Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, Brazil.
Departamento de Manejo e Conservação de Ecossistemas Naturais e Agrários, Universidade Federal de Viçosa - Campus Florestal, Florestal, Brazil.
Pest Manag Sci. 2021 Jul;77(7):3088-3098. doi: 10.1002/ps.6388. Epub 2021 Apr 14.
A high dose/refuge combination is the main tactic recommended for mitigating resistance selection of target herbivore species in crops expressing insecticidal proteins of the bacterium Bacillus thuringiensis (i.e. Bt proteins). The tactic consists of the simultaneous use of Bt crops expressing high levels of the Bt protein associated with neighboring areas of refuge of the same non-Bt crop species. Nonetheless, the approach faces controversy regarding its effectiveness and scale of adoption, at least in some regions. One concern focuses on its potential impact on the arthropod community, including its short-term and spatially dependent impact considering the likely biota spillover effect between Bt and non-Bt neighboring areas. Thus, the eventual spillover of Bt maize targeted and non-targeted arthropods was surveyed along transects extending from the refuge border to the center of the Bt maize area.
Arthropods were collected throughout the maize vegetative and reproductive stages. A total of 85 arthropod species were collected, but their richness and abundance did not vary with distance from the refuge. By contrast, cultivation season played a significant role in distinguishing the arthropod communities. Refuge distance from the sampling point within Bt-fields did not significantly affect the food web metrics, unlike season, which affected the number of nodes integrating each food web. Winter maize cultivation exhibited higher arthropod diversity and combined values of species numeric abundance and biomass at each trophic level.
No arthropod spillover was evident between the refuge edge and Bt maize, adding further controversy to the tactic currently subjected to lower usage in the region with a disputed cost-benefit relationship, because not even the target and its interdependent species were affected. © 2021 Society of Chemical Industry.
在表达苏云金芽孢杆菌（即 Bt 蛋白）杀虫蛋白的作物中，高剂量/避难所组合是减轻目标食草动物物种抗药性选择的主要策略。该策略包括同时使用表达与同一非 Bt 作物物种避难所相邻地区高浓度 Bt 蛋白的 Bt 作物。尽管如此，该方法在一些地区至少在其有效性和采用规模方面存在争议。人们关注的一个问题是它对节肢动物群落的潜在影响，包括考虑到 Bt 和非 Bt 相邻地区之间可能的生物群溢出效应，其短期和空间依赖性影响。因此，沿着从避难所边界延伸到 Bt 玉米区域中心的样带调查了最终溢出的 Bt 玉米靶标和非靶标节肢动物。
在玉米营养生长和生殖生长阶段都采集了节肢动物。共采集到 85 种节肢动物，但它们的丰富度和丰度与距避难所的距离无关。相比之下，种植季节在区分节肢动物群落方面起着重要作用。Bt 田内从采样点到避难所的距离对食物网指标没有显著影响，而季节则影响整合每个食物网的节点数量。冬玉米种植表现出更高的节肢动物多样性和每个营养水平的物种数量丰度和生物量的综合值。
在避难所边缘和 Bt 玉米之间没有明显的节肢动物溢出，这使得该策略在该地区的使用进一步受到争议，因为即使是靶标及其相互依存的物种也没有受到影响，而该地区对该策略的成本效益关系存在争议。© 2021 化学工业协会。
