Chemical insecticides targeting the digestive system of diamondback moth(DBM),Plutella xylostella,have not been developed.The discovery of an insecticide with novel mode of action is a challenge for the control of DBM...Chemical insecticides targeting the digestive system of diamondback moth(DBM),Plutella xylostella,have not been developed.The discovery of an insecticide with novel mode of action is a challenge for the control of DBM.In this study,a class of selenium-and difluoromethyl-modified azoles(fluoroazole selenoureas,FASU)were designed and synthesized for the control of DBM.Of these azoles,compound B4 showed the highest insecticidal activity against DBM.The LC50of third-and second-instar larvae reached 32.3 and 4.6μg mL^(–1),respectively.The midgut tissue of larvae was severely disrupted,and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4.Compound B4 led to disintegration of the peritrophic matrix,swelling of the midgut epithelium,fracture of the microvilli,and extensive leakage of cellular debris in the midgut lumen.Surviving larvae grew very slowly,and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses(LC10,LC25and LC50).Furthermore,the pupation rate,emergence rate and pupae weight were significantly decreased.Compound B4 also induced abnormal pupae,causing adults to be trapped in the cocoon or failure to fly due to twisted wings.These results demonstrated that FASU could reduce the population of DBM in sublethal doses.FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM,and its mode of action totally differs from that of commercial chemical insecticides.展开更多
The identification of functional midgut receptors for pesticidal proteins produced by Bacillus thuringiensis(Bt)is critical for deciphering the molecular mechanism of Bt resistance in insects.Reduced expression of the...The identification of functional midgut receptors for pesticidal proteins produced by Bacillus thuringiensis(Bt)is critical for deciphering the molecular mechanism of Bt resistance in insects.Reduced expression of the PxABCB1 gene was previously found to be associated with Cry1Ac resistance in the diamondback moth,Plutella xylostella(L.).To directly validate the potential receptor role of PxABCB1 and its contribution to Bt Cry1Ac toxicity in P.xylostella,we used CRISPR/Cas9 to generate a homozygous knockout ABCB1KO strain with a 5-bp deletion in exon 3 of its gene.The ABCB1KO strain exhibited a 63-fold resistance to Cry1Ac toxin compared to the parental DBM1Ac-S strain.Intriguingly,the ABCB1KO strain also exhibited significant increases in susceptibility to abamectin and emamectin benzoate.No changes in susceptibility to various other Bt Cry proteins or synthetic insecticides were observed.The knockout strain exhibited no significant fitness costs.Overall,our study indicates that PxABCB1 can protect the insect against avermectin insecticides on one hand,while on the other hand it facilitates the toxic effect of the Bt Cry1Ac toxin.The results of this study will help to inform integrated pest management approaches against this destructive pest.展开更多
[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrat...[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrated assessment of trapping efficiency of colored sticky cards and sex pheromone on Liriomyza spp.and Plutella xylostella was conducted by field surveys and structured interview in Tonghai County,Yunnan Province,China.[Result] The results showed that yellow sticky cards and sex pheromone have strong power of trapping Liriomyza spp.and Plutella xylostella（3 414±720 and（219±157） head/piece,respectively）;the control cost by the usage of pesticide is the highest,（10 099.5±2 752.5） yuan/hm^2,yellow sticky cards and sex pheromone takes the second place,（1 125.0±465.0） yuan/hm^2,the control cost by the usage of yellow sticky cards is the lowest,（450.0 ±186.0）yuan/hm^2.Without the usage of yellow sticky cards and sex pheromone,pesticide application times and costs are（15.0±2.7） times and（12 070.5±2 136.0） yuan/hm^2;combined with usage of yellow sticky cards and sex pheromone,pesticide application times and costs reduce by 5.7 times and 4 618.5 yuan/hm^2.The ratio of trapped beneficial insects and target pests was 1 ∶1 131,which showed that the negative effect of yellow sticky cards and sex pheromone on the non-target insects was very limited.