Conservation of North America's eastern monarch butterfly (Danaus plexippus) population would require establishment of milkweed (Asclepias spp.) and nectar plants in the agricultural landscapes of the north central United States. A variety of seed-treatment and foliar insecticides are used to manage early- and late-season pests in these landscapes. Thus, there is a need to assess risks of these insecticides to monarch butterfly life stages to inform habitat conservation practices. Chronic and acute dietary toxicity studies were undertaken with larvae and adults, and acute topical bioassays were conducted with eggs, pupae, and adults using 6 representative insecticides: beta-cyfluthrin (pyrethroid), chlorantraniliprole (anthranilic diamide), chlorpyrifos (organophosphate), imidacloprid, clothianidin, and thiamethoxam (neonicotinoids). Chronic dietary median lethal concentration values for monarch larvae ranged from 1.6 × 10^–3 (chlorantraniliprole) to 5.3 (chlorpyrifos) μg/g milkweed leaf, with the neonicotinoids producing high rates of arrested pupal ecdysis. Chlorantraniliprole and beta-cyfluthrin were generally the most toxic insecticides to all life stages, and thiamethoxam and chlorpyrifos were generally the least toxic. The toxicity results were compared to insecticide exposure estimates derived from a spray drift model and/or milkweed residue data reported in the literature. Aerial applications of foliar insecticides are expected to cause high downwind mortality in larvae and eggs, with lower mortality predicted for adults and pupae. Neonicotinoid seed treatments are expected to cause little to no downslope mortality and/or sublethal effects in larvae and adults. Given the vagile behavior of nonmigratory monarchs, considering these results within a landscape-scale context suggests that adult recruitment will not be negatively impacted if new habitat is established in close proximity of maize and soybean fields in the agricultural landscapes of the north central United States. Environ Toxicol Chem 2021;40:1761–1777. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

中文翻译：

---

叶面和种子处理杀虫剂对帝王蝶 (Danaus plexippus) 的生命阶段风险

北美东部帝王蝶 ( Danaus plexippus ) 种群的保护需要建立乳草 ( Asclepiasspp.) 和美国中北部农业景观中的花蜜植物。各种种子处理和叶面杀虫剂用于管理这些景观中的早季和晚季害虫。因此，有必要评估这些杀虫剂对帝王蝶生命阶段的风险，为栖息地保护实践提供信息。对幼虫和成虫进行了慢性和急性膳食毒性研究，并使用 6 种代表性杀虫剂对卵、蛹和成虫进行了急性局部生物测定：β-氟氯氰菊酯（拟除虫菊酯）、氯虫苯甲酰胺（邻氨基苯甲酸二胺）、毒死蜱（有机磷酸酯）、吡虫啉、噻虫胺和噻虫嗪（新烟碱类）。君主幼虫的慢性饮食中位致死浓度值范围为 1.6 × 10 ^–3（氯虫苯甲酰胺）至 5.3（毒死蜱）μg/g 马利筋叶，新烟碱类产生高速率的蛹蜕皮停滞。氯虫苯甲酰胺和 β-氟氯氰菊酯通常是对所有生命阶段毒性最大的杀虫剂，噻虫嗪和毒死蜱通常毒性最小。毒性结果与来自喷雾漂移模型和/或文献中报道的马利筋残留数据的杀虫剂暴露估计值进行了比较。叶面杀虫剂的空中应用预计会导致幼虫和卵的高顺风死亡率，预计成虫和蛹的死亡率较低。预计新烟碱类种子处理对幼虫和成虫几乎不会造成下坡死亡率和/或亚致死效应。鉴于非迁徙君主的易变行为，环境毒物化学2021；40:1761–1777。© 2021 作者。Wiley Periodicals LLC 代表 SETAC 出版的Environmental Toxicology and Chemistry 。