Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems. Some plant species may be hosts or provide resources to some pest species...Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems. Some plant species may be hosts or provide resources to some pest species. We assessed the risks and benefits of sesame （Sesamum indicum L.）, as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems. Our results showed that the mean Iongevities of arthropod parasitoids Pteromalus puparum （L.）, Encarsia sophia （Girault ＆ Dodd） and male Microplitis tuberculifer （Wesmael） were significantly extended when fed on sesame flowers compared to the water control. Sesame flowers had no effect on adult Iongevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella （L.） females laid more eggs when fed on sesame flowers. It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes. Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.展开更多
To provide pest technicians with a convenient way to recognize insects,a novel method is proposed to classify insect images by integrated region matching (IRM) and dual tree complex wavelet transform (DTCWT).The wing ...To provide pest technicians with a convenient way to recognize insects,a novel method is proposed to classify insect images by integrated region matching (IRM) and dual tree complex wavelet transform (DTCWT).The wing image of the lepidopteran insect is preprocessed to obtain the region of interest (ROI) whose position is then calibrated.The ROI is first segmented with the k-means algorithm into regions according to the color features,properties of all the segmented regions being used as a coarse level feature.The color image is then converted to a grayscale image,where DTCWT features are extracted as a fine level feature.The IRM scheme is undertaken to find K nearest neighbors (KNNs),out of which the nearest neighbor is searched by computing the Canberra distance of DTCWT features.The method was tested with a database including 100 lepidopteran insect species from 18 families and the recognition accuracy was 84.47%.For the forewing subset,a recognition accuracy of 92.38% was achieved.The results showed that the proposed method can effectively solve the problem of automatic species identification of lepidopteran specimens.展开更多
[Objective] The paper was to improve the efficiency and accuracy of early forecast of Lepidopteran oak-infesting pests.[Method] DNA barcoding technique was established for quick species identification using mitochondr...[Objective] The paper was to improve the efficiency and accuracy of early forecast of Lepidopteran oak-infesting pests.[Method] DNA barcoding technique was established for quick species identification using mitochondrial cytochrome C oxidase subunit Ⅰ（COⅠ） as the standard gene.This barcoding technique was used to amplify and sequence genomic DNA samples from eggs and pupae of 11 species of Lepidopteran pests collected from oak.[Result] The DNA barcoding standard genes of 594-708 bp were determined from eggs and pupae of Lepidopteran insects.There were differences of 0-2 bases in DNA barcode sequences between conspecific eggs and pupae,with the sequence identity of 99.7%-100%.The average content of A,T,G and C of DNA barcode sequences from Lepidopteran insects were 30.7%,38.5%,14.9% and 15.9%,respectively.The obtained DNA barcode sequences had 91.4%-100% identity and 0-8.6% difference degree with GenBank-deposited DNA barcode sequences from organisms of the genetically-closest relationship.Among them,DNA barcode sequences from egg and pupa samples of 10 Lepidopteran insects（No.1-20） had 99%-100% identity and 0-1.0% difference degree with homologous sequences in GenBank database,while the remaining samples（No.21-22） had high difference degree（8.6%） with homologous sequences.[Conclusion] The established DNA barcoding technique is an effeetive tool for species identification of Lepidopteran pests using genomic DNA from eggs and pupae of Lepidopteran insects.展开更多
A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduce...A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.展开更多
Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, al...Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, allowed us to suggest the mode of action of ACG in the membrane. Our study emphasizes the role of the flanking OH and acetyl groups of THF with the membrane hydrophilic polar head groups. They are essential structural factors in the ACG that facilitate the intermolecular interaction that dehydrates the membrane and makes it potentially toxic against Spodoptera frugiperda.展开更多
