柑橘全爪螨田间种群敏感性测定及三种主要解毒酶活性比较

为明确重庆地区柑橘全爪螨Panonychus citri(McGregor)对常用杀螨剂的抗性水平,本研究采用阿维菌素、哒螨灵、三唑锡、螺螨酯4种不同类型杀螨剂对柑橘全爪螨重庆北碚种群、璧山种群、武隆种群和忠县种群进行了田间敏感性测定。结果表明,柑橘全爪螨4个种群对三唑锡表现最不敏感,致死中浓度LC50在209.9～370.9mg/L之间。璧山种群对阿维菌素敏感性最高,武隆种群和忠县种群对阿维菌素的相对抗性分别达12倍和11倍。哒螨灵监测结果表明,北碚种群的抗性水平显著高于其他3个种群。而北碚种群对螺螨酯的LC50仅为1.2mg/L,显著低于其他种群。柑橘全爪螨4个种群解毒酶活性研究发现,解毒酶活性的高低与不同种群抗性水平之间并没有明显相关性,这可能同各地区施药背景不同、综合防治措施不同、各杀螨剂作用机理不同、不同种群体内代谢抗性及靶标抗性水平差异有关。

Susceptibility to acaricides and detoxification enzyme activity of four field populations of Panonychus citri

The susceptibility of four Chongqing populations of the citrus red mite Panonychus citri（McGregor）to four commonly used acaricides,abamectin,azocyclotin,pyridaben and spirodiclofen,was investigated.The results show that all four populations were least sensitive to azocyclotin,with LC50 values ranging from 209.9 to 370.9 mg/L,relative to the other three acaricides.The Bishan population exhibited the highest level of sensitivity to abamectin;LC50 values of the Wulong and Zhongxian populations were 12-and 11-times higher than that of Bishan population.Although the Beibei population had significantly higher resistance to pyridaben,it had a low LC50value to spirodiclofen.Investigation of the activities of the main detoxification enzymes （cytochrome P450 momooxygenases,glutathione S-transferase,carboxylesterase） indicated that there was no significant correlation between resistance levels and detoxification enzyme activity.These could possibly be caused by different strategies of applying acaricides in the field,differences in mode of action between different acaricides and different resistance mechanisms in the four populations.