云南通海小菜蛾种群抗药性监测及田间药效评价

Resistance monitoring of diamondback moth and field control efficacy of pesticides against the pest in Tonghai,Yunnan Province

为掌握云南蔬菜主产区通海县小菜蛾种群对常用杀虫剂的敏感性及其田间防治效果,采用浸叶法和田间小区试验对常用杀虫剂进行室内毒力测定和田间药效试验。结果表明:通海县小菜蛾种群对丁醚脲和Bt的敏感性最高,仍处于敏感水平,对茚虫威属低抗水平,对虫螨腈和多杀菌素的抗性倍数分别为24.28和31.68倍,属中抗水平,对氯虫苯甲酰胺抗性倍数为44.62倍,到高抗水平,对阿维菌素的敏感性最差,抗性倍数829.90倍,达极高抗水平。抗性水平和田间药效呈一定相关性,氯虫苯甲酰胺和阿维菌素药后7d对小菜蛾的防治效果均低于50%,茚虫威、多杀菌素和丁醚脲的田间防效较好。通海县小菜蛾可选择的防治药剂包括茚虫威、多杀菌素和丁醚脲,注意不同药剂之间的轮换和交替使用。

To understand the current status of insecticide resistance in diamondback moth （DBM）, Plutella xylos- tella （L.） and the control efficacy of some common insecticides to DBM in Tonghai County, Yunnan Province, the indoor leaf-dipping bioassay and field trial were conducted, respectively. The results showed that the suscepti- bility of the Tonghai DBM to diafenthiuron and Bt were the highest, and exhibited sensitive levels. The resistance level was low to indoxacarb. The resistance ratios to chlorfenapyr and spinosad were 24.28 and 31.68 fold, re- spectively, which showed a middle resistance level. As to chlorantraniliprole, the resistance ratio was 44.62 fold with a high resistance level. The susceptibility to abamectin was the lowest and the resistance ratio was high to 829.90-fold. There was some correlation between the resistance ratio and the field control efficacy. The control efficacy of chlorantraniliprole and abamectin to the DBM was below 50% seven days after treatment. Indoxacarb, spinosad and diafenthiuron provided good control efficacy to the DBM, which can be selected for the DBM control in Tonghai with rational rotation and alternative using strategy.