool for its control is genetically modified(G...The fall armyworm(FAW)Spodoptera frugiperda,which originated in the Americas,is advancing across China and threatening the nation’s maize crops.Currently,one widely used tool for its control is genetically modified(GM)Bacillus thuringiensis(Bt)maize.Sufficient content of Bt protein in appropriate plant parts is crucial for enhancing resistance against insect pests.In this study,we conducted a systematic investigation of Cry1 Ab levels in Chinese domestic GM maize DBN9936,which has recently obtained a biosafety certificate,and evaluated its efficacy against FAW.Quantification of expression levels of Cry1 Ab,via ELISA,indicated a spatio-temporal dynamic,with significant variation of mean Cry1 Ab,ranging from 0.76 to 8.48μg g-1 FW with the Cry1 Ab protein level ranked as:V6-V8 leaf>R1 leaf>R4 leaf>R1 silk>VT tassel>R4 kernel.Among the nine locations,the Cry1 Ab levels in DBN9936 of the Xinxiang,Langfang,and Harbin fields were significantly lower than those from Wuhan and Shenyang,and were slightly,but not significantly lower than those from the other four fields.Furthermore,the artificial diet-Cry1 Ab mixture and plant tissue feeding bioassays revealed that DBN9936 has high efficacy against FAW.The insecticidal efficacy of different tissues against FAW larvae reached 34-100%with a descending order of lethality as follows:VT leaf>R4 leaf>R1 husk>R1 silk>VT tassel>R4 kernel.Taken together,our results showed that Bt-Cry1 Ab maize DBN9936 has potential as a promising strategy to manage FAW.展开更多
The fall armyworm(Spodoptera frugiperda)is a major agricultural pest native to the Americas.It is widely distributed throughout the Western Hemisphere.It damages crops such as maize,wheat,rice,sorghum,cotton,herbage a...The fall armyworm(Spodoptera frugiperda)is a major agricultural pest native to the Americas.It is widely distributed throughout the Western Hemisphere.It damages crops such as maize,wheat,rice,sorghum,cotton,herbage and various weeds,and reportedly feeds on more than 300 species(Montezano et al.2018).Fall army wo rm is a typical lepidoptera pest and goes through four life stages:egg,larva,pupa and adult Adults can lay eggs between 1000 and 2000 and complete a life cycle within about 30 days,reproducing at a fast speed.There are two biotypes of fall armyworm:Corn-biotype(C-strain)and Rice-biotype(R-strain).展开更多
The fall armyworm,Spodoptera frugiperda,which destroys many economic crops such as rice and maize,has recently invaded China.Insect viruses as biological control agents play important roles in killing pests.One potent...The fall armyworm,Spodoptera frugiperda,which destroys many economic crops such as rice and maize,has recently invaded China.Insect viruses as biological control agents play important roles in killing pests.One potential viral insecticide is the environmentally highly infective and virulent densovirus.We successfully rescued Junonia coenia densovirus(JcDV)using its infectious clone in different insect cell lines and larvae of three insect species.Results showed that the lysate of cultured insect cells transfected by the JcDV infectious clone killed the 2 nd instar S.frugiperda.The LD50 of homogenate from JcDV-infected Spodoptera litura to the 2 nd instar S.frugiperda(1.76×10^(8)viral genome copies per larva during 10 d post infection)was higher than that of the 2 nd instar S.litura(7.39×10^(7)Jc DV genome copies)or Helicoverpa armigera larvae(9.71×10^(7)JcDV genome copies).The LT50 of the S.litura homogenate(2.60×10^(9)viral genome copies each larva)to the 2 nd instar S.frugiperda was 6.96 d,longer than that of the S.litura(6.18 d)or the 2 nd instar H.armigera(5.94 d).JcDV could infect the fat body of H.armigera,but not S.frugiperda or S.litura.Although JcDV can infect all three lepidopteran species,their susceptibility to the virus differs.JcDV has great potential as a biological control agent against pests such as S.frugiperda.展开更多
基金supported by the National Key Research and Development Program of China(2019YFD0300101)the Central Public-interest Scientific Institution Basal Research Fund,China(CAAS-ZDRW202007)。
文摘Fall armyworm has invaded China and colonized its populations in tropical and sub-tropical regions of South China since December 2018.Chemical spray has been widely used to control the pest,which shall lead to resistance evolution.In this research,we collected five populations of the pest from Yunnan,Hainan,Tibet,and Fujian of China,and tested their susceptibilities to pyrethroid,organophosphorus,oxadiazine,diamide,antibiotics and other types of insecticides(14 insecticides totally)in the laboratory.Based on the susceptible baseline published from the previous studies,the resistance ratio was 615-1068-fold to chlorpyrifos,60-388-fold to spinosad,26-317-fold to lambda-cyhalothrin,13-29-fold to malathion,9-33-fold to fenvalerate,8-20-fold to deltamethrin,3-8-fold to emamectin benzoate and 1-2-fold to chlorantraniliprole,respectively.The median lethal concentration(LC_(50))of other six insecticides without the susceptible baselines was 148.27-220.96μgmL^(-1) for beta-cypermethrin,87.03-128.43μgmL^(-1) for chlorfenapyr,16.35-99.67μgmL^(-1) for indoxacarb,10.55-51.01μgmL^(-1) for phoxim,7.08-8.78μgmL^(-1) for M-EBI(the mixed insecticide of emamectin benzoate and indoxcarb)and 1.49-4.64μg mL^(-1) for cyantraniliprole.This study can be helpful for chemical control as well as for resistance monitoring and management of the pest in China.
