Acuteandchronictoxicitiesofspirotetramatto<italic>Daphniamagna</italic>

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.