Genetically Modified Maize Resistant to Corn Earworm (Lepidoptera: Noctuidae) in Sinaloa, Mexico (original) (raw)
Related papers
GM crops
Sweet corn, Zea mays L., transformed to express a novel vegetative insecticidal protein, Vip3A (event MIR162, Syngenta Seeds, Inc..), produced by the bacterium, Bacillus thuringiensis (Bt), was evaluated over four field seasons in Maryland and two field seasons in Minnesota for efficacy against the corn earworm, Helicoverpa zea (Boddie). Hybrids expressing the Vip3A protein and pyramided in hybrids also expressing the Cry1Ab Bt protein (event Bt11, ATTRIBUTE(®), Syngenta Seeds, Inc.) were compared to hybrids expressing only Cry1Ab or to genetically similar non-Bt hybrids each year. In addition to H. zea efficacy, results for Ostrinia nubilalis (Hübner) and Spodoptera frugiperda (J.E. Smith) are presented. Over all years and locations, the non-Bt hybrids, without insecticide protection, averaged between 43 and 100% ears infested with a range of 0.24 to 1.74 H. zea larvae per ear. By comparison, in the pyramided Vip3A x Cry1Ab hybrids, no larvae were found and only minimal kernel dama...
Florida Entomologist, 2016
The fall armyworm, Spodoptera frugiperda Smith & Abbot (Lepidoptera: Noctuidae), is a key pest of corn, Zea mays L. (Poales: Poaceae), in Mexico. The development of genetically modified (GM) corn hybrids for resistance to this insect, with the inclusion of several genes coding for proteins Cry1Ab, Vip3Aa20, and mCry3A of Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt), offer an alternative to conventional insecticides to control this pest. Resistance to fall armyworms of the GM corn hybrids Agrisure 3000 GT, Agrisure Viptera 3110, and Agrisure Viptera 3111 was evaluated in 4 locations at Sinaloa for a 3 yr period. Damage evaluation showed that the maize hybrids with the Bt gene insertion were not affected by the fall armyworm as compared with their respective isolines, which were seriously damaged. The results reaffirm the insect control benefits provided by this technology and provide a baseline for resistance management.
Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn
PloS one, 2016
Transgenic corn engineered with genes expressing insecticidal toxins from the bacterium Bacillus thuringiensis (Berliner) (Bt) are now a major tool in insect pest management. With its widespread use, insect resistance is a major threat to the sustainability of the Bt transgenic technology. For all Bt corn expressing Cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, Helicoverpa zea (Boddie), which is more tolerant to the Bt toxins. We present field monitoring data using Cry1Ab (1996-2016) and Cry1A.105+Cry2Ab2 (2010-2016) expressing sweet corn hybrids as in-field screens to measure changes in field efficacy and Cry toxin susceptibility to H. zea. Larvae successfully damaged an increasing proportion of ears, consumed more kernel area, and reached later developmental stages (4th - 6th instars) in both types of Bt hybrids (Cry1Ab-event Bt11, and Cry1A.105+Cry2Ab2-event MON89034) since their commercial introduction. Yearly patterns of H. ze...
Toxins, 2019
The corn earworm, Helicoverpa zea (Boddie), is a major pest of Bacillus thuringiensis (Bt) maize and cotton in the U.S.. Reduced efficacy of Bt plants expressing Cry1 and Cry2 against H. zea has been reported in some areas of the U.S.. In this study, we evaluated the occurrence and ear damage of H. zea on transgenic Bt maize expressing Cry proteins or a combination of Vip3A and Cry proteins in the field in Texas in 2018. We found that the occurrence of H. zea larvae and the viable kernel damage area on the ear were not different between non-Bt maize and Bt maize expressing Cry1A.105+Cry2Ab2 and Cry1Ab+Cry1F proteins. A total of 67.5% of the pyramided Bt maize expressing Cry1Ab+Cry1F+Vip3A was damaged by 2nd–4th instar larvae of H. zea. Diet bioassays showed that the resistance ratio against Vip3Aa51 for H. zea obtained from Cry1Ab+Cry1F+Vip3A maize was 20.4 compared to a field population collected from Cry1F+Cry1A.105+Cry2Ab2 maize. Leaf tissue bioassays showed that 7-day survivorsh...
—The corn earworm, Helicoverpa zea Boddie, is a serious pest of corn. Larval feeding in ear tips destroys kernels and allows growth of fungi and production of mycotoxins. Infested sweet corn is not marketable. Development of improved transgenic hybrids expressing insecticidal toxins from Bacillus thuringiensis (Bt) may limit or prevent crop losses. The effectiveness of Attribute ® II Bt resistance and applications of Voliam Xpress insecticide were evaluated for effectiveness in controlling corn earworm in plots near Urbana, IL, USA, in 2013. Where no insecticides were applied, ear infestations and kernel damage in Attribute ® II 'Protector' plots were consistently lower (near zero) than in plots of the non-Bt isoline 'Garrison.' Multiple applications of Voliam Xpress significantly reduced the number of corn earworm larvae and kernel damage in the Garrison plots, but infestations and damage in these plots were greater than in Protectorplots that did not receive insecticide applications. Our results indicate that Attribute ® II Bt resistance is more effective than multiple applications of an insecticide for preventing losses caused by corn earworm in sweet corn.
