The model for predicting vegetable pest diamondback moth was established based on E-Support Vector Regression algorithms in the multiply occurrence season of diamondback moth. The experimental data of diamondback moth...The model for predicting vegetable pest diamondback moth was established based on E-Support Vector Regression algorithms in the multiply occurrence season of diamondback moth. The experimental data of diamondback moth in Guangdong vegetable were analyzed, and the result showed that when penalty factor c was 43, kernel function parameter k was O. 2, the better prediction result could be obtained by the early warning model of E-Support Vector Regression algorithms.展开更多
To obtain transgenic cabbage line with broad insect resistance, a new synthetic Bacillus thuringiensis crylBa3 gene was introduced into white cabbage via Agrobacterium tumefaciens-mediated transformation and 37 transf...To obtain transgenic cabbage line with broad insect resistance, a new synthetic Bacillus thuringiensis crylBa3 gene was introduced into white cabbage via Agrobacterium tumefaciens-mediated transformation and 37 transformants were obtained. Polymerase chain reaction （PCR） and Southern blot analyses confirmed that crylBa3 was successfully inserted into the genome of cabbage. Reverse transcription-polymerase chain reaction （RT-PCR） demonstrated that crylBa3 was expressed. Western blot results confirmed the production of insecticidal protein encoded by crylBa3. Insect bioassays showed that transgenic cabbages effectively controlled both susceptible and CrylAc-resistant diamondback moth （DBM） larvae.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
Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to lar...Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension. The application of aqueous suspensions of cells of X.nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests on foliage.展开更多
A new artificial diet for the diamondback moth,Plutella Xylostella(L), had been selected out successfully. The diet contained the following constituents: soybean powder, wheat germ, wheat bran powder, brewer's ye...A new artificial diet for the diamondback moth,Plutella Xylostella(L), had been selected out successfully. The diet contained the following constituents: soybean powder, wheat germ, wheat bran powder, brewer's yeast and other constituents. So far, the diamondback; moth had been reared on this artificial diet for 25 generations and still mantained its normal biological characteristics. Under 25±1℃ and 60%￣75%RH with 12 h PH,the results of rearing the diamondback moth on the diet as follows:egg hatch,81. 3%￣94. 7 %; survival from eggsto pupae, 55. 0% ￣ 76. 7 % 1 pupal survival, 79. 7 % ￣ 100 % ; adult emergence, 80% ￣ 100 %; fecundity 94. 7￣ 144.4 eggs/ ;pupal weight, 90. 4￣110. 8 mg/20 pupae; average days to adult: , 10. 2; 13. 1. The diet is not only simpler on the constituents but also have better r-earing results and more rearing generations.展开更多
C-type lectins(CTLs)are a superfamily of Ca^(2+)-dependent carbohydrate-recognition proteins,and an important pattern recognition receptor(PRR)in insect innate immunity which can mediate humoral and cellular immunity ...C-type lectins(CTLs)are a superfamily of Ca^(2+)-dependent carbohydrate-recognition proteins,and an important pattern recognition receptor(PRR)in insect innate immunity which can mediate humoral and cellular immunity in insects.In this study,we report a novel dual carbohydrate-recognition domain(CRD)CTL from Plutella xylostella which we designate PxIML.PxIML is a protein with a 969 bp open reading frame(ORF)encoding 322 amino acids,containing a signal peptide and a dual-CRD with EPN(Glu_(124)-Pro_(125)-Asn_(126))and QPD(Gln_(274)-Pro_(275)-Asp_(276))motifs.The expression of PxIML mRNA in the fat body was significantly higher than in hemocytes and midgut.The relative expression levels of PxIML in the whole insect and the fat body were significantly inhibited after infection with Bacillus thuringiensis 8010(Bt8010)at 18 h,while they were significantly upregulated after infection with Serratia marcescens IAE6 or Pichia pastoris.The recombinant PxIML(rPxIML)protein could bind to the tested pathogen-associated molecular patterns(PAMPs),and the bacteria of Enterobacter sp.IAE5,S.marcescens IAE6,Staphylococcus aureus,Escherichia coli BL21,and Bt8010 in a Ca^(2+)-dependent manner,however,it showed limited binding to the fungus,P.pastoris.The rPxIML exhibited strong activity in the presence of Ca^(2+) to agglutinate Bt8010,Enterobacter sp.IAE5 and S.aureus,but it only weakly agglutinated with E.coli BL21,and could not agglutinate with S.marcescens IAE6 or P.pastoris.Furthermore,the rPxIML could bind to hemocytes,promote the adsorption of hemocytes to beads,and enhance the phenoloxidase(PO)activity and melanization of P.xylostella.Our results suggest that PxIML plays an important role in pathogen recognition and in mediating subsequent humoral and cellular immunity of P.xylostella.展开更多
