Abstract: To provide a scientific basis for application of insecticides, spatial and temporal variations in susceptibility of N. lugens to imidacloprid were monitored by rice-stem dipping method from 42 field populations in seven provinces (autonomous region) in China from 1996 to 2006. Most field populations remained susceptible from 1996 to 2003 except for a population from Guilin, Guangxi in 1997, which showed a low level of resistance. However, the surveys in 2005 indicated that 16 populations from six provinces quickly developed the resistance to imidacloprid with resistance ratios ranged from 79-to 811-fold. The data collected in 2006 revealed that the resistance levels in 11 populations from seven different provinces decreased slightly (resistance ratios ranged from 150- to 322-fold), except Tongzhou population (Jiangsu province) which developed 627-fold resistance ratio. This phenomenon might be attributed to the temporal suspension of imidacloprid for N. lugens control. After selection for 18 generations with imidacloprid against a laboratory population of N. lugens, the resistance level of N. lugens to imidacloprid increased from 208.3- to 1110.8-fold and the realized heritability (h^2) of the resistance was estimated as 0.1414. It implied that continuous use of imidacloprid would cause further increase in the resistance level of N. lugens to imidacloprid after the high resistance level was developed. Discussion on strategies of N. lugens resistance management was also included.

Key words: Nilaparvata lugens, insecticide, susceptibility, realized heritability, insecticide resistance

摘要： 为科学用药，采用稻茎浸渍法测定了我国7省（区）42个田间褐飞虱种群对吡虫啉的敏感性时空变化。结果表明,在1996－2003年，除了1997年广西桂林种群为低水平抗性（6.3倍）外，苏、皖、桂3省13个种群对吡虫啉为敏感至敏感性下降（<5倍）；然而，2005年苏、浙、皖、赣、湘、桂6省（区）16个大田种群对吡虫啉的抗性迅速上升，达高水平至极高水平抗性（79～811倍）；2006年，除江苏通州大田种群的抗性为627倍外，苏、浙、皖、赣、湘、桂、闽7省（区）11个种群的抗性为150～322倍，比2005年有一定程度下降，这可能与暂停使用吡虫啉有关。室内用吡虫啉对褐飞虱筛选18代，其抗性由筛选前的208.3倍上升到筛选后的1110.8倍，抗性现实遗传力（h2）为0.1414。这暗示褐飞虱对吡虫啉产生高水平抗性后，如继续使用吡虫啉防治，其抗性可能会进一步上升。还讨论了稻褐飞虱抗药性的治理策略。

关键词: 褐飞虱, 杀虫剂, 敏感性, 现实遗传力, 抗药性