title: Evaluation of corn hybrids expressing Cry1F, cry1A.105, Cry2Ab2, Cry34Ab1/Cry35Ab1, and Cry3Bb1 against southern United States insect pests.
abstract: Studies were conducted across the southern United States to characterize the efficacy of multiple Bacillus thuringiensis (Bt) events in a field corn, Zea mays L., hybrid for control of common lepidopteran and coleopteran pests. Cry1F protein in event TC1507 and Cry1A.105 + Cry2Ab2 proteins in event MON 89034 were evaluated against pests infesting corn on above-ground plant tissue including foliage, stalks, and ears. Cry34Ab1/Cry35Ab1 proteins in event DAS-59122-7 and Cry3Bb1 in event MON 88017 were evaluated against the larvae of Mexican corn rootworm, Diabrotica virgifera zeae Krysan and Smith, which occur below-ground. Field corn hybrids containing Cry1F, Cry1A.105 + Cry2Ab2, Cry34Ab1/Cry35Ab1, and Cry3Bb1 insecticidal proteins (SmartStax) consistently demonstrated reductions in plant injury and/or reduced larval survivorship as compared with a non-Bt field corn hybrid. Efficacy provided by a field corn hybrid with multiple Bt proteins was statistically equal to or significantly better than corn hybrids containing a single event active against target pests. Single event field corn hybrids provided very high levels of control of southwestern corn borer, Diatraea grandiosella (Dyar), lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), and fall armyworm, Spodoptera frugiperda (J.E. Smith), and were not significantly different than field corn hybrids with multiple events. Significant increases in efficacy were observed for a field corn hybrid with multiple Bt events for sugarcane borer, Diatraea saccharalis (F.), beet armyworm, Spodoptera exigua (Hübner), corn earworm, Helicoverpa zea (Boddie), and Mexican corn rootworm. Utilization of field corn hybrids containing multiple Bt events provides a means for managing insect resistance to Bt proteins and reduces non-Bt corn refuge requirements.
authors.affiliation: Dow AgroSciences LLC, 753 HWY 438, Greenville, MS 38701, USA. mwillrichsiebert@dow.com
authors.forename: M W
authors.initials: MW
authors.lastname: Siebert
authors.forename: S P
authors.initials: SP
authors.lastname: Nolting
authors.forename: W
authors.initials: W
authors.lastname: Hendrix
authors.forename: S
authors.initials: S
authors.lastname: Dhavala
authors.forename: C
authors.initials: C
authors.lastname: Craig
authors.forename: B R
authors.initials: BR
authors.lastname: Leonard
authors.forename: S D
authors.initials: SD
authors.lastname: Stewart
authors.forename: J
authors.initials: J
authors.lastname: All
authors.forename: F R
authors.initials: FR
authors.lastname: Musser
authors.forename: G D
authors.initials: GD
authors.lastname: Buntin
authors.forename: L
authors.initials: L
authors.lastname: Samuel
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001517:Coleoptera / Q000187:drug effects* / Q000502:physiology; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D005247:Feeding Behavior; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000502:physiology; D009036:Moths / Q000187:drug effects* / Q000502:physiology; D010572:Pest Control, Biological; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D015144:Southeastern United States; D013045:Species Specificity; D018411:Spodoptera / Q000187:drug effects / Q000502:physiology; D013714:Tennessee; D013781:Texas; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; C507666:Cry3Bbl endotoxin, Bacillus thuringiensis; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis