Field efficacy of Bt cotton containing events DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 against lepidopteran pests and impact on the non-target arthropod community in Brazil

Abstract

The efficacy and non-target arthropod effects of transgenic DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 Bt cotton, expressing proteins Cry1Ac, Cry1F and Vip3Aa19, was examined through field trials in Brazil. Fifteen field efficacy experiments were conducted from 2014 through the 2020 growing season across six different states in Brazil to evaluate performance against key lepidopteran pests through artificial infestations of Chrysodeixis includens (Walker), Spodoptera frugiperda (J.E. Smith,1797), Spodoptera cosmioides (Walker, 1858) and Chloridea virescens (F., 1781), and natural infestations of Alabama argillacea (Hübner) and S. frugiperda. The impact of this Bt cotton technology on the non-target arthropod community in Brazilian cotton production systems was also assessed in a multi-site experiment. DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 cotton significantly reduced the feeding damage caused by S. frugiperda, S. cosmioides, C. includens, C. virescens and A. argillacea, causing high levels of mortality (greater than 99%) to all target lepidopteran pests evaluated during vegetative and/or reproductive stages of crop development. Non-target arthropod community-level analyses confirmed no unintended effects on the arthropod groups monitored. These results demonstrate the value of transgenic Bt cotton containing event DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 for consideration as part of an integrated approach for managing key lepidopteran pests in Brazilian cotton production systems.

Performance of cotton expressing Cry1Ac, Cry1F and Vip3Aa19 insecticidal proteins against Helicoverpa armigera, H. zea and their hybrid progeny, and evidence of reduced susceptibility of a field population of H. zea to Cry1 and Vip3Aa in Brazil

“…From pest management perspective, the cotton technology DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 beyond reasonable levels of mortality against H. armigera, also reduced the damage to squares. These results expand those previously reported by Marques et al [25], showing this same Bt cotton technology is highly effective against other lepidopteran pests of cotton. It is noteworthy that, the non-Vip3Aa containing products usually did not provide full control of S. frugiperda, and growers implemented multiple insecticide sprays that probably contributed to controlling Helicoverpa spp.…”

“…The second and third generations of Bt cotton met the concept of 'gene pyramiding' with the expression of two or more Bt proteins with high toxicity and distinct modes of action to the same pest species [23,24]. For example, the DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 event (commercially named Wide-Strike 1 3) is part of the third generation of Bt cotton cultivated in Brazil and expresses Cry1Ac, Cry1F and Vip3Aa19 insecticidal proteins [25].…”

Spatial scale of non-target effects of cotton insecticides

“…Plot size in non-target arthropod studies varies considerably [ 3 ]. For example, studies involving non-target species in arable crops used plots ranging from 11,800 to 16,900 m 2 in corn [ 37 ], and some recent studies used plots of 12 m 2 in soybeans [ 38 ], 21 m 2 in quinoa [ 39 ] and 170 and 500 m 2 in cotton [ 40 , 41 ]. In meta-analyses to examine the non-target impacts of transgenic Bt crops, Wolfenbarger et al [ 42 ] found no pattern in effect sizes between Bt and non-Bt crops over plot sizes ranging from 20–175,000 m 2 .…”

Effects on the yield and fiber quality components of Bt cotton inoculated with Azotobacter chroococcum under elevated CO2

“…Transgenic Bacillus thuringiensis cotton ( Bt cotton), Gossypium spp , hybrids expressing the Cry insect-resistant gene were adopted worldwide to control Lepidoptera pests ( Luiz et al, 2021 ; Prasad, Rao & Naik, 2013 ), and were impressible to environmental variations, environmental stresses can cause changes on their growth and yield ( Wang et al, 2015 ). The safe production of Bt cotton has attracted wide attention to their growth under climate change.…”