Resistance of diamondback moth （ Plutella xylostella L. ） population against eight kinds of insecticides in Luliang County of Yunnan Province in China was determined in laboratory by leaf dipping method in autumn of...Resistance of diamondback moth （ Plutella xylostella L. ） population against eight kinds of insecticides in Luliang County of Yunnan Province in China was determined in laboratory by leaf dipping method in autumn of 2009 and spring of 2010. The monitoring results showed that diamondback moth population in Lu- liang County of Yunnan Province had produced extremely high resistance against beta-cypermethrin and avermectin; LC50 in autumn of 2009 were 1 035.21 and 1 055.19 mg/L, while those in spring of 2010 were 9.55 and 13.84 mg/L, respectively; the resistance ratios were from 291.61 to 692.00. The diamondback moth population had moderately high resistance to spinosad, indoxacarb and chlorfluazuron; LC50, in autumn of 2009 were 1.59, 2.80 and 23.97 mg/L, while those in spring of 2010 were 13.83,24.57 and 42.73 mg/L, respectively; the resistance ratios were froml3.25 to 129.98. The diamondback moth population was sensitive to diafenthiuron, BT and chlorfenapyr; LC50 in autumn of 2009 were 16.51, 47.40 and 0.85 mg/L, while those in spring of 2010 were 1.34, 3.38 and 1.60 mg/L, respectively; the resistance ratios were from 0. 77 to 8.45. The resistance of diamondback moth population in Luliang County of Yunnan Province against eight kinds of insecticides successively were diafenthiuron 〈 BT preparations 〈 chlorfenapyr 〈 spinosad 〈 indoxacarb 〈 chlorfluazuron 〈 beta-cypermethrin 〈 ave rmectin, and the resistance in spring was higher than that in autumn.展开更多
The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with l...The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with low-risk insecticides. The aim of this study was to select an insecticide or insecticide mixture that could be adopted by small-scale growers for diamondback moth management. The effectiveness of four insecticide mixtures, i.e., Agroneem Plus （neem-derived）, Spinosad （microbial origin）, thiamethoxam （neonicotinoid） and a homemade methanol Jalapefio pepper extract, in laboratory bioassays was evaluated. Binary mixtures were tested against single products at manufacturer＇s label rates. These were applied to collard greens using the leaf dip method and fed to the newly molted 2nd or 3rd instar larvae. Mixtures were evaluated for efficacy based on larval mortality and consumption of leaf discs. The results showed interactions between Jalapefio pepper extract and Spinosad and between the neem-derived Agroneem Plus and thiamethoxam at some of the tested concentrations. Mixtures with at any amount of Spinosad killed all larvae. The neem-based product gave inconsistent results in some treatments; in some case, increased leaf damage did not result in commensurate larval mortalities. The reported resistance of diamondback moth larvae to Spinosad was not observed during this study, neither with Spinosad alone nor in mixtures.展开更多
The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae...The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae parasitism in the adj acent plots. It reached to 42.96% in treatment plot and 18.19% in the control. Although there was no significant difference in no. of diamondback moth （DBM） larvae per plant, 29.09% in population reduction was occurred in treatment plot. Abundance of cabbage looper and armyworm were also lower in adjacent plot. But, small white butterfly population （23.46%） was higher in adjacent plots as the result of Dendranthema plant. From the present experiment, Dendranthema flowering plants should be cultivated in Brasssicaceous