褐飞虱对吡虫啉的田间抗性动态分析

Dynamics in imidacloprid resistance in field population of Nilaparvata lugens (Hemiptera:Delphacidae)

连续对南京、吴江和安庆3个地理种群的褐飞虱进行了吡虫啉的抗性动态监测,并对相关的室内筛选品系进行了适合度分析。结果显示:虽然2005年以来国内已经较少使用吡虫啉防治褐飞虱,但褐飞虱对吡虫啉的抗性并没有显著下降(由26.6～147.8倍到37.4～87.3倍)。然而通过构建褐飞虱不同品系的实验种群生命表发现,褐飞虱对吡虫啉产生抗性后,其适合度显著下降,仅为敏感品系的0.191,表明褐飞虱杂合种群对吡虫啉的抗性具有不稳定性,在不接触药剂的情况下,田间抗性会逐步下降。对这一矛盾现象的讨论分析认为,目前田间褐飞虱对吡虫啉抗性没有显著下降的原因,一方面是局部地区还在使用吡虫啉,主要用于早期防治白背飞虱;另一方面目前使用的某些替代防治药剂可能与吡虫啉具有某种交互抗性关系。

Three field populations （Nanjing Jiangsu,Wujiang Jiangsu,Anqing Anhui） were continuously monitored in different years,and some related strains were also subjected to fitness analysis in this work.The results showed that imidacloprid resistance in field populations of brown planthopper （BPH） （RR 37.4-87.3） had not changed much as compared with that in 2005 （RR 26.6-147.8）,though imidacloprid had been limited to use for controling this pest for 3 years.However,the study with life tables demonstrated that the resistant strain exhibited very low relative fitness （0.191）.This means that imidacloprid resistance was unstable in heterozygous populations.When insecticide sprays were suspended,BPH could recovery its susceptibility to imidacloprid.Discussion found that two possible reasons could explain why no susceptibility recovery was found in the field population of BPH.Firstly,imidacloprid was still used somewhere,especially for control of the white-backed plant hopper in the early season,which could sustain the imidacloprid resistance of BPH.Secondly,the substitute insecticides could have some cross-resistance with imidacloprid.