Bargar Timothy A, Hladik Michelle L, Daniels Jaret C
Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL, USA.
California Water Science Center, U.S. Geological Survey, Sacramento, CA, USA.
PeerJ. 2020 Mar 10;8:e8669. doi: 10.7717/peerj.8669. eCollection 2020.
Recent concern for the adverse effects from neonicotinoid insecticides has centered on risk for insect pollinators in general and bees specifically. However, natural resource managers are also concerned about the risk of neonicotinoids to conservation efforts for the monarch butterfly () and need additional data to help estimate risk for wild monarch butterflies exposed to those insecticides. In the present study, monarch butterfly larvae were exposed in the laboratory to clothianidin via contaminated milkweed plants from hatch until pupation, and the effects upon larval survival, larval growth, pupation success, and adult size were measured. Soils dosed with a granular insecticide product led to mean clothianidin concentrations of 10.8-2,193 ng/g in milkweed leaves and 5.8-58.0 ng/g in larvae. Treatment of soils also led to clothianidin concentrations of 2.6-5.1 ng/g in adult butterflies indicating potential for transfer of systemic insecticides from the soil through plants and larvae to adult butterflies. Estimated LCs for total mortality (combined mortality of larvae and pupae) and EC50 for larval growth were variable but higher than the majority of concentrations reported in the literature for clothianidin contamination of leaves.
近期，新烟碱类杀虫剂的不良影响主要集中在对昆虫传粉者的风险上，尤其是蜜蜂。然而，自然资源管理者也担心新烟碱类物质对帝王蝶保护工作的风险，并且需要更多数据来帮助评估野生帝王蝶接触这些杀虫剂的风险。在本研究中，帝王蝶幼虫在实验室中从孵化到化蛹期间通过受污染的马利筋植物接触噻虫胺，并测量其对幼虫存活、幼虫生长、化蛹成功率和成虫大小的影响。用颗粒状杀虫剂产品处理土壤后，马利筋叶片中的噻虫胺平均浓度为10.8 - 2193纳克/克，幼虫中的浓度为5.8 - 58.0纳克/克。土壤处理还导致成年蝴蝶体内的噻虫胺浓度为2.6 - 5.1纳克/克，这表明内吸性杀虫剂有可能从土壤通过植物和幼虫转移到成年蝴蝶体内。总死亡率（幼虫和蛹的综合死亡率）的估计致死浓度（LC）和幼虫生长的半数有效浓度（EC50）各不相同，但高于文献报道的大多数噻虫胺叶片污染浓度。
