Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Pest Manag Sci. 2010 Jun;66(6):676-85. doi: 10.1002/ps.1929.
Imidacloprid is the primary insecticide for controlling the tobacco-adapted form of the green peach aphid (TGPA), Myzus persicae (Sulzer), a major pest of tobacco worldwide. This study used leaf-dip bioassays to assess TGPA resistance to imidacloprid in the eastern United States from 2004 through 2007.
When combined over the 4 year study, 18, 14 and 3% of the TGPA had imidacloprid resistance ratios (RRs) of 10-20-fold, 20-30-fold and 30-90-fold, respectively, compared with the most susceptible colony tested. This indicates that some colonies have developed moderate levels of resistance to imidacloprid. A colony collected near Clayton, North Carolina, had the highest RR of 91 (LC(50) value = 31 mg L(-1)). This resistance declined for six tests over a 3 year period in the laboratory culture from >130-fold RR (LC(50) = 48 mg L(-1)) to 40-fold RR (LC(50) = 15 mg L(-1)). Over the same period, the most susceptible colony and a standard colony not exposed to imidacloprid for over 7 years had consistently low LC(50) values.
Moderate levels of resistance to imidacloprid are noticed among TGPA colonies from the eastern United States. The variation in resistance indicates that the factors responsible are present in the populations at low frequencies and are just not enough to cause field failures yet.
吡虫啉是防治适应烟草的绿桃蚜（TGPA），烟蚜（Sulzer），一种世界性的烟草主要害虫的主要杀虫剂。本研究采用叶浸生物测定法评估 2004 年至 2007 年美国东部 TGPA 对吡虫啉的抗药性。
当结合 4 年的研究时，18、14 和 3%的 TGPA 对吡虫啉的抗性比值（RR）分别为 10-20 倍、20-30 倍和 30-90 倍，与测试的最敏感的群体相比。这表明一些群体对吡虫啉产生了中等水平的抗性。在北卡罗来纳州克莱顿附近收集的一个群体具有最高的 RR91（LC（50）值= 31 毫克/升）。这种抗性在实验室培养中经过 3 年的 6 次测试从> 130 倍 RR（LC（50）= 48 毫克/升）下降到 40 倍 RR（LC（50）= 15 毫克/升）。在同一时期，最敏感的群体和一个未接触过超过 7 年的标准群体的 LC（50）值一直很低。
美国东部 TGPA 群体对吡虫啉的抗性处于中等水平。抗性的变化表明，这些因素在种群中的存在频率较低，还不足以导致田间失效。