[Conclusion] The trapping approach has become popular among all the local farmers.Looking at the above factors,the trapping technology has strong application prospect and promotion value in pest control field.展开更多
The resistance of field populations of Plutella xylostella, from the three vegetable producing areas （Nianyuxu Town of Yueyang City, Canggang Town of Changde City and Shatou Town of Yiyang City） in northern Hunan, t...The resistance of field populations of Plutella xylostella, from the three vegetable producing areas （Nianyuxu Town of Yueyang City, Canggang Town of Changde City and Shatou Town of Yiyang City） in northern Hunan, to seven insecticides was determined using leaf dipping method in door. The results showed that Plutella xylostella showed an extremely high-level resistance to beta-cypermethrin （resistance ratio, RR=257.13）, a high-level resistance to abamectin （RR=135.15） and indoxacarb （RR=103.08） and a moderate-level resistance to chlorfenapyr and emamectin benzoate. But Plutella xylostella is relatively sensitive to chlorantraniliprole and Bacillus thuringiensis （Bt）. Therefore, the prevention of Plutella xylostella in northern Hunan should focus on the alternative use of chlorfenapyr, emamectin benzoate, chlorantraniliprole and Bacillus thuringiensis and avoid the use of beta-cypermethrin so as to delay the generation and development of resistance to insecticides in Plutella xylostella.展开更多
为探究银杏外种皮提取物(GBEE)对小菜蛾(Plutella xylostella)的毒杀作用,本文测定了不同溶剂GBEE对3龄小菜蛾幼虫的胃毒活性和拒食活性,及其对小菜蛾幼虫3种解毒酶活性的影响。研究结果表明,3种溶剂提取GBEE对小菜蛾幼虫均有一定毒杀作...为探究银杏外种皮提取物(GBEE)对小菜蛾(Plutella xylostella)的毒杀作用,本文测定了不同溶剂GBEE对3龄小菜蛾幼虫的胃毒活性和拒食活性,及其对小菜蛾幼虫3种解毒酶活性的影响。研究结果表明,3种溶剂提取GBEE对小菜蛾幼虫均有一定毒杀作用,其中甲醇银杏外种皮提取物对小菜蛾的24 h LC_(50)为216.884 mg/mL,48 h LC_(50)为48.781 mg/mL;12 h AFC_(50)为230.083 mg/mL,24 h AFC_(50)57.560 mg/mL。LC_(50)剂量下处理小菜蛾后,CarE、GSTs和MFO活性引导24 h降低,表现为抑制作用,之后活性诱导升高,表现为激活作用。综上所述,银杏外种皮提取物对小菜蛾具有一定的毒杀作用,主要作用方式为胃毒作用和拒食作用,CarE、GSTs和MFO 3种解毒酶活性表现为先降低后升高。展开更多
基金financially supported by funding from the Guangdong Basic and Applied Basic Research Foundation,China(2019B151502052)the Program of Science and Technology of Guangzhou,China(202002030295)。
文摘Chemical insecticides targeting the digestive system of diamondback moth(DBM),Plutella xylostella,have not been developed.The discovery of an insecticide with novel mode of action is a challenge for the control of DBM.In this study,a class of selenium-and difluoromethyl-modified azoles(fluoroazole selenoureas,FASU)were designed and synthesized for the control of DBM.Of these azoles,compound B4 showed the highest insecticidal activity against DBM.The LC50of third-and second-instar larvae reached 32.3 and 4.6μg mL^(–1),respectively.The midgut tissue of larvae was severely disrupted,and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4.Compound B4 led to disintegration of the peritrophic matrix,swelling of the midgut epithelium,fracture of the microvilli,and extensive leakage of cellular debris in the midgut lumen.Surviving larvae grew very slowly,and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses(LC10,LC25and LC50).Furthermore,the pupation rate,emergence rate and pupae weight were significantly decreased.Compound B4 also induced abnormal pupae,causing adults to be trapped in the cocoon or failure to fly due to twisted wings.These results demonstrated that FASU could reduce the population of DBM in sublethal doses.FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM,and its mode of action totally differs from that of commercial chemical insecticides.
