几种低毒农药对韭菜迟眼蕈蚊幼虫的毒力测定

Toxicity Determination of Several Low Toxicity Insecticides to Larval of Bradysia odoriphaga

为缓解长期使用高毒农药带来的韭菜迟眼蕈蚊(Bradysia odoriphaga Yang et Zhang)抗药性的产生以及韭菜农药残留超标等问题,选取了6种低毒农药对韭菜迟眼蕈蚊3龄幼虫进行室内毒力测定。结果表明:处理96 h,不同药剂的毒力大小为:辛硫磷>毒死蜱>多拉菌素>七氟菊酯>氟啶脲>氟铃脲>米尔贝霉素>天维菌素。辛硫磷和毒死蜱比其它6种药剂致死速度快,浓度为20 mg/L时,两者的LT_(50)分别为24.185h和39.092 h;药剂浓度为100 mg/L时,其它6种药剂的LT_(50)顺序为:七氟菊酯>多拉菌素>氟啶脲>氟铃脲>米尔贝霉素>天维菌素。

To relieve the problems of insecticide resistance of Bradysia odoriphaga and excessive insecti- cide residues of Chinese chive because of high toxicity insecticides used for a long time, the toxicities of 6 kinds of low toxicity insecticides to 3 - instar larvae of Bradysia odoriphaga were evaluated in laboratory. The results showed that after treated for 96 hours, the order of insecticidal toxicity was as follows ： phoxim 〉 chlor- pyrifos 〉 doramectin 〉 tefluthrin 〉 chlorfluazuron 〉 hexaflumuron 〉 milbemycin 〉 Tianwei - streptozotocin. The killing speed of phoxim and chlorpyrifos were more quick than the other 6 insecticides. When the concentra- tion was 20 rag/L, the LTso of phoxim and chlorpyrifos was 24. 185 h and 39. 092 h respectively. When the concentration was 100 mg/L, the LT50 of the other 6 insecticides was as follows： tefluthrin 〉 doramectin 〉 chlorfluazuron 〉 hexaflumuron 〉 milbemycin 〉 Tianwei - streptozotocin.