crops for the control of DBM by providing the essential resources to larval parasitoid C. plutellae adults and then, this plant can be used as attractive plant in the control of small white butterfly. Serious elimination （Rating 4） of candidate insecticides to adult C. plutellae was observed at their recommendation doses. Among them, less toxic effect to C. plutellae was occurred in O,O-dimethyl S-methylcarbamoylmethyl which is the highest LC50 （4,765 ppm） to DBM by leaf-disc bioassay method and the lowest LC50 （2,903 pprn） was found in marlathion. It was occurred that the test strain have resistance to the recommended dose of marlathion （1,243 ppm） and O,O-dimethyl S-methylcarbamoylmethyl （3,750 ppm）.展开更多
Effects of hexaflumuron at 10% lethal concentration （LC10） and LC25 on development and reproduction parameters of the diamondback moth, Plutella xylostella （Linnaeus, 1753） （Lep.： Yponomeutidae） were investigat...Effects of hexaflumuron at 10% lethal concentration （LC10） and LC25 on development and reproduction parameters of the diamondback moth, Plutella xylostella （Linnaeus, 1753） （Lep.： Yponomeutidae） were investigated. Estimated LC50, LC10 and LC25 values of leaf dip bioassay of hexaflumuron on the third instar larvae of the P xylostella were 1.48, 0.59 and 0.91 mg/L, respectively. Hexaflumuron decreased pupal weight in the parent generation at sublethal concentrations but in the offspring generation, this effect was not observed. Sublethal concentrations increased egg, first and second larval instar and pupa developmental time and shortened life span of adults, but did not change the third and fourth larval instars and pre-pupa developmental period. Also fecundity of females reduced significantly but hatchability of treatments and control were similar. Survival rate of pre-adult stages declined significantly at LC25 concentration. Reproduction parameters such as reproductive rate （R0） and intrinsic rate of increase in sublethal concentrations were significantly lower compared with control, but gross reproduction rate （GRR） at the LC10 concentration was increased and it could be hormoligosis. Also hexaflumuron significantly increased doubling time （Dt）. We conclude that the sublethal effects of hexaflumuron might exhibit significant effects on the population dynamics of P xylostella.展开更多
The volatiles, absorbed by Porapak Q and eluted by hexane, from Chinese cabbage, Brassica campestris chinesis (L.) Makino. van communis Tsen et Lee, have been identified as allyl isothiocyanate, Z-3-hexenyl acetate, 3...The volatiles, absorbed by Porapak Q and eluted by hexane, from Chinese cabbage, Brassica campestris chinesis (L.) Makino. van communis Tsen et Lee, have been identified as allyl isothiocyanate, Z-3-hexenyl acetate, 3,7-dimethyl-l,3,6-octatriene, 2,5-hexanediol, Z-3-hexen-l-ol, nonanol, β-myrcene, α-pinene, E-2-hexen-l-ol, D-limonene, Z-3-hexenyl propanoate, linalool, geraniol, E-4-hexen-l-ol, Z-3-hexenyl isovalerate, α-terpinene, β-caryophyllene, 3-carene and α-caryophyllene, by their mass spectra and retention times in comparison with authentic samples. The first five chemicals are the main components. All components can elicite electroantennogram (EAG) responses of dia-mondback moth (DBM), Plutella xylostella, in which allyl isothiocyanate and C6 alcohols and esters, i.e. Z-3-hexen-l-ol, E-2-hexen-l-ol, E-4-hexen-l-ol, Z-3-hexenyl isovalerate and 2,5-hexanediol elicite stronger EAG responses than other components, and EAG responses of female moths to them are slightly larger than those of male展开更多
Populations of Australian diamondback moth （DBM） Plutella xylostella （L.）, a serious pest of cruciferous crops, display extremely low levels of genetic differentiation across Australia and New Zealand sample locat...Populations of Australian diamondback moth （DBM） Plutella xylostella （L.）, a serious pest of cruciferous crops, display extremely low levels of genetic differentiation across Australia and New Zealand sample locations, as determined previously using microsatellite markers. These data suggest high levels of contemporary gene flow that is consistent with Australian DBM being a vagile species. Here we examine Australian DBM samples for haplotype variation using the mitochondrial DNA sequences of a 257 bp fragment of the CO1 gene. We compare this variation to equivalent mtDNA