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Browsing by Author "Lorenz, Gus"

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    Effects of transgenic Bacillus thuringiensis cotton on insecticide use, heliothine counts, plant damage, and cotton yield: A meta-analysis, 1996-2015
    Fleming, Daniel; Musser, Fred; Reisig, Dominic; Greene, Jeremy K.; Taylor, Sally V.; Parajulee, Megha; Lorenz, Gus; Catchot, Angus; Gore, Jeffrey; Kerns, David; Stewart, Scott; Boykin, Deborah; Caprio, Michael; Little, Nathan (PLOS, 2018-07-19)
    The primary management tactic for lepidopteran pests of cotton in the United States of America (USA) is the use of transgenic cotton that produces Bacillus thuringiensis Berliner (Bt) toxins. The primary target pests of this technology are Helicoverpa zea (Boddie) and Heliothis virescens (F.) in the eastern and central Cotton Belt of the USA. Concerns over the evolution of resistance in H. zea to Bt toxins and scrutiny of the necessity of Btcrops has escalated. We reviewed published and unpublished data from field trials of Btcotton in the eastern and central Cotton Belt of the USA through 2015 to evaluate the effectiveness of Bt cotton (Bollgard, Bollgard II, WideStrike, WideStrike 3, and TwinLink). Btcotton reduced insecticide usage, reduced heliothine pest numbers and damage, and provided a yield benefit, but Bollgard II and WideStrike efficacy declined in the Midsouth over the period evaluated. In the Southeastern region, heliothine damage remained constant through 2015, but yield benefits declined from 2010 until 2015. Resistance of H. zea to several Bttoxins is the most plausible explanation for the observed changes in Btcotton efficacy. The introduction of new Bttoxins such as found in Widestrike 3 and Twinlink may preserve the benefits of Bt crops. However, while both Widestrike 3 and Twinlink had less damage than Widestrike, damage levels of both were similar to Bollgard II.
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    First transgenic trait for control of plant bugs and thrips in cotton
    Akbar, Waseem; Gowda, Anilkumar; Ahrens, Jeffrey E.; Stelzer, Jason W.; Brown, Robert S.; Bollman, Scott L.; Greenplate, John T.; Gore, Jeffrey; Catchot, Angus L.; Lorenz, Gus; Stewart, Scott D.; Kerns, David L.; Greene, Jeremy K.; Toews, Michael D.; Herbert, D. Ames Jr.; Reisig, Dominic D.; Sword, Gregory A.; Ellsworth, Peter C.; Godfrey, Larry D.; Clark, Thomas L. (Wiley, 2018-12-18)
    BACKGROUND: Plant bugs (Lygus spp.) and thrips (Thrips spp.) are two of the most economically important insect pest groups impacting cotton production in the USA today, but are not controlled by current transgenic cotton varieties. Thus, seed or foliar-applied chemical insecticides are typically required to protect cotton from these pest groups. Currently, these pests are resistant to several insecticides, resulting in fewer options for economically viable management. Previous publications documented the efficacy of transgenic cotton event MON 88702 against plant bugs and thrips in limited laboratory and field studies. Here, we report results from multi-location and multi-year field studies demonstrating efficacy provided by MON 88702 against various levels of these pests. RESULTS: MON 88702 provided a significant reduction in numbers of Lygus nymphs and subsequent yield advantage. MON 88702 also had fewer thrips and minimal injury. The level of control demonstrated by this transgenic trait was significantly better compared with its non-transgenic near-isoline, DP393, receiving insecticides at current commercial rates. CONCLUSION: The level of efficacy demonstrated here suggests that MON 88702, when incorporated into existing IPM programs, could become a valuable additional tool for management of Lygus and thrips in cotton agroecosystems experiencing challenges of resistance to existing chemical control strategies. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.