title: Selection and characterization of resistance to the Vip3Aa20 protein from Bacillus thuringiensis in Spodoptera frugiperda.
abstract: BACKGROUND
  Spodoptera frugiperda is one the main target pests of maize events expressing Vip3Aa20 protein from Bacillus thuringiensis (Bt) in Brazil. In this study, we selected a resistant strain of S. frugiperda on Bt maize expressing Vip3Aa20 protein and characterized the inheritance and fitness costs of the resistance.
  
  
  RESULTS
  The resistance ratio of the Vip3Aa20-resistant strain of S. frugiperda was >3200-fold. Neonates of the Vip3Aa20-resistant strain were able to survive and emerge as fertile adults on Vip3Aa20 maize, while larvae from susceptible and heterozygous strains did not survive. The inheritance of Vip3Aa20 resistance was autosomal recessive and monogenic. Life history studies to investigate fitness cost revealed an 11% reduction in the survival rate until adult stage and a ∼50% lower reproductive rate of the Vip3Aa20-resistant strain compared with susceptible and heterozygous strains.
  
  
  CONCLUSIONS
  This is the first characterization of S. frugiperda resistance to Vip3Aa protein. Our results provide useful information for resistance management programs designed to prevent or delay resistance evolution to Vip3Aa proteins in S. frugiperda. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Oderlei
authors.initials: O
authors.lastname: Bernardi
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bernardi
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Renato J
authors.initials: RJ
authors.lastname: Horikoshi
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Okuma
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Leonardo L
authors.initials: LL
authors.lastname: Miraldo
authors.affiliation: Syngenta Crop Protection, São Paulo, Brazil.
authors.forename: Julio
authors.initials: J
authors.lastname: Fatoretto
authors.affiliation: Syngenta Crop Protection, São Paulo, Brazil.
authors.forename: Fernanda Cl
authors.initials: FC
authors.lastname: Medeiros
authors.affiliation: Syngenta Crop Protection, Greensboro, NC, USA.
authors.forename: Tony
authors.initials: T
authors.lastname: Burd
authors.affiliation: Department of Entomology and Acarology, University of São Paulo (ESALQ/USP), Piracicaba, São Paulo, Brazil.
authors.forename: Celso
authors.initials: C
authors.lastname: Omoto
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D001938:Brazil; D005260:Female; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D010063:Ovum / Q000187:drug effects / Q000254:growth & development; D011679:Pupa / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D012641:Selection, Genetic; D018411:Spodoptera / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D003313:Zea mays / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D007306:Insecticides; C447139:Vip3A protein, Bacillus thuringiensis
keywords: Bt maize; Vip proteins; fall armyworm; inheritance of resistance; resistance management