{"title":"原生芽孢杆菌分离株单独及联合防治秋粘虫不同幼虫的效果","authors":"J. Karshanal, Vinay Kumari Kalia","doi":"10.1186/s41938-023-00743-7","DOIUrl":null,"url":null,"abstract":"Abstract Background Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) Lepidoptera: Noctuidae is an invasive polyphagous pest that causes severe damage to several agricultural crops. The use of pesticides is limited because of their mode of feeding and resistant development. Hence, the present work aimed to determine the pathogenicity of entomopathogenic bacteria ( Bacillus spp.) against FAW in terms of mortality and growth inhibition. In this study, initially 49 native Bacillus isolates, isolated from diverse habitats in India, along with five reference strains, were screened for their efficacy against neonates of S. frugiperda under controlled laboratory conditions, followed by virulence and combinatorial bioassays. Results Five native Bacillus isolates (VKK1, VKK5, S16C2, S25C1, and SOIL 20) showed mortality in the range of 35.49–65.52% against neonates of S. frugiperda at single concentration (1000 μg g −1 of diet). These five isolates, along with one reference strain Btk -HD1 ( Bacillus thuringiensis serovar kurstaki strain HD1), were further tested to find the median lethal concentration (LC 50 ) for neonates of S. frugiperda . Among these, native Bt strain VKK5 showed the lowest LC 50 (718.40 µg/g of diet) and HD1 showed the highest LC 50 (3352 µg/g of diet). Combinatorial bioassay against neonate and third instar larvae showed that the combination of VKK5 and VKK1 had an additive effect. Moreover, growth inhibition was also recorded. Conclusion The combination of Bt strains leads to an enhancement of pathogenicity toward FAW larvae at the initial stage of development, and in later stages, it affects their growth and development. Thus, biocontrol of FAW by entomopathogenic bacteria ( Bt ) can play a vital role in the effective management of FAW.","PeriodicalId":11514,"journal":{"name":"Egyptian Journal of Biological Pest Control","volume":"39 1","pages":"0"},"PeriodicalIF":2.1000,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Efficacy of native Bacillus isolates against different larval instars of fall armyworm, Spodoptera frugiperda alone and in combination\",\"authors\":\"J. Karshanal, Vinay Kumari Kalia\",\"doi\":\"10.1186/s41938-023-00743-7\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract Background Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) Lepidoptera: Noctuidae is an invasive polyphagous pest that causes severe damage to several agricultural crops. The use of pesticides is limited because of their mode of feeding and resistant development. Hence, the present work aimed to determine the pathogenicity of entomopathogenic bacteria ( Bacillus spp.) against FAW in terms of mortality and growth inhibition. In this study, initially 49 native Bacillus isolates, isolated from diverse habitats in India, along with five reference strains, were screened for their efficacy against neonates of S. frugiperda under controlled laboratory conditions, followed by virulence and combinatorial bioassays. Results Five native Bacillus isolates (VKK1, VKK5, S16C2, S25C1, and SOIL 20) showed mortality in the range of 35.49–65.52% against neonates of S. frugiperda at single concentration (1000 μg g −1 of diet). These five isolates, along with one reference strain Btk -HD1 ( Bacillus thuringiensis serovar kurstaki strain HD1), were further tested to find the median lethal concentration (LC 50 ) for neonates of S. frugiperda . Among these, native Bt strain VKK5 showed the lowest LC 50 (718.40 µg/g of diet) and HD1 showed the highest LC 50 (3352 µg/g of diet). Combinatorial bioassay against neonate and third instar larvae showed that the combination of VKK5 and VKK1 had an additive effect. Moreover, growth inhibition was also recorded. Conclusion The combination of Bt strains leads to an enhancement of pathogenicity toward FAW larvae at the initial stage of development, and in later stages, it affects their growth and development. Thus, biocontrol of FAW by entomopathogenic bacteria ( Bt ) can play a vital role in the effective management of FAW.\",\"PeriodicalId\":11514,\"journal\":{\"name\":\"Egyptian Journal of Biological Pest Control\",\"volume\":\"39 1\",\"pages\":\"0\"},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2023-10-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Egyptian Journal of Biological Pest Control\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1186/s41938-023-00743-7\",\"RegionNum\":3,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENTOMOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Egyptian Journal of Biological Pest Control","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1186/s41938-023-00743-7","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENTOMOLOGY","Score":null,"Total":0}
Efficacy of native Bacillus isolates against different larval instars of fall armyworm, Spodoptera frugiperda alone and in combination
Abstract Background Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) Lepidoptera: Noctuidae is an invasive polyphagous pest that causes severe damage to several agricultural crops. The use of pesticides is limited because of their mode of feeding and resistant development. Hence, the present work aimed to determine the pathogenicity of entomopathogenic bacteria ( Bacillus spp.) against FAW in terms of mortality and growth inhibition. In this study, initially 49 native Bacillus isolates, isolated from diverse habitats in India, along with five reference strains, were screened for their efficacy against neonates of S. frugiperda under controlled laboratory conditions, followed by virulence and combinatorial bioassays. Results Five native Bacillus isolates (VKK1, VKK5, S16C2, S25C1, and SOIL 20) showed mortality in the range of 35.49–65.52% against neonates of S. frugiperda at single concentration (1000 μg g −1 of diet). These five isolates, along with one reference strain Btk -HD1 ( Bacillus thuringiensis serovar kurstaki strain HD1), were further tested to find the median lethal concentration (LC 50 ) for neonates of S. frugiperda . Among these, native Bt strain VKK5 showed the lowest LC 50 (718.40 µg/g of diet) and HD1 showed the highest LC 50 (3352 µg/g of diet). Combinatorial bioassay against neonate and third instar larvae showed that the combination of VKK5 and VKK1 had an additive effect. Moreover, growth inhibition was also recorded. Conclusion The combination of Bt strains leads to an enhancement of pathogenicity toward FAW larvae at the initial stage of development, and in later stages, it affects their growth and development. Thus, biocontrol of FAW by entomopathogenic bacteria ( Bt ) can play a vital role in the effective management of FAW.
期刊介绍:
The Egyptian Journal of Biological Pest Control is a periodic scientific journal published by the Egyptian Society for Biological Control of Pests (ESBCP) in collaboration with SpringerNature. The journal aims to publish internationally peer-reviewed, high-quality research articles in the field of biological and integrated pest control (non-chemical control). The journal publishes review articles, original papers, conference reports, book reviews, editorials, laboratory reports, technical notes and short communications.