Risk Assessment Laboratory for Bee Products Quality and Safety of Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, PR China; College of Sciences, China Agricultural University, Beijing 100093, PR China.
College of Life Sciences, Peking University, 5 Yiheyuan Road, Beijing 100871, PR China.
Ecotoxicol Environ Saf. 2018 Feb;148:352-358. doi: 10.1016/j.ecoenv.2017.10.042. Epub 2017 Nov 6.
Cycloxaprid (CYC) and guadipyr (GUA) are two new and promising neonicotinoid insecticides whose effects on Daphnia magna are as yet unknown. In this study, the acute toxicities of CYC and GUA to D. magna, including immobilization and embryo-hatching inhibition, and their effects on antioxidant enzymes and related gene expression were determined after a 48-h exposure. Imidacloprid (IMI) was evaluated at the same time as a reference agent. The 48-h EC values of IMI, GUA, and CYC for neonate immobilization were 13.0-16.5mg/L and for embryo hatching were 11.3-16.2mg/L. The specific activity of the enzymes superoxide dismutase (SOD) and catalase (CAT) were interfered by IMI, but not by GUA and CYC, while the activity of acetylcholinesterase (AChE) was significantly increased by IMI, but inhibited by GUA and CYC. The relative expressions of the Sod-Cu/Zn, Sod-Mn, Cat, and Ache genes were usually inhibited by IMI, GUA, and CYC, except for Cat by CYC, Ache by GUA, and Sods by IMI. For vitellogenin genes with a SOD-like domain (Vtg1/2-sod), relative expression was increased by IMI and inhibited by GUA and CYC, indicating that IMI, GUA, and CYC have potential toxicity toward reproduction. CYC and GUA are highly active against IMI-resistant pests, and considering the similar toxicity of IMI to D. magna, CYC and GUA are suitable for use in future integrated pest management systems.
环吡丙醚（CYC）和噻虫啉（GUA）是两种新型且有前景的新烟碱类杀虫剂，但其对大型溞（Daphnia magna）的影响尚不清楚。在这项研究中，通过 48 小时暴露，测定了 CYC 和 GUA 对大型溞的急性毒性，包括对其的麻醉和胚胎孵化抑制作用，以及它们对抗氧化酶和相关基因表达的影响。同时，评估了吡虫啉（IMI）作为参考药剂的效果。IMI、GUA 和 CYC 对幼体麻醉的 48 小时 EC 值分别为 13.0-16.5mg/L 和 11.3-16.2mg/L。酶超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的比活力受到 IMI 的干扰，但不受 GUA 和 CYC 的干扰，而乙酰胆碱酯酶（AChE）的活性则显著被 IMI 增强，却被 GUA 和 CYC 抑制。Sod-Cu/Zn、Sod-Mn、Cat 和 Ache 基因的相对表达通常受到 IMI、GUA 和 CYC 的抑制，但 CYC 对 Cat、GUA 对 Ache 以及 IMI 对 Sods 除外。对于具有 SOD 样结构域的卵黄蛋白原基因（Vtg1/2-sod），其相对表达被 IMI 增强，而被 GUA 和 CYC 抑制，表明 IMI、GUA 和 CYC 对生殖具有潜在毒性。CYC 和 GUA 对 IMI 抗性害虫具有高度活性，并且考虑到 IMI 对大型溞的毒性相似，CYC 和 GUA 适合用于未来的综合虫害管理系统。
