Carolina Manzano, M Alejandro Vera, Augusto S Casmuz, Erica Luft Albarracin, Gerardo Gastaminza, María Gabriela Murúa
{"title":"Fitness and mating compatibility of <i>Rachiplusia nu</i> strains exposed to soybean expressing Cry1Ac in Argentina.","authors":"Carolina Manzano, M Alejandro Vera, Augusto S Casmuz, Erica Luft Albarracin, Gerardo Gastaminza, María Gabriela Murúa","doi":"10.1017/S0007485325000069","DOIUrl":null,"url":null,"abstract":"<p><p><i>Rachiplusia nu</i> (Guenée) (Lepidoptera: Noctuidae) is a significant agricultural pest in South America infesting several crops, including soybeans. <i>Bacillus thuringiensis</i> (Berliner) (Bt) soybean, expressing Cry1Ac protein, is widely planted as a control method for numerous lepidopteran pests. However, insect resistance to Bt proteins poses a threat to its sustainability. Recent field reports from Argentina, Uruguay, and Brazil have documented unexpected injury to Bt soybean caused by <i>R. nu</i> populations, which may indicate the development of resistance to Cry1Ac in this species. This study aimed to evaluate the biological performance, reproductive parameters, and reproductive compatibility of two <i>R. nu</i> strains, one susceptible (SS) and the other exhibiting reduced susceptibility to Bt toxin (RR), when reared on Bt and non-Bt soybean. Reproductive compatibility between strains was investigated through parental and hybrid crosses, evaluating fecundity, fertility, and mating success. SS larvae fed with Bt soybean failed to complete their life cycle, whereas RR larvae exhibited higher survival rates. Egg and larval stages of RR larvae were longer when reared on Bt soybean. Pupal mass was lower for Bt-fed resistant strain, although this did not reflect on fecundity and longevity. Results on parental crosses revealed that Bt-fed RR strain displayed reduced mating success, fecundity, and fertility, compared to the non-Bt treatment. Hybrid crosses showed evidence for prezygotic and postzygotic incompatibility. These results suggest a shift in susceptibility of <i>R. nu</i> to Cry1Ac protein and highlight the importance of implementing robust insect resistance management strategies to maintain the effectiveness of Bt crops.</p>","PeriodicalId":9370,"journal":{"name":"Bulletin of Entomological Research","volume":" ","pages":"1-9"},"PeriodicalIF":1.6000,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Entomological Research","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1017/S0007485325000069","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENTOMOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) is a significant agricultural pest in South America infesting several crops, including soybeans. Bacillus thuringiensis (Berliner) (Bt) soybean, expressing Cry1Ac protein, is widely planted as a control method for numerous lepidopteran pests. However, insect resistance to Bt proteins poses a threat to its sustainability. Recent field reports from Argentina, Uruguay, and Brazil have documented unexpected injury to Bt soybean caused by R. nu populations, which may indicate the development of resistance to Cry1Ac in this species. This study aimed to evaluate the biological performance, reproductive parameters, and reproductive compatibility of two R. nu strains, one susceptible (SS) and the other exhibiting reduced susceptibility to Bt toxin (RR), when reared on Bt and non-Bt soybean. Reproductive compatibility between strains was investigated through parental and hybrid crosses, evaluating fecundity, fertility, and mating success. SS larvae fed with Bt soybean failed to complete their life cycle, whereas RR larvae exhibited higher survival rates. Egg and larval stages of RR larvae were longer when reared on Bt soybean. Pupal mass was lower for Bt-fed resistant strain, although this did not reflect on fecundity and longevity. Results on parental crosses revealed that Bt-fed RR strain displayed reduced mating success, fecundity, and fertility, compared to the non-Bt treatment. Hybrid crosses showed evidence for prezygotic and postzygotic incompatibility. These results suggest a shift in susceptibility of R. nu to Cry1Ac protein and highlight the importance of implementing robust insect resistance management strategies to maintain the effectiveness of Bt crops.
期刊介绍:
Established in 1910, the internationally recognised Bulletin of Entomological Research aims to further global knowledge of entomology through the generalisation of research findings rather than providing more entomological exceptions. The Bulletin publishes high quality and original research papers, ''critiques'' and review articles concerning insects or other arthropods of economic importance in agriculture, forestry, stored products, biological control, medicine, animal health and natural resource management. The scope of papers addresses the biology, ecology, behaviour, physiology and systematics of individuals and populations, with a particular emphasis upon the major current and emerging pests of agriculture, horticulture and forestry, and vectors of human and animal diseases. This includes the interactions between species (plants, hosts for parasites, natural enemies and whole communities), novel methodological developments, including molecular biology, in an applied context. The Bulletin does not publish the results of pesticide testing or traditional taxonomic revisions.