sequence variation in samples from New Zealand, Kenya and Korea. Using 42 moths collected throughout Australia we show that Australian DBM have both low mtDNA haplotype and nucleotide diversities. The three Australian haplotypes detected are closely related and they cluster with the common haplotype group from Indonesia. In addition the Australian haplotype frequency distribution resembled more that from Indonesia than that from Kenya or Korea. These data are consistent with an original strong Australian/New Zealand founder effect, from a south-eastern Asian source, with subsequent continued isolation. In a single season, the frequency of PXMt01, the most common Australian haplotype, was estimated at 15 locations spread across southern Australia and New Zealand using a polymerase chain reaction BiPASA method. The PXMt01 haplotype frequency variation was heterogenous, suggesting a small degree of population isolation that was not detected using microsatellites. Differentiation was not a function of geographical distance. These data suggest transient and sporadic local colonisation events by small numbers of founding females.展开更多
The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it ...The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it increasingly dificult to control.Genetics-based control approaches,through manipulation of target genes,have been reported as promising supplements or alternatives to traditional methods of pest management.Here we identified a gene of pigmentation(yellow)in P.xylostella,Pxyellow,which encodes 1674 bp complementary DNA sequence with four exons and three introns.Using the clustered regularly interspersed palindromic repeats(CRISPR)CRISPR-associated protein 9 system,we knocked out Pxyellow,targeting two sites in Exon III,to generate 272 chimeric mutants(57%of the CRISPR-treated individuals)with color-changed phenotypes of the Ist to 3rd instar larvae,pupae,and adults,indicating that Pxyellow plays an essential role in the body pigmentation of P xlostella.Fitness analysis revealed no significant difference in the oviposition of adults,the hatchability of eggs,and the weight of pupac between homozygous mutants and wildtypes,suggesting that Pxyellow is not directly involved in regulation of growth,development,or reproduction.This work advances our understanding of the genetic and insect science molecular basis for body pigmentation of P xylostella,and opens a wide avenue for development of the genctcally based pest control techniques using Pxyellow as a screening marker.展开更多
基金Supported by Science and Technology Projects in Guangdong Province(2009CD058,2009CD078,2009CD079,2009CD080)~~
文摘The model for predicting vegetable pest diamondback moth was established based on E-Support Vector Regression algorithms in the multiply occurrence season of diamondback moth. The experimental data of diamondback moth in Guangdong vegetable were analyzed, and the result showed that when penalty factor c was 43, kernel function parameter k was O. 2, the better prediction result could be obtained by the early warning model of E-Support Vector Regression algorithms.
基金supported by the grants from the National High Technology Researchand Development Program of China (863 Program,2008AA10Z155)the National Natural Science Foundation of China (31071697)the earmarked fund for the Modern Agro-Industry Technology Research System,China (nycytx-35-gw01)
文摘To obtain transgenic cabbage line with broad insect resistance, a new synthetic Bacillus thuringiensis crylBa3 gene was introduced into white cabbage via Agrobacterium tumefaciens-mediated transformation and 37 transformants were obtained. Polymerase chain reaction （PCR） and Southern blot analyses confirmed that crylBa3 was successfully inserted into the genome of cabbage. Reverse transcription-polymerase chain reaction （RT-PCR） demonstrated that crylBa3 was expressed. Western blot results confirmed the production of insecticidal protein encoded by crylBa3. Insect bioassays showed that transgenic cabbages effectively controlled both susceptible and CrylAc-resistant diamondback moth （DBM） larvae.
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.
文摘Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension. The application of aqueous suspensions of cells of X.nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests on foliage.