The seasonal fluctuation oflepidoptcran cereal stemborers on maize and wild host plants （i.e., grasses and a few sedges） was investigated in southern Benin from 1988 to 1998 by time series analysis and repeated-meas...The seasonal fluctuation oflepidoptcran cereal stemborers on maize and wild host plants （i.e., grasses and a few sedges） was investigated in southern Benin from 1988 to 1998 by time series analysis and repeated-measures analysis of variance （ANOVA）. In addition, a walk-in light trap was used to study the flight behavior of adult moths. On both cereals and grasses, the noctuid Sesamia calaraistis was the predominant species, followed by the pyralid Eldana saccharina. The noctuid Busseolafusca was rare on both maize and wild host plants. In general, pest populations increased during the course of the year to reach peak densities during the second short rainy season, and then crashed to close to zero during the dry season. On wild host plants, egg masses and other immature stages were collected throughout the year but they were higher on wild grasses than maize during the off-season. Thus wild host plants can be considered as refuge for both borers and natural enemies during the off-season, when maize is not available. However, only four out of the eleven wild host species played a discernable role. S. calamistis egg densities appeared to be influenced by density-dependent factors, suggesting an effect of natural enemies. Temperature and rainfall had a negative effect on egg abundance. Larval parasitism by a Kenyan strain of the braconid Cotesia sesamiae, which was released in southern Benin in the early 1990s, and by the tachinid Sturmiopsisparasitica varied between seasons and years but there were no discernable patterns. For both parasitoids and borer host species, parasitism was positively correlated with trap catches of adult moths. The recovery of C. sesamiae during a 2-year period suggests that the parasitoid has established its population in southern Benin.展开更多
[Objective]The paper was to screen out effective insecticides against main lepidopteran pests of cauliflower.[Method]Field trials were carried out in 2018,and 11 treatments were designed in the test.The population dec...[Objective]The paper was to screen out effective insecticides against main lepidopteran pests of cauliflower.[Method]Field trials were carried out in 2018,and 11 treatments were designed in the test.The population decline rate and corrected control effect were calculated.[Result]16%Indoxacarb+tebufenozide EC and 35%methoxyfenozide+indoxacarb SC had quick bioactivity and persistence,and the control effects at 1 and 10 d post spraying were greater than 85%.11%Emamectin benzoate+lufenuron ME,1 billion PIB/mL of Autographa californica NPV SC and 10%alpha-cypermethrin+lufenuron EC had good persistence,and the control effect at 10 d post spraying was greater than 90%.[Conclusion]Compound preparations of indoxacarb and tebufenozide or methoxyfenozide are recommended for controlling lepidopteran pests of cauliflower.展开更多
The cotton bollworm Helicoverpa armigera and the oriental tobacco budworm H. assulta are sibling species, both being important agricultural pests. Morphologically, the two insects are almost indistinguishable at the e...The cotton bollworm Helicoverpa armigera and the oriental tobacco budworm H. assulta are sibling species, both being important agricultural pests. Morphologically, the two insects are almost indistinguishable at the egg, larval and pupal stages. One of the big challenges in the study of these insects, in particular in integrated pest management, is a timely and dependable identification of these insects at their early stages of development. Here, we report a H. armigera-specific nuclear DNA marker, and demonstrate that it can be employed to reliably discriminate between 1-1. armigera and 11. assulta by simple polymerase chain reaction amplification experiment.展开更多
Ecological impact caused by transgene flow from genetically engineered （GE） crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for...Ecological impact caused by transgene flow from genetically engineered （GE） crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for the eco- logical risk assessment prior to the commercialization of GE crops. We produced F1 and F2 hybrid descendants from crosses of two insect-resistant GE rice lines （Bt, Bt/CpT1） and their non-GE rice parent with a wild rice （Oryza ruff- pogon） population to estimate the transgenic fitness. Insect damages and life-cycle fitness of GE and non-GE crop- wild hybrid descendants as well as their wild parent were examined in a common-garden experiment. No significant differences in insect damages were observed between the wild rice parent and GE hybrid descendants under high- insect pressure. The wild parent showed significantly greater relative survival-regeneration ratios than its GE and non-GE hybrid descendants under both high- and low-in- sect pressure. However, more seeds were produced in GE hybrid descendants than their non-GE counterparts under high-insect pressure. Given that the introduction of Bt and Bt/CpT1 transgenes did not provide greater insect resistance to crop-wild hybrid descendants than their wild parent, we predict that transgene flow from GE insect-resistant rice to wild rice populations may not cause considerable ecolog- ical risks.展开更多
