Abstract: During 2001 and 2002, resistance to four insecticides in different populations of striped stem borer, Chilo suppressalis (Walker), collected from Zhejiang, Jiangsu, Anhui and Jiangxi Provinces, was monitored by topical application. Low level of resistance to fipronil (6.5-fold) was detected in Rui’an population from southeast Zhejiang, which is the first documentation of fipronil resistance in this pest insect, but other six populations tested remained susceptible to this newly introduced insecticide though some susceptibility variation existed. No apparent resistance to abamectin had been detected after examining six populations from Zhejiang, Jiangsu and Anhui Provinces, with susceptibility variation among them less than 2.3-fold. Great difference of susceptibility to triazophos was found in ten populations from the four provinces, with very high level of resistance (163.1-fold) in Rui’an population, moderate in Wenzhou (Zhejiang) population (18.2-fold), and low in populations of Changshu, Xishan and Jintan in south Jiangsu (6.7- to 9.7-fold), but the other five populations were susceptible. All nine populations monitored were resistant to monosultap with varying degrees, high level of resistance occurred in Rui’an and Yifeng (Jiangxi) populations (113.7- and 57.6-fold, respectively), moderate in Wenzhou, Changshu, Jintan and Taihu populations (11.0- to 29.7-fold), low in Xinyang and Xishan populations (6.7- and 7.5-fold, respectively), and the lowest level of resistance in Guanyun population (3.7-fold). Inheritance of triazophos resistance in Rui’an resistant strain selected with triazophos in laboratory was studied through reciprocal cross and backcross experiments. Preliminary results indicated that inheritance of resistance to triazophos in Rui’an strain was incompletely dominant,with degree of dominance (D) being 0.46 and 0.68 for reciprocal crosses, respectively, and the resistance was controlled by a single major gene, though minor modifying genes might be involved.

Key words: Chilo suppressalis, insecticide resistance, fipronil, triazophos, monosultap, abamectin, inheritance

摘要： 采用点滴法测定了2001~2002年浙、苏、皖、赣等4省水稻二化螟4龄幼虫对氟虫腈、阿维菌素、三唑磷及杀虫单等的抗性；用三唑磷高抗种群经室内筛选纯化后与室内敏感种群进行正反交、回交，对三唑磷抗性进行了初步遗传分析。结果表明：(1) 通过对4省7个种群的检测，发现浙江瑞安种群对氟虫腈有低水平抗性（抗性倍数为6.5倍），其他种群虽存在敏感度差异（1.0~1.6倍），但均属敏感范围；(2) 浙、苏、皖三省6个不同种群对阿维菌素的敏感度变化小于2.3倍，未检测到明显抗药性；(3) 4省10个种群对三唑磷敏感度变化很大（LD50值为有效成分0.0052~1.0114 μg/头），其中瑞安种群具有高水平抗性（163.1倍），温州种群为中等水平抗性（18.2倍），常熟、锡山和金坛3种群为低水平抗性（6.7~9.7倍），新洋农场、楚州、连云港、宜丰和太湖5种群为敏感（0.8~2.9倍）；(4) 4省9个种群对杀虫单均有不同程度抗药性，瑞安和宜丰种群达高水平抗性（113.7和57.6倍），温州、常熟、金坛和太湖4种群为中等水平抗性（11.0~29.7倍），新洋农场和锡山种群为低水平抗性（6.7和7.5倍），灌云种群抗性最低,为3.7倍；(5)瑞安种群对三唑磷抗性属单个主基因控制的不完全显性性状,但不排除微效修饰基因的存在。

关键词: 二化螟, 抗药性, 氟虫晴, 三唑磷, 杀虫单, 阿维菌素, 遗传