Khan Hafiz Azhar Ali, Akram Waseem, Khan Tiyyabah, Haider Muhammad Saleem, Iqbal Naeem, Zubair Muhammad
Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
Department of Entomology, University of Agriculture, Faisalabad, Pakistan.
Chemosphere. 2016 May;151:133-7. doi: 10.1016/j.chemosphere.2016.02.077. Epub 2016 Mar 15.
Reduced sensitivity to insecticides in insect pests often results in control failures and increases in the dose and frequency of applications, ultimately polluting the environment. Reduced sensitivity to emamectin benzoate, a broad-spectrum agrochemical belonging to the avermectin group of pesticides, was reported in house flies (Musca domestica L.) collected from Punjab, Pakistan, in 2013. The aim of the present study was to investigate the risk for resistance development, biochemical mechanism, and cross-resistance potential to other insecticides in an emamectin benzoate selected (EB-SEL) strain of house flies. A field-collected strain showing reduced sensitivity to emamectin was re-selected in the laboratory for five consecutive generations and compared with a laboratory susceptible (Lab-Susceptible) reference strain, using bioassays. The field strain showed rapid development of resistance to emamectin (resistance ratio (RR) increased from 35.15 to 149.26-fold) as a result of selection experiments; however, resistance declined when the selection pressure uplifted. The EB-SEL strain showed reduction in resistance to abamectin, indoxacarb, and thiamethoxam. The results of synergism experiments using piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) enzyme inhibitors and biochemical analyses revealed that the metabolic resistance mechanism was not responsible in developing emamectin resistance in the EB-SEL strain. In conclusion, the risk for the rapid development of emamectin resistance under continuous selection pressure suggests using a multifaceted integrated pest management approach for house flies. Moreover, the instable nature of emamectin resistance in the EB-SEL strain and lack of cross-resistance to other insecticides provide windows for the rotational use of insecticides with different modes of action. This will ultimately reduce emamectin selection pressure and help improving management programs for house flies without polluting the environment.
害虫对杀虫剂的敏感性降低常常导致防治失败，并增加用药剂量和频率，最终污染环境。2013年在巴基斯坦旁遮普采集的家蝇（Musca domestica L.）中报告了对甲氨基阿维菌素苯甲酸盐（一种属于阿维菌素类农药的广谱农用化学品）的敏感性降低。本研究的目的是调查在甲氨基阿维菌素苯甲酸盐选择（EB-SEL）的家蝇品系中对其他杀虫剂产生抗性的风险、生化机制和交叉抗性潜力。通过生物测定法，对一个田间采集的对甲氨基阿维菌素敏感性降低的品系在实验室连续五代进行重新选择，并与实验室敏感（实验室敏感）参考品系进行比较。由于选择实验，田间品系对甲氨基阿维菌素的抗性迅速发展（抗性比（RR）从35.15增加到149.26倍）；然而，当选择压力解除时，抗性下降。EB-SEL品系对阿维菌素、茚虫威和噻虫嗪的抗性降低。使用胡椒基丁醚（PBO）和S,S,S-三丁基磷酸三硫酯（DEF）酶抑制剂的增效实验结果和生化分析表明，代谢抗性机制与EB-SEL品系中甲氨基阿维菌素抗性的产生无关。总之，在持续选择压力下甲氨基阿维菌素抗性快速发展的风险表明，应对家蝇采用多方面的综合害虫管理方法。此外，EB-SEL品系中甲氨基阿维菌素抗性的不稳定性质以及对其他杀虫剂缺乏交叉抗性为轮换使用具有不同作用方式的杀虫剂提供了机会。这最终将降低甲氨基阿维菌素的选择压力，并有助于在不污染环境的情况下改进家蝇管理方案。
