七种药物对微小牛蜱的半数致死浓度测定

用浸渍法测定了楝素、三氟氯氰菊酯、苦皮藤、高效氯氰菊酯、溴氰菊酯、哒嗪酮、螨净 7种药物对未吸血的微小牛蜱 (Boophilusmicroplus)幼蜱、若蜱、成蜱及其饱血雌蜱的半数致死浓度(LC50 )。结果显示 ,所用药物中半数致死浓度最低的 3种药物是楝素、三氟氯氰菊酯、苦皮藤。植物性杀虫剂楝素对未吸血微小牛蜱的幼蜱、若蜱、成蜱及饱血雌蜱的半数致死浓度分别为3.0 1～ 3.13、4 .37～ 4 .77、11.18～ 11.36、2 75 .5 0～ 2 76 .5 0mg/L ;植物性杀虫剂苦皮藤对未吸血微小牛蜱的幼蜱、若蜱、成蜱及饱血雌蜱的半数致死浓度分别为 4 .2 2～ 4 .4 2、10 .30～ 10 .5 0、82 .5 0～82 .70、6 35 .30～ 6 36 .70mg/L ;人工合成的除虫菊酯类的三氟氯氰菊酯对未吸血微小牛蜱的幼蜱、若蜱、成蜱及饱血雌蜱的半数致死浓度分别为 3.4 2～ 3.4 4、7.10～ 9.0 6、4 2 .30～ 4 2 .5 0、5 45 .5 0～5 46 .70mg/L。

Determination of median lethal concentration of seven kinds of medicines against Boophilus microplus

The LC_(50)'s of Melia toosendan, cyalothrin, celangulins, cypermethrin, deltamethrin, (pyridaziones) and diazinon against larvae, nymphs, undistended adults and engorged adult females were determined by the standard immersion method respectively. The results showed that the LC_(50)'s of Melia toosendan, cyalothrin and celangulins were lower than that of other medicines mentioned above. The LC_(50) scopes of plant insecticide Melia toosendan against the unengorged larvae, nymphs and adults and the (engorged) adult femals of B.microplus were 3.01-3.13,4.37-4.77,11.18-11.36 and 275.50-276.50 (mg/L) respectively, the LC_(50) scopes of celangulins were 4.22-4.42, 10.30-10.50,82.50-82.70 and 635.30-636.70 mg/L correspondingly, and the LC_(50) scopes of cyalothrin made artificially were 3.42-(3.44),7.10-9.06,42.30-42.50 and 545.50-546.70 mg/L correspondingly.