Establishing habitat in agricultural landscapes of the north central United States is critical to reversing the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Insecticide use could create population sinks and threaten recovery. Discouraging habitat establishment within a 38-m zone around crop fields is a suggested risk mitigation measure. In Story County, Iowa, United States, this mitigation would discourage habitat establishment in 84% of roadsides and 38% of noncrop land. It is unclear if the conservation benefits from establishing habitat close to crop fields outweigh suppression of population growth owing to insecticide exposure. Consequently, monarch conservation plans require spatially and temporally explicit landscape-scale assessments. Using an agent-based model that incorporates female monarch movement and egg laying, the number and location of eggs laid in Story County were simulated for four habitat scenarios: current condition, maximum new establishment, moderate establishment, and moderate establishment only outside a 38-m no-plant zone around crop fields. A demographic model incorporated mortality from natural causes and insecticide exposure to simulate adult monarch production over 10 years. Assuming no insecticide exposure, simulated adult production increased 24.7% and 9.3%, respectively, with maximum and moderate habitat establishment and no planting restrictions. A 3.5% increase was simulated assuming moderate habitat establishment with a 38-m planting restriction. Impacts on adult production were simulated for six representative insecticides registered for soybean aphid (Aphis glycines) management. Depending on the frequency of insecticide applications over a 10-year period, simulated production increased 8.2%–9.3%, assuming moderate habitat establishment with no planting restrictions. Results suggest that the benefits of establishing habitat close to crop fields outweigh the adverse effects of insecticide spray drift; that is, metapopulation extirpation is not a concern for monarchs. These findings are only applicable to species that move at spatial scales greater than the scale of potential spray-drift impacts. Integr Environ Assess Manag 2021;17:989–1002. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

中文翻译：

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在美国中北部玉米和大豆田附近建立帝王蝶 (Danaus plexippus) 繁殖栖息地的保护风险和收益：叶面杀虫剂对非迁徙帝王蝶种群影响的景观尺度分析

在美国中北部的农业景观中建立栖息地对于扭转北​​美东部帝王蝶（Danaus plexippus）的衰退至关重要) 人口。杀虫剂的使用可能会造成人口下降并威胁复苏。建议在农田周围 38 米的区域内建立栖息地，这是一项建议的风险缓解措施。在美国爱荷华州的斯托里县，这种缓解措施将阻碍 84% 的路边和 38% 的非农用土地的栖息地建立。目前尚不清楚在农田附近建立栖息地对保护的好处是否超过了杀虫剂暴露对人口增长的抑制。因此，君主保护计划需要在空间和时间上进行明确的景观尺度评估。使用结合了雌性君主运动和产卵的基于代理的模型，针对四种栖息地场景模拟了故事县产卵的数量和位置：当前状况、最大新建立、中等建立、仅在农田周围 38 米的无植物区外进行适度种植。人口统计模型结合了自然原因造成的死亡率和杀虫剂暴露，以模拟 10 年的成年帝王蝶生产。假设没有接触杀虫剂，模拟成虫产量分别增加了 24.7% 和 9.3%，最大和中等栖息地建立，没有种植限制。假设适度的栖息地建立和 38 米的种植限制，模拟了 3.5% 的增长。针对大豆蚜虫登记的六种代表性杀虫剂对成虫产量的影响进行了模拟（假设没有杀虫剂暴露，模拟成虫产量分别增加了 24.7% 和 9.3%，最大和中等栖息地建立，没有种植限制。假设适度的栖息地建立和 38 米的种植限制，模拟了 3.5% 的增长。针对大豆蚜虫登记的六种代表性杀虫剂对成虫产量的影响进行了模拟（假设没有杀虫剂暴露，模拟成虫产量分别增加了 24.7% 和 9.3%，最大和中等栖息地建立，没有种植限制。假设适度的栖息地建立和 38 米的种植限制，模拟了 3.5% 的增长。针对大豆蚜虫登记的六种代表性杀虫剂对成虫产量的影响进行了模拟（蚜虫甘氨酸）管理。根据 10 年期间杀虫剂应用的频率，假设栖息地建立适度且没有种植限制，模拟产量增加了 8.2%–9.3%。结果表明，在靠近农田的地方建立栖息地的好处超过了杀虫剂喷雾漂移的不利影响；也就是说，元种群灭绝不是君主关心的问题。这些发现仅适用于空间尺度大于潜在喷雾漂移影响尺度的物种。Integr Environ Assess Manag 2021；17：989-1002。© 2021 作者。综合环境评估和管理由 Wiley Periodicals LLC 代表环境毒理学与化学学会 (SETAC) 发布。