六种杀虫剂对小地老虎的毒力及对土壤生物安全性评价

为筛选出高效安全的土壤处理杀虫剂,室内采用浸叶法比较了3种新杀虫剂与3种已登记的杀虫剂对小地老虎的毒力,同时用人工土壤法和密闭法分别测定了6种药剂对蚯蚓的急性毒性和对土壤呼吸强度的影响。结果显示,溴虫腈、茚虫威和甲维盐对小地老虎3龄幼虫的毒力明显高于3种已登记药剂毒死蜱、辛硫磷和高效氯氟氰菊酯;溴虫腈、茚虫威和甲维盐对蚯蚓的LC50分别为1320．80、1153．42和167．91mg／kg,均低于其它3种药剂,属于低毒级;供试杀虫剂中以溴虫腈对小地老虎和蚯蚓的毒力选择性最高,其毒力选择性比值（蚯蚓LC50／小地老虎LC50）为7115．23;6种药剂对土壤微生物均无危害性。

Toxicity of six insecticides to black cutworm Agrotis ypsilon (Rottemberg) and safety evaluation to oil organisms

Leaf-dip, artificial soil and direct absorption methods were used conducted to determine the laboratory toxicity of six insecticides to the black cutworm, Agrotis ypsilon (Rottemberg), the acute response to the earthworm, Eisenia foelida and the effects on respiration of soil microorganism, respectively. Results showed that the toxicity of chlorfenapyr, indoxacarb and emamectin benzoate was significantly higher than that of chlorpyrifos, phoxim and lambadacyhalothrin. The acute response to the earthworm results showed that the LC₅₀ of chlorfenapyr, indoxacarb and emamectin benzoate was 1 320.80, 1 153.42 and 167.91 mg/kg, which belonged to the inferior toxic category. The selective toxicity of chlorfenapyr was the highest among 6 insecticides tested, and its selective toxicity ratio reached 7 115.23. These pesticides all belong to the lower poisonous pesticide category on soil microbe.