螺虫乙酯对大型溞的急性和慢性毒性效应

为评价新型季酮酸衍生物类杀虫剂螺虫乙酯(spirotetramat)对水生生物的生态危害，以大型溞Daphnia magna为研究对象，将其暴露于不同质量浓度的螺虫乙酯中，通过急性毒性试验、慢性毒性试验和子代染毒及恢复试验，研究螺虫乙酯对大型溞的急性和21 d慢性毒性效应。急性毒性试验结果表明，螺虫乙酯对大型溞的48 h-EC₅₀值为46.55 mg/L。慢性毒性试验结果表明，经不同浓度螺虫乙酯暴露21 d后，4.7 mg/L浓度组在初次产溞数、母溞产溞总数和母溞产胎数上较对照都有显著减少，并显著延后了初次产溞的时间。经螺虫乙酯暴露后的F₀代大型溞所产后代(F₁代)对螺虫乙酯的耐药性降低，同时对F₁代染毒组的初次产溞时间、初次产溞数和产胎数均有显著影响，但仅对F₁代恢复组的体长有显著影响。综上所述，螺虫乙酯对大型溞具有一定的生殖毒性，并在一定程度上对大型溞的生长和繁殖能力具有抑制效应。

Acute and chronic toxicities of spirotetramat to Daphnia magna

In order to evaluate the aquatic toxicity of the new tetramic acid derivative spirotetramat, the acute-chronic toxicity, offspring contamination and recovery test of Daphnia magna under different concentrations of spirotetramat were conducted. The acute toxicity results indicated that spirotetramat had low toxicity against D. magna, the 48 h-EC₅₀ value was 46.55 mg/L. The results of chronic test showed that, 21 days after exposure to spirotetramat, the first reproduction number, the number of total offspring per female and the number of brood per female of D. magna were significantly reduced. The first reproduction time was also evidently delayed at the concentration of 4.7 mg/L spirotetramat. The offspring of F₀ generation D. magna (named F₁ generation D. magna) was more sensitive to spirotetramat than the control. And the first reproduction time, the first reproduction number and the number of brood were significantly influenced, and only the body length of F₁ recovery group was significantly affected. In conclusion, spirotetramat had severe reproductive toxicity to D. magna, and had inhibiting effects on its growth and reproduction.