Weeds and insect pests are two important biotic stresses resulting in yield loss in rice, and wide compatibility is the essential characteristic of breeding inter-subspecific hybrid rice. This study focused on glyphos...Weeds and insect pests are two important biotic stresses resulting in yield loss in rice, and wide compatibility is the essential characteristic of breeding inter-subspecific hybrid rice. This study focused on glyphosate resistance, lepidopteran resistance and wide compatibility as well as identification of molecular and some agronomic characteristics of transgenic male sterile line E1 C4008 S. The results indicated that glyphosate resistance gene Epsps^# and lepidopteran resistance gene Cry1 ca^# were transferred into japonica wide compatibility male sterile line 4008 S by Agrobacterium-mediated method, and four independent transformation events named E1 C4008 S-1, E1 C4008 S-2, E1 C4008 S-3 and E1 C4008 S-4 were obtained, in which E1 C4008 S-3 and E1 C4008 S-4 were of single copy insertion. The EPSPS protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 300.58 to 1410.69 μg/g at the tillering stage. The glyphosate tolerable concentration(dosage) of E1 C4008 S-3 and E1 C4008 S-4 reached at least 16 g/L(54.42 kg/hm^2), and the seeds of E1 C4008 S-4 can germinate normally on the medium containing 1 g/L glyphosate. The CRY1 C protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 0.62 to 2.43 μg/g at the tillering stage. The larvae mortalities of rice leaf rollers fed on leaves of E1 C4008 S-3 and E1 C4008 S-4 for 5 d were 95.35% and 97.77%, respectively, while the average mortalities of silkworms fed with protein extracts from leaves of E1 C4008 S-3 and E1 C4008 S-4 reached 94.55% and 83.64%, respectively. The results suggested that wide compatibility and evaluated agronomic traits of E1 C4008 S-4 were not significantly changed by insertion of the exogenous genes. Overall, a novel male sterile germplasm with glyphosate resistance, lepidopteran resistance and wide compatibility was verified to be dev展开更多
Objective:To evaluate the antifeedant and larvicidal activities of dichloromethane(DCM),acetone,dimethylsulfoxide(DMSO)and aqueous extracts of Spilanthes acmella(S.acmella)leaves against Earias vitella,Helicoverpa arm...Objective:To evaluate the antifeedant and larvicidal activities of dichloromethane(DCM),acetone,dimethylsulfoxide(DMSO)and aqueous extracts of Spilanthes acmella(S.acmella)leaves against Earias vitella,Helicoverpa armigera and Spodoptera litura.Methods:DCM,acetone,DMSO and aqueous extracts were studied using fruit and leaf discs no-choice method at 0.625%,1.25%,2.5%and 5%concentration.Results:All the extracts showed antifeedant and larvicidal activities against all the tested insects.However,maximum antifeedant activity was detected in DCM extract of S.acmella against all tested pest,followed by acetone,DMSO and aqueous extracts at 5%concentration.The leaves extract of S.acmella also showed larvicidal activity;maximum larval mortality was observed in DCM extract against Helicoverpa armigera(48.88%),Spodoptera litura(44.88%)and Earias vitella(75.11%)followed by acetone,DMSO and aqueous extracts at 5%concentration.Conclusions:DCM extract of S.acmella could be further purified to develop a formulation for eco-friendly pest control agent.展开更多
基金funded by the Zhejiang Key Research and Development Program,China(2015C02014)the earmarked fund for China Agriculture Research System(CARS-01-17)
文摘Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems. Some plant species may be hosts or provide resources to some pest species. We assessed the risks and benefits of sesame （Sesamum indicum L.）, as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems. Our results showed that the mean Iongevities of arthropod parasitoids Pteromalus puparum （L.）, Encarsia sophia （Girault ＆ Dodd） and male Microplitis tuberculifer （Wesmael） were significantly extended when fed on sesame flowers compared to the water control. Sesame flowers had no effect on adult Iongevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella （L.） females laid more eggs when fed on sesame flowers. It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes. Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.
基金Project (No.2006AA10Z211) supported by the National High-Tech Research and Development Program (863) of China
文摘To provide pest technicians with a convenient way to recognize insects,a novel method is proposed to classify insect images by integrated region matching (IRM) and dual tree complex wavelet transform (DTCWT).The wing image of the lepidopteran insect is preprocessed to obtain the region of interest (ROI) whose position is then calibrated.The ROI is first segmented with the k-means algorithm into regions according to the color features,properties of all the segmented regions being used as a coarse level feature.The color image is then converted to a grayscale image,where DTCWT features are extracted as a fine level feature.The IRM scheme is undertaken to find K nearest neighbors (KNNs),out of which the nearest neighbor is searched by computing the Canberra distance of DTCWT features.The method was tested with a database including 100 lepidopteran insect species from 18 families and the recognition accuracy was 84.47%.For the forewing subset,a recognition accuracy of 92.38% was achieved.The results showed that the proposed method can effectively solve the problem of automatic species identification of lepidopteran specimens.
