为探究敌敌畏、乐果对不同龄期柞蚕幼虫的急性毒性,采用食下毒叶法喂食不同龄期的柞蚕幼虫,连续观察96 h,分时间段测定敌敌畏、乐果对柞蚕幼虫的半数致死浓度(LC_(50));通过熏蒸毒性试验,连续观察72 h,记录对不同龄期柞蚕幼虫的熏蒸毒性...为探究敌敌畏、乐果对不同龄期柞蚕幼虫的急性毒性,采用食下毒叶法喂食不同龄期的柞蚕幼虫,连续观察96 h,分时间段测定敌敌畏、乐果对柞蚕幼虫的半数致死浓度(LC_(50));通过熏蒸毒性试验,连续观察72 h,记录对不同龄期柞蚕幼虫的熏蒸毒性,利用SPSS软件,建立模型方程,计算出敌敌畏、乐果对不同龄期柞蚕幼虫的LC_(50)及置信区间。结果显示,2种农药毒性相比,敌敌畏高于乐果。敌敌畏对5龄柞蚕幼虫的24 h LC_(50)最高达到277.159 mg/L,对1龄柞蚕幼虫的96 h LC_(50)最低为0.161 mg/L,对1、2龄柞蚕幼虫的毒性为剧毒,对其它龄期柞蚕幼虫的毒性为高毒;乐果对5龄柞蚕幼虫的24 h LC_(50)最高达到391 858.000 mg/L,对1龄柞蚕幼虫的96 h LC_(50)最低为0.652 mg/L,对1龄柞蚕幼虫的毒性为剧毒,对其它龄期柞蚕幼虫的毒性为中毒或低毒。敌敌畏对柞蚕幼虫的熏蒸毒性为高风险,乐果对柞蚕幼虫也有一定的熏蒸毒性。展开更多
Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of...Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of these two pesticides was measured as median lethal concentration values(LC 50 ) of earth worms.Tests of three different exposure systems were performed:the comact filter paper bioassay,the immersion bioassay and the artificial soil bioassay.The results indicated that the two new type pesticides showed vaious toxic effects through different exposure paths .The LC 50 of 1 (6 chloro 3 pyridinymethyl) N nitromidazolidin 2 ylideneamine was 0.034 ug·cm 2 for 48hr filter paper test,0.77mg·ml -1 for 48hr inmersion test and 2.3mg·kg -1 for 14d artiflcial soil test,respectively; while the 2′ benzoy 1′tert butylbenzoylhydrazine was>480 μg·cm -2 for 48hr filter paper test. 2655 mg·ml -1 for 48hr immersion test,and>10000mg·kg -1 for 14d artificial soil test,respectively.These outcome led to a conelusion that 1 (6 chloro 3 pyridinylmethyl) N nitromidazolidin 2 ylideneamine was far more toxic than 2′ benzoyl 1′tert butylbenzoylhydrazine with regard to acute toxicity to earthworm.However,the comprehensive assessment of the influence of both the two pesticides to soil ecosystem could not be made only by acute toxic tests because we were not aware of the mechanism acted on organisms.展开更多
文摘为探究敌敌畏、乐果对不同龄期柞蚕幼虫的急性毒性,采用食下毒叶法喂食不同龄期的柞蚕幼虫,连续观察96 h,分时间段测定敌敌畏、乐果对柞蚕幼虫的半数致死浓度(LC_(50));通过熏蒸毒性试验,连续观察72 h,记录对不同龄期柞蚕幼虫的熏蒸毒性,利用SPSS软件,建立模型方程,计算出敌敌畏、乐果对不同龄期柞蚕幼虫的LC_(50)及置信区间。结果显示,2种农药毒性相比,敌敌畏高于乐果。敌敌畏对5龄柞蚕幼虫的24 h LC_(50)最高达到277.159 mg/L,对1龄柞蚕幼虫的96 h LC_(50)最低为0.161 mg/L,对1、2龄柞蚕幼虫的毒性为剧毒,对其它龄期柞蚕幼虫的毒性为高毒;乐果对5龄柞蚕幼虫的24 h LC_(50)最高达到391 858.000 mg/L,对1龄柞蚕幼虫的96 h LC_(50)最低为0.652 mg/L,对1龄柞蚕幼虫的毒性为剧毒,对其它龄期柞蚕幼虫的毒性为中毒或低毒。敌敌畏对柞蚕幼虫的熏蒸毒性为高风险,乐果对柞蚕幼虫也有一定的熏蒸毒性。
文摘Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of these two pesticides was measured as median lethal concentration values(LC 50 ) of earth worms.Tests of three different exposure systems were performed:the comact filter paper bioassay,the immersion bioassay and the artificial soil bioassay.The results indicated that the two new type pesticides showed vaious toxic effects through different exposure paths .The LC 50 of 1 (6 chloro 3 pyridinymethyl) N nitromidazolidin 2 ylideneamine was 0.034 ug·cm 2 for 48hr filter paper test,0.77mg·ml -1 for 48hr inmersion test and 2.3mg·kg -1 for 14d artiflcial soil test,respectively; while the 2′ benzoy 1′tert butylbenzoylhydrazine was>480 μg·cm -2 for 48hr filter paper test. 2655 mg·ml -1 for 48hr immersion test,and>10000mg·kg -1 for 14d artificial soil test,respectively.These outcome led to a conelusion that 1 (6 chloro 3 pyridinylmethyl) N nitromidazolidin 2 ylideneamine was far more toxic than 2′ benzoyl 1′tert butylbenzoylhydrazine with regard to acute toxicity to earthworm.However,the comprehensive assessment of the influence of both the two pesticides to soil ecosystem could not be made only by acute toxic tests because we were not aware of the mechanism acted on organisms.