As part of an ongoing longitudinal study in North and South Carolina, this study reports the recovery of Helicoverpa zea (Boddie) pupae in field trials with genetically engineered corn, Zea mays L., hybrids that produce insecticidal toxins from Bacillus thuringiensis (Bt) in 2017-2019. In total, 10,400 corn ears were collected, which led to 3,927 H. zea pupae (2,215 in South Carolina and 1,712 in North Carolina). Late-planted corn led to a 3.39-fold increase in recovery of pupae compared to early-planted corn. Bt corn expressing Cry1F + Cry1Ab and Cry1A.105 + Cry2Ab2 had 1.67-fold and 2.51-fold fewer pupae than non-Bt near-isolines, respectively. Only six pupae were recovered from the hybrid expressing Cry1F + Cry1Ab + Vip3Aa20. Averaged across trials, Bt corn expressing either Cry1A.105 + Cry2Ab2 or Cry1F + Cry1Ab significantly reduced pupal weight compared to non-Bt near-isolines in North and South Carolina. Combining our data with a previous study at the same locations (Bilbo et al. 2018), reduction in pupal weight between Bt and non-Bt near-isolines significantly declined from 2014 to 2019 for Cry1Ab + Cry1F in North and South Carolina. This decline in levels of a sublethal effect of Bt corn expressing Cry1Ab + Cry1F on H. zea at both locations is likely correlated with resistance development.

中文翻译：

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Bt 玉米对玉米穗虫（鳞翅目：夜蛾科）的亚致死作用下降与抗性水平增加有关

作为在北卡罗来纳州和南卡罗来纳州正在进行的纵向研究的一部分，本研究报告了在田间试验中使用转基因玉米 Zea mays L. 对 Helicoverpa zea (Boddie) 蛹的恢复，Zea mays L. 杂交种可从 苏云金芽孢杆菌 (Bt) 产生杀虫毒素。 2017-2019 年。总共收集了 10,400 个玉米穗，产生了 3,927 只玉米穗蛹（南卡罗来纳州 2,215 只，北卡罗来纳州 1,712 只）。与早播玉米相比，晚播玉米使蛹的恢复率提高了 3.39 倍。表达 Cry1F + Cry1Ab 和 Cry1A.105 + Cry2Ab2 的 Bt 玉米的蛹数分别比非 Bt 近等系的蛹少 1.67 倍和 2.51 倍。从表达 Cry1F + Cry1Ab + Vip3Aa20 的杂交体中仅回收了 6 只蛹。跨试验平均，Bt 玉米表达任一 Cry1A。105 + Cry2Ab2 或 Cry1F + Cry1Ab 与北卡罗来纳州和南卡罗来纳州的非 Bt 近等系相比显着降低了蛹的重量。将我们的数据与之前在同一地点进行的研究（Bilbo 等人，2018 年）相结合，从 2014 年到 2019 年，北卡罗来纳州和南卡罗来纳州的 Cry1Ab + Cry1F 的 Bt 和非 Bt 近等值线之间的蛹重量减少显着下降。表达 Cry1Ab + Cry1F 的 Bt 玉米对两个位置的 H. zea 的亚致死效应水平的下降可能与抗性发展相关。