基金Supported by Natural Science Foundation of Liaoning Province(2014027002)National Special Fund for Development of Cocoon Silk(201601)National Modern Agriculture Industry Technology System Construction Project(CARS-18)
文摘[Objective] The paper was to improve the efficiency and accuracy of early forecast of Lepidopteran oak-infesting pests.[Method] DNA barcoding technique was established for quick species identification using mitochondrial cytochrome C oxidase subunit Ⅰ（COⅠ） as the standard gene.This barcoding technique was used to amplify and sequence genomic DNA samples from eggs and pupae of 11 species of Lepidopteran pests collected from oak.[Result] The DNA barcoding standard genes of 594-708 bp were determined from eggs and pupae of Lepidopteran insects.There were differences of 0-2 bases in DNA barcode sequences between conspecific eggs and pupae,with the sequence identity of 99.7%-100%.The average content of A,T,G and C of DNA barcode sequences from Lepidopteran insects were 30.7%,38.5%,14.9% and 15.9%,respectively.The obtained DNA barcode sequences had 91.4%-100% identity and 0-8.6% difference degree with GenBank-deposited DNA barcode sequences from organisms of the genetically-closest relationship.Among them,DNA barcode sequences from egg and pupa samples of 10 Lepidopteran insects（No.1-20） had 99%-100% identity and 0-1.0% difference degree with homologous sequences in GenBank database,while the remaining samples（No.21-22） had high difference degree（8.6%） with homologous sequences.[Conclusion] The established DNA barcoding technique is an effeetive tool for species identification of Lepidopteran pests using genomic DNA from eggs and pupae of Lepidopteran insects.
文摘A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.
文摘Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, allowed us to suggest the mode of action of ACG in the membrane. Our study emphasizes the role of the flanking OH and acetyl groups of THF with the membrane hydrophilic polar head groups. They are essential structural factors in the ACG that facilitate the intermolecular interaction that dehydrates the membrane and makes it potentially toxic against Spodoptera frugiperda.
文摘The seasonal fluctuation oflepidoptcran cereal stemborers on maize and wild host plants （i.e., grasses and a few sedges） was investigated in southern Benin from 1988 to 1998 by time series analysis and repeated-measures analysis of variance （ANOVA）. In addition, a walk-in light trap was used to study the flight behavior of adult moths. On both cereals and grasses, the noctuid Sesamia calaraistis was the predominant species, followed by the pyralid Eldana saccharina. The noctuid Busseolafusca was rare on both maize and wild host plants. In general, pest populations increased during the course of the year to reach peak densities during the second short rainy season, and then crashed to close to zero during the dry season. On wild host plants, egg masses and other immature stages were collected throughout the year but they were higher on wild grasses than maize during the off-season. Thus wild host plants can be considered as refuge for both borers and natural enemies during the off-season, when maize is not available. However, only four out of the eleven wild host species played a discernable role. S. calamistis egg densities appeared to be influenced by density-dependent factors, suggesting an effect of natural enemies. Temperature and rainfall had a negative effect on egg abundance. Larval parasitism by a Kenyan strain of the braconid Cotesia sesamiae, which was released in southern Benin in the early 1990s, and by the tachinid Sturmiopsisparasitica varied between seasons and years but there were no discernable patterns. For both parasitoids and borer host species, parasitism was positively correlated with trap catches of adult moths. The recovery of C. sesamiae during a 2-year period suggests that the parasitoid has established its population in southern Benin.
文摘[Objective]The paper was to screen out effective insecticides against main lepidopteran pests of cauliflower.[Method]Field trials were carried out in 2018,and 11 treatments were designed in the test.The population decline rate and corrected control effect were calculated.[Result]16%Indoxacarb+tebufenozide EC and 35%methoxyfenozide+indoxacarb SC had quick bioactivity and persistence,and the control effects at 1 and 10 d post spraying were greater than 85%.11%Emamectin benzoate+lufenuron ME,1 billion PIB/mL of Autographa californica NPV SC and 10%alpha-cypermethrin+lufenuron EC had good persistence,and the control effect at 10 d post spraying was greater than 90%.[Conclusion]Compound preparations of indoxacarb and tebufenozide or methoxyfenozide are recommended for controlling lepidopteran pests of cauliflower.
文摘The cotton bollworm Helicoverpa armigera and the oriental tobacco budworm H. assulta are sibling species, both being important agricultural pests. Morphologically, the two insects are almost indistinguishable at the egg, larval and pupal stages. One of the big challenges in the study of these insects, in particular in integrated pest management, is a timely and dependable identification of these insects at their early stages of development. Here, we report a H. armigera-specific nuclear DNA marker, and demonstrate that it can be employed to reliably discriminate between 1-1. armigera and 11. assulta by simple polymerase chain reaction amplification experiment.