文摘A new artificial diet for the diamondback moth,Plutella Xylostella(L), had been selected out successfully. The diet contained the following constituents: soybean powder, wheat germ, wheat bran powder, brewer's yeast and other constituents. So far, the diamondback; moth had been reared on this artificial diet for 25 generations and still mantained its normal biological characteristics. Under 25±1℃ and 60%￣75%RH with 12 h PH,the results of rearing the diamondback moth on the diet as follows:egg hatch,81. 3%￣94. 7 %; survival from eggsto pupae, 55. 0% ￣ 76. 7 % 1 pupal survival, 79. 7 % ￣ 100 % ; adult emergence, 80% ￣ 100 %; fecundity 94. 7￣ 144.4 eggs/ ;pupal weight, 90. 4￣110. 8 mg/20 pupae; average days to adult: , 10. 2; 13. 1. The diet is not only simpler on the constituents but also have better r-earing results and more rearing generations.
基金the project of the National Key R&D Program of China(2017YFE0122000)the National Natural Science Foundation of China(31871968)the Natural Science Foundation of Fujian Province,China(2018J01614).
文摘C-type lectins(CTLs)are a superfamily of Ca^(2+)-dependent carbohydrate-recognition proteins,and an important pattern recognition receptor(PRR)in insect innate immunity which can mediate humoral and cellular immunity in insects.In this study,we report a novel dual carbohydrate-recognition domain(CRD)CTL from Plutella xylostella which we designate PxIML.PxIML is a protein with a 969 bp open reading frame(ORF)encoding 322 amino acids,containing a signal peptide and a dual-CRD with EPN(Glu_(124)-Pro_(125)-Asn_(126))and QPD(Gln_(274)-Pro_(275)-Asp_(276))motifs.The expression of PxIML mRNA in the fat body was significantly higher than in hemocytes and midgut.The relative expression levels of PxIML in the whole insect and the fat body were significantly inhibited after infection with Bacillus thuringiensis 8010(Bt8010)at 18 h,while they were significantly upregulated after infection with Serratia marcescens IAE6 or Pichia pastoris.The recombinant PxIML(rPxIML)protein could bind to the tested pathogen-associated molecular patterns(PAMPs),and the bacteria of Enterobacter sp.IAE5,S.marcescens IAE6,Staphylococcus aureus,Escherichia coli BL21,and Bt8010 in a Ca^(2+)-dependent manner,however,it showed limited binding to the fungus,P.pastoris.The rPxIML exhibited strong activity in the presence of Ca^(2+) to agglutinate Bt8010,Enterobacter sp.IAE5 and S.aureus,but it only weakly agglutinated with E.coli BL21,and could not agglutinate with S.marcescens IAE6 or P.pastoris.Furthermore,the rPxIML could bind to hemocytes,promote the adsorption of hemocytes to beads,and enhance the phenoloxidase(PO)activity and melanization of P.xylostella.Our results suggest that PxIML plays an important role in pathogen recognition and in mediating subsequent humoral and cellular immunity of P.xylostella.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest"Research and Demonstration of Sustainable Prevention and Control Technology against Diamondback Moth"(200803001)"Research and Demonstration of Integrated Prevention and Control Technology against Diamondback Moth in Cruciferous Vegetables"(201103021)
文摘Resistance of diamondback moth （ Plutella xylostella L. ） population against eight kinds of insecticides in Luliang County of Yunnan Province in China was determined in laboratory by leaf dipping method in autumn of 2009 and spring of 2010. The monitoring results showed that diamondback moth population in Lu- liang County of Yunnan Province had produced extremely high resistance against beta-cypermethrin and avermectin; LC50 in autumn of 2009 were 1 035.21 and 1 055.19 mg/L, while those in spring of 2010 were 9.55 and 13.84 mg/L, respectively; the resistance ratios were from 291.61 to 692.00. The diamondback moth population had moderately high resistance to spinosad, indoxacarb and chlorfluazuron; LC50, in autumn of 2009 were 1.59, 2.80 and 23.97 mg/L, while those in spring of 2010 were 13.83,24.57 and 42.73 mg/L, respectively; the resistance ratios were froml3.25 to 129.98. The diamondback moth population was sensitive to diafenthiuron, BT and chlorfenapyr; LC50 in autumn of 2009 were 16.51, 47.40 and 0.85 mg/L, while those in spring of 2010 were 1.34, 3.38 and 1.60 mg/L, respectively; the resistance ratios were from 0. 77 to 8.45. The resistance of diamondback moth population in Luliang County of Yunnan Province against eight kinds of insecticides successively were diafenthiuron 〈 BT preparations 〈 chlorfenapyr 〈 spinosad 〈 indoxacarb 〈 chlorfluazuron 〈 beta-cypermethrin 〈 ave rmectin, and the resistance in spring was higher than that in autumn.
