农药乐果对昭觉林蛙蝌蚪的急性毒性研究

Studies on the Acute Toxicity of Dimethoate to Tadpole of Rana chaochiaoensis

用水生生物急性毒性试验方法,研究乐果对昭觉林蛙(Rana chaochiaoensis)蝌蚪的急性毒性影响。结果表明:在水温(20.5±0.5)℃条件下,乐果对昭觉林蛙蝌蚪24 h,48 h,72 h,96 h的半致死浓度(LC50)分别为:76.97mg/L,67.85 mg/L,56.61 mg/L,52,80 mg/L,并呈现出线性关系,安全浓度(SC)为5.28 mg/L。由此得出,乐果对昭觉林蛙蝌蚪属于低毒性农药,当乐果残留量超过安全浓度时,将会影响昭觉林蛙蝌蚪的正常生长发育。

The experiment of acute toxicity of dimethoate on Rana chaochiaoensis tadpole was done by the acute toxicity method of aquatic biology. The results showed that the LC50 of the Dimethoate of 24, 48,72 and 96 h to Rana chaochiaoensis tadpole were 76. 97 mg/L, 67.85 mg/L, 56. 61 mg/L and 52. 80 mg/L respectively. The results presented linear characters. The corresponding SC was 5.28 mg/L. It appears that the dimethoate is low toxicity to Rana chaochiaoensis tadpole, and if the remanet of dimethoate exceeds safe concentration, the normal growth of Rana chaochiaoensis tadpole will be affected.