EFFECTIVENESS OF TRANSGENIC BT MAIZE TO CONTROL Helicoverpa armigera (LEPIDOPTERA: NOCTUIDAE)
Revista Ciência Agrícola
The caterpillar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), identified in Brazil in 2013, greatly worries farmers because of its destructive power. The technology of transgenic plants that induces resistance to insects is a great ally for controlling caterpillars. In this study we compared the performance of transgenic Bt maize in the controlling of different larval instars of H. armigera in semi-field seedlings. There were tested the following genotypes: (1) Non-Bt maize Iso-hybrid (Control); (2) Cry1F; (3) Cry1F+ Cry1A.105 + Cry2Ab2; (4) Cry1A.105 + Cry2Ab2; (5) Cry1Ab + Cry1F; (6) Cry1Ab + Vip3Aa20. The experimental design was organized in randomized blocks with eight replications, each consisting of a pot with 5 plants artificially infested with larvae of 2 nd , 3 rd or 4 th instar. At 1, 3, 7, 10 and 14 days after infestation, plants were evaluated for defoliation. In the 3 rd instar larvae bioassay, there was high predation by birds, but until seven days after infestation all transgenic maize were efficient to the pest. All transgenic Bt maize were effective in the control of tested H. armigera larvae instars.
Crop Protection, 2013
In the United States, fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a target species of transgenic corn (Zea mays L.) expressing pyramided Bacillus thuringiensis proteins. In 2011, a total of 150 F 2 two-parent families of S. frugiperda were established using single-pair matings of feral individuals collected from three locations in Louisiana and Florida. The objective of this study was to determine the susceptibility of these field derived families of S. frugiperda to a pyramided Bt corn hybrid containing Agrisure Ò VipteraÔ 3111 traits. For each F 2 family, 96 neonates were assayed on leaf tissue of Agrisure Ò VipteraÔ 3111 corn in the laboratory. None of the 150 families survived for 7 days on leaf tissue of the Bt corn plants. The results demonstrate that the field populations of S. frugiperda collected from Louisiana and Florida were susceptible to the pyramided Bt corn product containing Agrisure Ò VipteraÔ 3111 traits. The data generated in this study can be used as baseline data for resistance monitoring.
Journal of Insect Science, 2019
Spodoptera frugiperda (J. E. Smith) is one of the major pests of maize in Argentina. The main tool for its control is the use of genetically modified maize hybrids expressing Bacillus thuringiensis (Bt) insecticidal proteins. Maize growers in Argentina initially controlled this pest with Bt maize that expressed a single Bt protein (Cry1Ab or Cry1F). Currently it is necessary to plant maize cultivars that produce two Bt proteins to achieve the satisfactory control. Recently, Cry1F field-evolved resistant populations of this species were confirmed in Argentina. The objective of this study was to evaluate the performance of S. frugiperda field-collected strains on different Bt and non-Bt maize hybrids. Strains were collected from non-Bt maize (T1), Agrisure TDMax (T2), Agrisure Viptera (T3), Agrisure Viptera 3110 (T4), Genuity VT Triple Pro (T5), and Power Core (T6). Three experiments were performed to 1) determine the survivorship and reproduction of field-collected larvae (F0) from B...
Crop Protection, 2001
Twenty-eight transgenic maize hybrids containing the Bacillus thuringiensis (Bt) endotoxin and several of their non-Bt isolines were evaluated for control of the southwestern corn borer, Diatraea grandiosella Dyar, the European corn borer, Ostrinia nubilalis (HuK bner), and the corn earworm (CEW), Heliocoverpa zea (Boddie) in the shank and ear. The Bt hybrids represented four events (Mon810, Bt11, 176, and CBH354) from seven seed companies. The maize hybrids were grown in four locations that ranged from the northern to southern length of the Texas Panhandle. A semi-arid environment with hot days-cool nights and (220 mm of rain characterize this region. Maize in this region is irrigated with furrow or moving truss application systems. Maize was infested with each species of corn borer at the tasseling growth stage using the Davis applicator. Natural infestations of corn earworm were allowed to develop. Hybrids of events Mon810, Bt11, and CBH354 provided good control of corn borers in shanks and ears. Event 176 hybrids did not provide good control in the shanks and ears because Bt is not expressed in reproductive tissue in this event. No Bt transgenic maize hybrid provided consistent control of CEW larvae on kernels. Feeding gallery length on ears from CEW feeding was sometimes shorter in Mon810 and Bt11 hybrids than in the non-Bt hybrids.