文摘The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with low-risk insecticides. The aim of this study was to select an insecticide or insecticide mixture that could be adopted by small-scale growers for diamondback moth management. The effectiveness of four insecticide mixtures, i.e., Agroneem Plus （neem-derived）, Spinosad （microbial origin）, thiamethoxam （neonicotinoid） and a homemade methanol Jalapefio pepper extract, in laboratory bioassays was evaluated. Binary mixtures were tested against single products at manufacturer＇s label rates. These were applied to collard greens using the leaf dip method and fed to the newly molted 2nd or 3rd instar larvae. Mixtures were evaluated for efficacy based on larval mortality and consumption of leaf discs. The results showed interactions between Jalapefio pepper extract and Spinosad and between the neem-derived Agroneem Plus and thiamethoxam at some of the tested concentrations. Mixtures with at any amount of Spinosad killed all larvae. The neem-based product gave inconsistent results in some treatments; in some case, increased leaf damage did not result in commensurate larval mortalities. The reported resistance of diamondback moth larvae to Spinosad was not observed during this study, neither with Spinosad alone nor in mixtures.
文摘The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae parasitism in the adj acent plots. It reached to 42.96% in treatment plot and 18.19% in the control. Although there was no significant difference in no. of diamondback moth （DBM） larvae per plant, 29.09% in population reduction was occurred in treatment plot. Abundance of cabbage looper and armyworm were also lower in adjacent plot. But, small white butterfly population （23.46%） was higher in adjacent plots as the result of Dendranthema plant. From the present experiment, Dendranthema flowering plants should be cultivated in Brasssicaceous crops for the control of DBM by providing the essential resources to larval parasitoid C. plutellae adults and then, this plant can be used as attractive plant in the control of small white butterfly. Serious elimination （Rating 4） of candidate insecticides to adult C. plutellae was observed at their recommendation doses. Among them, less toxic effect to C. plutellae was occurred in O,O-dimethyl S-methylcarbamoylmethyl which is the highest LC50 （4,765 ppm） to DBM by leaf-disc bioassay method and the lowest LC50 （2,903 pprn） was found in marlathion. It was occurred that the test strain have resistance to the recommended dose of marlathion （1,243 ppm） and O,O-dimethyl S-methylcarbamoylmethyl （3,750 ppm）.
文摘Effects of hexaflumuron at 10% lethal concentration （LC10） and LC25 on development and reproduction parameters of the diamondback moth, Plutella xylostella （Linnaeus, 1753） （Lep.： Yponomeutidae） were investigated. Estimated LC50, LC10 and LC25 values of leaf dip bioassay of hexaflumuron on the third instar larvae of the P xylostella were 1.48, 0.59 and 0.91 mg/L, respectively. Hexaflumuron decreased pupal weight in the parent generation at sublethal concentrations but in the offspring generation, this effect was not observed. Sublethal concentrations increased egg, first and second larval instar and pupa developmental time and shortened life span of adults, but did not change the third and fourth larval instars and pre-pupa developmental period. Also fecundity of females reduced significantly but hatchability of treatments and control were similar. Survival rate of pre-adult stages declined significantly at LC25 concentration. Reproduction parameters such as reproductive rate （R0） and intrinsic rate of increase in sublethal concentrations were significantly lower compared with control, but gross reproduction rate （GRR） at the LC10 concentration was increased and it could be hormoligosis. Also hexaflumuron significantly increased doubling time （Dt）. We conclude that the sublethal effects of hexaflumuron might exhibit significant effects on the population dynamics of P xylostella.
基金This work was supported by the Post Doctor Science Foundation of China (Grant No. [2000]31) the National Key Basic Research and Development Program (Grant No. G20000162).