基金the Laboratory of Lingnan Modern Agriculture Project,China(NT2021003)National Natural Science Foundation of China(32022074,32221004 and 32172458)Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables,Chinese Academy of Agricultural Sciences,and the Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-CSCB-202303)。
文摘The identification of functional midgut receptors for pesticidal proteins produced by Bacillus thuringiensis(Bt)is critical for deciphering the molecular mechanism of Bt resistance in insects.Reduced expression of the PxABCB1 gene was previously found to be associated with Cry1Ac resistance in the diamondback moth,Plutella xylostella(L.).To directly validate the potential receptor role of PxABCB1 and its contribution to Bt Cry1Ac toxicity in P.xylostella,we used CRISPR/Cas9 to generate a homozygous knockout ABCB1KO strain with a 5-bp deletion in exon 3 of its gene.The ABCB1KO strain exhibited a 63-fold resistance to Cry1Ac toxin compared to the parental DBM1Ac-S strain.Intriguingly,the ABCB1KO strain also exhibited significant increases in susceptibility to abamectin and emamectin benzoate.No changes in susceptibility to various other Bt Cry proteins or synthetic insecticides were observed.The knockout strain exhibited no significant fitness costs.Overall,our study indicates that PxABCB1 can protect the insect against avermectin insecticides on one hand,while on the other hand it facilitates the toxic effect of the Bt Cry1Ac toxin.The results of this study will help to inform integrated pest management approaches against this destructive pest.
基金Supported by Development Program of Misereor Foundation of Germany(335-0311028Z)~~
文摘[Objective] To evaluate the control effect of yellow sticky cards and sex pheromone on Plutella xylostella and Liriomyza spp.,which can provide reference for large area extension of the technique.[Method] The integrated assessment of trapping efficiency of colored sticky cards and sex pheromone on Liriomyza spp.and Plutella xylostella was conducted by field surveys and structured interview in Tonghai County,Yunnan Province,China.[Result] The results showed that yellow sticky cards and sex pheromone have strong power of trapping Liriomyza spp.and Plutella xylostella（3 414±720 and（219±157） head/piece,respectively）;the control cost by the usage of pesticide is the highest,（10 099.5±2 752.5） yuan/hm^2,yellow sticky cards and sex pheromone takes the second place,（1 125.0±465.0） yuan/hm^2,the control cost by the usage of yellow sticky cards is the lowest,（450.0 ±186.0）yuan/hm^2.Without the usage of yellow sticky cards and sex pheromone,pesticide application times and costs are（15.0±2.7） times and（12 070.5±2 136.0） yuan/hm^2;combined with usage of yellow sticky cards and sex pheromone,pesticide application times and costs reduce by 5.7 times and 4 618.5 yuan/hm^2.The ratio of trapped beneficial insects and target pests was 1 ∶1 131,which showed that the negative effect of yellow sticky cards and sex pheromone on the non-target insects was very limited.[Conclusion] The trapping approach has become popular among all the local farmers.Looking at the above factors,the trapping technology has strong application prospect and promotion value in pest control field.
文摘The resistance of field populations of Plutella xylostella, from the three vegetable producing areas （Nianyuxu Town of Yueyang City, Canggang Town of Changde City and Shatou Town of Yiyang City） in northern Hunan, to seven insecticides was determined using leaf dipping method in door. The results showed that Plutella xylostella showed an extremely high-level resistance to beta-cypermethrin （resistance ratio, RR=257.13）, a high-level resistance to abamectin （RR=135.15） and indoxacarb （RR=103.08） and a moderate-level resistance to chlorfenapyr and emamectin benzoate. But Plutella xylostella is relatively sensitive to chlorantraniliprole and Bacillus thuringiensis （Bt）. Therefore, the prevention of Plutella xylostella in northern Hunan should focus on the alternative use of chlorfenapyr, emamectin benzoate, chlorantraniliprole and Bacillus thuringiensis and avoid the use of beta-cypermethrin so as to delay the generation and development of resistance to insecticides in Plutella xylostella.
文摘为探究银杏外种皮提取物(GBEE)对小菜蛾(Plutella xylostella)的毒杀作用,本文测定了不同溶剂GBEE对3龄小菜蛾幼虫的胃毒活性和拒食活性,及其对小菜蛾幼虫3种解毒酶活性的影响。研究结果表明,3种溶剂提取GBEE对小菜蛾幼虫均有一定毒杀作用,其中甲醇银杏外种皮提取物对小菜蛾的24 h LC_(50)为216.884 mg/mL,48 h LC_(50)为48.781 mg/mL;12 h AFC_(50)为230.083 mg/mL,24 h AFC_(50)57.560 mg/mL。LC_(50)剂量下处理小菜蛾后,CarE、GSTs和MFO活性引导24 h降低,表现为抑制作用,之后活性诱导升高,表现为激活作用。综上所述,银杏外种皮提取物对小菜蛾具有一定的毒杀作用,主要作用方式为胃毒作用和拒食作用,CarE、GSTs和MFO 3种解毒酶活性表现为先降低后升高。