基金supported by the Key Project for Breeding Genetic Modified Organisms of China(2016ZX08012004003)。
文摘ATP-binding cassette transporter C2(ABCC2)is known to be a receptor for Bacillus thuringiensis(Bt)toxins in several lepidopteran insects.Mutations in the ABCC2 gene have been genetically linked to field-evolved resistance to the Cry1 F toxin from Bt in Spodoptera frugiperda.Here we generated a SfABCC2 knockout strain of S.frugiperda using the CRISPR/Cas9 system to provide further functional evidence of the role of this gene in susceptibility and resistance to Cry1 F.Results from bioassays showed that the SfABCC2 knockout S.frugiperda strain displayed 118-fold resistance to Cry1 F compared with the parental DH19 strain,but no resistance to Vip3 A toxin from Bt.These results provide the first reverse genetic evidence for SfABCC2 as a functional receptor for Cry1 F.
基金funded by the National Genetically Modified Organism New Variety Breeding Program of China(2019ZX08012-004)。
文摘The fall armyworm(FAW)Spodoptera frugiperda,which originated in the Americas,is advancing across China and threatening the nation’s maize crops.Currently,one widely used tool for its control is genetically modified(GM)Bacillus thuringiensis(Bt)maize.Sufficient content of Bt protein in appropriate plant parts is crucial for enhancing resistance against insect pests.In this study,we conducted a systematic investigation of Cry1 Ab levels in Chinese domestic GM maize DBN9936,which has recently obtained a biosafety certificate,and evaluated its efficacy against FAW.Quantification of expression levels of Cry1 Ab,via ELISA,indicated a spatio-temporal dynamic,with significant variation of mean Cry1 Ab,ranging from 0.76 to 8.48μg g-1 FW with the Cry1 Ab protein level ranked as:V6-V8 leaf>R1 leaf>R4 leaf>R1 silk>VT tassel>R4 kernel.Among the nine locations,the Cry1 Ab levels in DBN9936 of the Xinxiang,Langfang,and Harbin fields were significantly lower than those from Wuhan and Shenyang,and were slightly,but not significantly lower than those from the other four fields.Furthermore,the artificial diet-Cry1 Ab mixture and plant tissue feeding bioassays revealed that DBN9936 has high efficacy against FAW.The insecticidal efficacy of different tissues against FAW larvae reached 34-100%with a descending order of lethality as follows:VT leaf>R4 leaf>R1 husk>R1 silk>VT tassel>R4 kernel.Taken together,our results showed that Bt-Cry1 Ab maize DBN9936 has potential as a promising strategy to manage FAW.
文摘The fall armyworm(Spodoptera frugiperda)is a major agricultural pest native to the Americas.It is widely distributed throughout the Western Hemisphere.It damages crops such as maize,wheat,rice,sorghum,cotton,herbage and various weeds,and reportedly feeds on more than 300 species(Montezano et al.2018).Fall army wo rm is a typical lepidoptera pest and goes through four life stages:egg,larva,pupa and adult Adults can lay eggs between 1000 and 2000 and complete a life cycle within about 30 days,reproducing at a fast speed.There are two biotypes of fall armyworm:Corn-biotype(C-strain)and Rice-biotype(R-strain).
基金supported by the National Key R&D Program of China(2017YFD0200400)the Natural Science Foundation of Hubei Province,China(2017CFB241)。
文摘The fall armyworm,Spodoptera frugiperda,which destroys many economic crops such as rice and maize,has recently invaded China.Insect viruses as biological control agents play important roles in killing pests.One potential viral insecticide is the environmentally highly infective and virulent densovirus.We successfully rescued Junonia coenia densovirus(JcDV)using its infectious clone in different insect cell lines and larvae of three insect species.Results showed that the lysate of cultured insect cells transfected by the JcDV infectious clone killed the 2 nd instar S.frugiperda.The LD50 of homogenate from JcDV-infected Spodoptera litura to the 2 nd instar S.frugiperda(1.76×10^(8)viral genome copies per larva during 10 d post infection)was higher than that of the 2 nd instar S.litura(7.39×10^(7)Jc DV genome copies)or Helicoverpa armigera larvae(9.71×10^(7)JcDV genome copies).The LT50 of the S.litura homogenate(2.60×10^(9)viral genome copies each larva)to the 2 nd instar S.frugiperda was 6.96 d,longer than that of the S.litura(6.18 d)or the 2 nd instar H.armigera(5.94 d).JcDV could infect the fat body of H.armigera,but not S.frugiperda or S.litura.Although JcDV can infect all three lepidopteran species,their susceptibility to the virus differs.JcDV has great potential as a biological control agent against pests such as S.frugiperda.