基金supported by the National Natural Science Foundation of China (31330014)the National Program of Development of Transgenic New Species of China (2016ZX08011006)
文摘Ecological impact caused by transgene flow from genetically engineered （GE） crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for the eco- logical risk assessment prior to the commercialization of GE crops. We produced F1 and F2 hybrid descendants from crosses of two insect-resistant GE rice lines （Bt, Bt/CpT1） and their non-GE rice parent with a wild rice （Oryza ruff- pogon） population to estimate the transgenic fitness. Insect damages and life-cycle fitness of GE and non-GE crop- wild hybrid descendants as well as their wild parent were examined in a common-garden experiment. No significant differences in insect damages were observed between the wild rice parent and GE hybrid descendants under high- insect pressure. The wild parent showed significantly greater relative survival-regeneration ratios than its GE and non-GE hybrid descendants under both high- and low-in- sect pressure. However, more seeds were produced in GE hybrid descendants than their non-GE counterparts under high-insect pressure. Given that the introduction of Bt and Bt/CpT1 transgenes did not provide greater insect resistance to crop-wild hybrid descendants than their wild parent, we predict that transgene flow from GE insect-resistant rice to wild rice populations may not cause considerable ecolog- ical risks.
基金funded by National Major Science and Technology Project on Breeding of New Genetically Modified Organisms(Grant No.2016ZX-08001003-001)。
文摘Weeds and insect pests are two important biotic stresses resulting in yield loss in rice, and wide compatibility is the essential characteristic of breeding inter-subspecific hybrid rice. This study focused on glyphosate resistance, lepidopteran resistance and wide compatibility as well as identification of molecular and some agronomic characteristics of transgenic male sterile line E1 C4008 S. The results indicated that glyphosate resistance gene Epsps^# and lepidopteran resistance gene Cry1 ca^# were transferred into japonica wide compatibility male sterile line 4008 S by Agrobacterium-mediated method, and four independent transformation events named E1 C4008 S-1, E1 C4008 S-2, E1 C4008 S-3 and E1 C4008 S-4 were obtained, in which E1 C4008 S-3 and E1 C4008 S-4 were of single copy insertion. The EPSPS protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 300.58 to 1410.69 μg/g at the tillering stage. The glyphosate tolerable concentration(dosage) of E1 C4008 S-3 and E1 C4008 S-4 reached at least 16 g/L(54.42 kg/hm^2), and the seeds of E1 C4008 S-4 can germinate normally on the medium containing 1 g/L glyphosate. The CRY1 C protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 0.62 to 2.43 μg/g at the tillering stage. The larvae mortalities of rice leaf rollers fed on leaves of E1 C4008 S-3 and E1 C4008 S-4 for 5 d were 95.35% and 97.77%, respectively, while the average mortalities of silkworms fed with protein extracts from leaves of E1 C4008 S-3 and E1 C4008 S-4 reached 94.55% and 83.64%, respectively. The results suggested that wide compatibility and evaluated agronomic traits of E1 C4008 S-4 were not significantly changed by insertion of the exogenous genes. Overall, a novel male sterile germplasm with glyphosate resistance, lepidopteran resistance and wide compatibility was verified to be dev
基金Supported by Department of Science&Technology(DST),Division of Science and Engineering Research Board(SERB)(Grant No.SERC/LS−0412/2010).
文摘Objective:To evaluate the antifeedant and larvicidal activities of dichloromethane(DCM),acetone,dimethylsulfoxide(DMSO)and aqueous extracts of Spilanthes acmella(S.acmella)leaves against Earias vitella,Helicoverpa armigera and Spodoptera litura.Methods:DCM,acetone,DMSO and aqueous extracts were studied using fruit and leaf discs no-choice method at 0.625%,1.25%,2.5%and 5%concentration.Results:All the extracts showed antifeedant and larvicidal activities against all the tested insects.However,maximum antifeedant activity was detected in DCM extract of S.acmella against all tested pest,followed by acetone,DMSO and aqueous extracts at 5%concentration.The leaves extract of S.acmella also showed larvicidal activity;maximum larval mortality was observed in DCM extract against Helicoverpa armigera(48.88%),Spodoptera litura(44.88%)and Earias vitella(75.11%)followed by acetone,DMSO and aqueous extracts at 5%concentration.Conclusions:DCM extract of S.acmella could be further purified to develop a formulation for eco-friendly pest control agent.
