[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings wer...[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings were cultivated in the laboratory at （25±1）℃, 60-75% RH, and a photoperiod of 14：10 （L：D） h. The green blow molding papers were used to collect eggs, and Brassica oleracea seedlings were cultivated to breed Plutella xylostella L. until the insects were ready for use. Mean-while, the susceptibility of 3rd instar larvae of Plutella xylostella L. to five types of insecticides was tested by leaf-dipping method. [Result] Plutella xylostella L. larvae were found well-grown and uniform in developmental stages with average pupa weight of 5.4 mg, pupa emergence percentage of 94.0 % and egg number of 135.1 per female. The LCso values of 3rd instar Plutella xylostella L. larvae against 200 g/L chlorantraniliprole SC, 20% flubendiamide WG, 150 g/L indoxacarb EC, 200 g/L tebufenozide SC and 1.8% abamectin EC, were 0.152, 0.223, 1.151, 93.340 and 0.128 mg/L, respectively. [Conclusion] This rearing method is easy to be implemented and of great practicality, suitable for mass propagation of P. xylostella L. Abamectin, chlorantraniliprole and flubendiamide showed high insecticidal activities, so these three insecticides can be used alternately for the field prevention and control of Plutella xylostella L.展开更多
The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 valu...The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.展开更多
[Objective] The research aimed to lay a foundation for the screening of cell lines producing secondary metabolites of Brucea javanica(L.)Merr.[Method] The insecticidal activities of the extracts from branch and 3 diff...[Objective] The research aimed to lay a foundation for the screening of cell lines producing secondary metabolites of Brucea javanica(L.)Merr.[Method] The insecticidal activities of the extracts from branch and 3 different types of calluses of Brucea javanica(L.)Merr.was detected through methods of leaf disc and potted seedlings against the diamond back moth.[Result] Extracts from four kinds of Brucea javanica(L.)Merr.tissues assumed both the activities of antifeedant and oviposition deterrency against the diamond back moth.Antifeedant effect of extracts was in turn the callus C< callus B< callus A< branches.Oviposition deterrency activity of the extracts was in turn the callus A> branch > callus B>callus C.The insecticidal activities of callus A and B were higher than that of the callus C.[Conclusion] The results show that insecticidal activity of callus and its growth rate is inversely proportional.展开更多
基金Supported by Key Technologies of R&D Program of Shanxi Province(20120311019-1)Research Project Supported by Shanxi Scholarship Council of China(2012-110)+1 种基金Doctoral Research Fund of Shanxi Academy of Agricultural Sciences(YBSJJ1006)Key Technologies of R&D Program of Shanxi Academy of Agricultural Sciences(2012ygg16)~~
文摘[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings were cultivated in the laboratory at （25±1）℃, 60-75% RH, and a photoperiod of 14：10 （L：D） h. The green blow molding papers were used to collect eggs, and Brassica oleracea seedlings were cultivated to breed Plutella xylostella L. until the insects were ready for use. Mean-while, the susceptibility of 3rd instar larvae of Plutella xylostella L. to five types of insecticides was tested by leaf-dipping method. [Result] Plutella xylostella L. larvae were found well-grown and uniform in developmental stages with average pupa weight of 5.4 mg, pupa emergence percentage of 94.0 % and egg number of 135.1 per female. The LCso values of 3rd instar Plutella xylostella L. larvae against 200 g/L chlorantraniliprole SC, 20% flubendiamide WG, 150 g/L indoxacarb EC, 200 g/L tebufenozide SC and 1.8% abamectin EC, were 0.152, 0.223, 1.151, 93.340 and 0.128 mg/L, respectively. [Conclusion] This rearing method is easy to be implemented and of great practicality, suitable for mass propagation of P. xylostella L. Abamectin, chlorantraniliprole and flubendiamide showed high insecticidal activities, so these three insecticides can be used alternately for the field prevention and control of Plutella xylostella L.
基金support for this work was provided by the National Natural Science Foundation of China(30971922)the Natural Science Foundation of Fujian Province, China (B0320003, B0410015, 2004J010, and2007F5021)+1 种基金the Science and Technology Innovation Foundation of Fujian Academy of Agricultural Science,China (STIF-Y07)the Program for New Century Excellent Talents in University of Fujian Province, China,to Associate Professor Gu Xiaojun
文摘The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.
基金Supported by Guangxi Science Foundation(0639027)Science and Technology Developmental Fund of Guangxi Academy of Agricultural Sciences(2006025)~~
文摘[Objective] The research aimed to lay a foundation for the screening of cell lines producing secondary metabolites of Brucea javanica(L.)Merr.[Method] The insecticidal activities of the extracts from branch and 3 different types of calluses of Brucea javanica(L.)Merr.was detected through methods of leaf disc and potted seedlings against the diamond back moth.[Result] Extracts from four kinds of Brucea javanica(L.)Merr.tissues assumed both the activities of antifeedant and oviposition deterrency against the diamond back moth.Antifeedant effect of extracts was in turn the callus C< callus B< callus A< branches.Oviposition deterrency activity of the extracts was in turn the callus A> branch > callus B>callus C.The insecticidal activities of callus A and B were higher than that of the callus C.[Conclusion] The results show that insecticidal activity of callus and its growth rate is inversely proportional.
