title: Cry1F resistance among lepidopteran pests: a model for improved resistance management?
abstract: The Cry1Fa protein from the bacterium Bacillus thuringiensis (Bt) is known for its potential to control lepidopteran pests, especially through transgenic expression in maize and cotton. The maize event TC1507 expressing the cry1Fa toxin gene became commercially available in the United States in 2003 for the management of key lepidopteran pests including the European corn borer, Ostrinia nubilalis, and the fall armyworm, Spodoptera frugiperda. A high-dose/refuge strategy has been widely adopted to delay evolution of resistance to event TC1507 and other transgenic Bt crops. Efficacy of this strategy depends on the crops expressing a high dose of the Bt toxin to targeted pests and adjacent refuges of non-Bt host plants serving as a source of abundant susceptible insects. While this strategy has proved effective in delaying O. nubilalis resistance, field-evolved resistance to event TC1507 has been reported in S. frugiperda populations in Puerto Rico, Brazil, and the southeastern United States. This paper examines available information on resistance to Cry1Fa in O. nubilalis and S. frugiperda and discusses how this information identifies opportunities to refine resistance management recommendations for Bt maize.
authors.affiliation: University of Nebraska-Lincoln, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States. Electronic address: avelezarango2@unl.edu.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Vélez
authors.affiliation: University of Nebraska-Lincoln, Department of Entomology, 103 Entomology Hall, Lincoln, NE 68583-0816, United States.
authors.forename: Neetha Nanoth
authors.initials: NN
authors.lastname: Vellichirammal
authors.affiliation: University of Tennessee, Department of Entomology and Plant Pathology, Plant Biotechnology Building, Knoxville, TN 37996, United States.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Jurat-Fuentes
authors.affiliation: University of Florida, Entomology and Nematology Department, Charles Steinmetz Hall, PO Box 110620, Gainesville, FL 32611-0620, United States.
authors.forename: Blair D
authors.initials: BD
authors.lastname: Siegfried
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000494:pharmacology*; D001938:Brazil; D007915:Lepidoptera / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics; D011647:Puerto Rico; D015144:Southeastern United States
chemical_list: D001426:Bacterial Proteins