文摘The volatiles, absorbed by Porapak Q and eluted by hexane, from Chinese cabbage, Brassica campestris chinesis (L.) Makino. van communis Tsen et Lee, have been identified as allyl isothiocyanate, Z-3-hexenyl acetate, 3,7-dimethyl-l,3,6-octatriene, 2,5-hexanediol, Z-3-hexen-l-ol, nonanol, β-myrcene, α-pinene, E-2-hexen-l-ol, D-limonene, Z-3-hexenyl propanoate, linalool, geraniol, E-4-hexen-l-ol, Z-3-hexenyl isovalerate, α-terpinene, β-caryophyllene, 3-carene and α-caryophyllene, by their mass spectra and retention times in comparison with authentic samples. The first five chemicals are the main components. All components can elicite electroantennogram (EAG) responses of dia-mondback moth (DBM), Plutella xylostella, in which allyl isothiocyanate and C6 alcohols and esters, i.e. Z-3-hexen-l-ol, E-2-hexen-l-ol, E-4-hexen-l-ol, Z-3-hexenyl isovalerate and 2,5-hexanediol elicite stronger EAG responses than other components, and EAG responses of female moths to them are slightly larger than those of male
文摘Populations of Australian diamondback moth （DBM） Plutella xylostella （L.）, a serious pest of cruciferous crops, display extremely low levels of genetic differentiation across Australia and New Zealand sample locations, as determined previously using microsatellite markers. These data suggest high levels of contemporary gene flow that is consistent with Australian DBM being a vagile species. Here we examine Australian DBM samples for haplotype variation using the mitochondrial DNA sequences of a 257 bp fragment of the CO1 gene. We compare this variation to equivalent mtDNA sequence variation in samples from New Zealand, Kenya and Korea. Using 42 moths collected throughout Australia we show that Australian DBM have both low mtDNA haplotype and nucleotide diversities. The three Australian haplotypes detected are closely related and they cluster with the common haplotype group from Indonesia. In addition the Australian haplotype frequency distribution resembled more that from Indonesia than that from Kenya or Korea. These data are consistent with an original strong Australian/New Zealand founder effect, from a south-eastern Asian source, with subsequent continued isolation. In a single season, the frequency of PXMt01, the most common Australian haplotype, was estimated at 15 locations spread across southern Australia and New Zealand using a polymerase chain reaction BiPASA method. The PXMt01 haplotype frequency variation was heterogenous, suggesting a small degree of population isolation that was not detected using microsatellites. Differentiation was not a function of geographical distance. These data suggest transient and sporadic local colonisation events by small numbers of founding females.
基金the National Natural Science Foundation of China(31972271)the Strait Postdoctoral Exchange Program of Fujian(2018B002)Fujian Science and Technology Major Program(2018NZ01010013).
文摘The diamondback moth,Plutella xylostella(L.),is an economically important pest of cruciferous crops worldwide.This pest is notorious for rapid evolution of the resistance to diferent classes of insecticides,making it increasingly dificult to control.Genetics-based control approaches,through manipulation of target genes,have been reported as promising supplements or alternatives to traditional methods of pest management.Here we identified a gene of pigmentation(yellow)in P.xylostella,Pxyellow,which encodes 1674 bp complementary DNA sequence with four exons and three introns.Using the clustered regularly interspersed palindromic repeats(CRISPR)CRISPR-associated protein 9 system,we knocked out Pxyellow,targeting two sites in Exon III,to generate 272 chimeric mutants(57%of the CRISPR-treated individuals)with color-changed phenotypes of the Ist to 3rd instar larvae,pupae,and adults,indicating that Pxyellow plays an essential role in the body pigmentation of P xlostella.Fitness analysis revealed no significant difference in the oviposition of adults,the hatchability of eggs,and the weight of pupac between homozygous mutants and wildtypes,suggesting that Pxyellow is not directly involved in regulation of growth,development,or reproduction.This work advances our understanding of the genetic and insect science molecular basis for body pigmentation of P xylostella,and opens a wide avenue for development of the genctcally based pest control techniques using Pxyellow as a screening marker.
