几种化学农药对烟蚜的毒性及其对异色瓢虫的安全性评价

Toxicity of Several Pesticides on Myzus persicae and Safety Evaluation to Predator Harmonia axyridis

采用喷雾法和药膜法测定了几种烟草推荐使用化学农药对烟蚜[Myzus persicae(Sulzer)]及其天敌异色瓢虫[Harmonia axyridis(Pallas)]成虫的毒性,并就各农药对异色瓢虫的安全性进行了评价。结果表明:3%啶虫脒,200 g/L吡虫啉,70%吡虫啉,5%吡虫啉和1.7%阿维·吡虫啉对烟蚜的LC50分别是7.89,12.91,178.91,33.34,2.60 mg/L,毒力大小依次为1.7%阿维·吡虫啉>3%啶虫脒>200 g/L吡虫啉>5%吡虫啉>70%吡虫啉。另外,3%啶虫脒对异色瓢虫成虫的毒力最高,LC50为8.61 mg/L,其次是1.7%阿维·吡虫啉、5%吡虫啉和200 g/L吡虫啉,70%吡虫啉对异色瓢虫的毒力最低,LC50为393.28 mg/L。结合益害比和安全系数,5%吡虫啉和200 g/L吡虫啉,70%吡虫啉对烟蚜和异色瓢虫的选择性较高,适宜在田间与异色瓢虫组合应用防控烟蚜。

The toxicity of several tobacco recommended pesticides on Myzus persicae （Sulzer） （ He- miptera： Aphididae） and its predatory natural enemy Harmonia axyridis （Pallas） adults was determined by means of spray and residual film, and the safety to the ladybirds was also evaluated. The result showed that the LC50 of 3% acetamiprid, 200 g/L imidacloprid, 70% imidacloprid, 5% imidacloprid and 1.7% avermectin · imidacloprid were 7.89, 12.91, 178.91, 33.34, 2. 60 mg/L, respectively. Therefore, the toxicity of these pesticides on M. persicae was 1.7 % avermectin · imidacloprid 〉 3 % acetamiprid 〉 200 g/L imidacloprid 〉 5% imidacloprid 〉 70% imidacloprid. In addition, the toxicity of 3% acetamiprid on Harmonia axyridis was the highest, and the LC50 was 8.61 mg/L, and then were 1.7% avermectin ·imidacloprid, 5% imidacloprid, 200 g/L imidacloprid and 70% imidacloprid, respectively, the toxicity of 70% imidacloprid was the lowest, which was 393.28 mg/L. According to toxicity ratio and safety coefficient, 5% imidacloprid, 200 g/L imidacloprid and 70% imidacloprid had high selection to M. persicae and H. axyridis, and they were suitable for using alternately with H. axyridis in controlling M. persicae.