毒死蜱对蚯蚓生长和繁殖的影响

为探明毒死蜱对蚯蚓的影响,以赤子爱胜蚓Eisenia foetida为受试生物,以人工土壤为试验基质,采用接触暴露法,研究了毒死蜱对赤子爱胜蚓的急性毒性以及对蚯蚓生长和繁殖的影响。结果表明:在有效试验条件下,毒死蜱对蚯蚓的14 d-LC50值为88.75 mg/kg(每千克干土中含毒死蜱有效成分毫克数,其余同);暴露28 d后,10、25、50、80及100 mg/kg处理组蚯蚓的平均体重与对照相比依次下降了9.8%、15.7%、17.5%、23.9%和27.0%,体重下降与药剂处理浓度之间高度相关,且除10 mg/kg处理组外均与对照差异显著(P0.01,r=0.984);毒死蜱10、25、50、80及100 mg/kg处理组对蚯蚓繁殖的抑制率分别为32.26%、80.97%、89.03%、89.68%和97.42%,繁殖抑制率与药剂浓度之间存在一定的相关性(P0.01,r=0.788);毒死蜱影响蚯蚓生长和繁殖的28 d最低可观测效应浓度(LOEC)值为25 mg/kg。

Effects of chlorpyrifos on the growth and reproduction of earthworms, Eisenia foetida

In order to explore the effects of chlorpyrifos on earthworms, the acute toxicity of chlorpyrifos to Eisenia foetida and the effects of chlorpyrifos on the growth and reproduction of earthworms were investigated by exposing E.foetida to chlorpyrifos in artificial soil. The results indicated that the 14 d-LC₅₀ value of chlorpyrifos to E.foetida was 88.75 mg a.i./kg dry soil; After exposure to chlorpyrifos at 10, 25, 50, 80 and 100 mg a.i./kg dry soil for 28 d, the weight of E.foetida reduced significantly except the treatment of 10 mg a.i./kg dry soil; the body weight reducing rates were 9.8%, 15.7%, 17.5%, 23.9% and 27.0%, respectively, demonstrating a high correlation between the body weight reducing rate and the concentration(P<0.01, r=0.984). The reproduction inhibition rates of chlorpyrifos E.foetida at 10, 25, 50, 80 and 100 mg/kg dry soil were 32.26%, 80.97%, 89.03%, 89.68% and 97.42%, respectively, indicating a certain correlation(P >0.01, r=0.788) between the reproduction inhibition rate and the concentration. The 28 d-lowest observed effect concentration(LOEC) value of chlorpyrifos to the growth and reproduction of E.foetida was 25 mg/kg dry soil.