扬州地区水稻二化螟对杀虫单的抗药性研究

采用毛细管点滴法监测江苏扬州(1985～2001)和兴化(1985～1994)水稻二化螟虫群对杀虫单的抗药性。结果表明：1994前,两地虫群对杀虫单的抗性水平相似,抗性倍数在10左右,且年度间变化较小;扬州虫群的抗药性2001年是1985年的5．6倍;二化螟对杀虫单的敏感性变化,与敌百虫、甲胺磷和对硫磷相同。1985～1996年的13年间,用杀虫单主治二化螟,年仅用药1次,二化螟对杀虫单的敏感性相对稳定;1996年以后,年用杀虫单增至3～5次,因选择压增加．二化螟的抗药性迅速上升。

Resistance of the Rice Stem Borer Chilo suppressalis Walker to Monosultap in Yangzhou District

The resistance of rice stem borer ( Chilo suppressalis Walker) to monosultap was tested with topical application in Yangzhou (1985-2001) and Xinghua region (1985-1994), Jiangsu province. The results were as follows: the resistance level was similar between Yangzhou and Xinghua, the resistance index was all about 10, and the variance was little between years before 1994. The resistance index in 2001 was 5.6 times higher than the index in 1985 in Yangzhou. The variance of the susceptibility of rice stem borer to monosultap was the same as trichlophnus, methamidophos, and parathion. The susceptibility of rice stem borer to monosultap was stable before 1996, rice stem borer was killed by using monosultap only once every year. But because rice stem borer was serious after 1996, monosultap was used 3-5 times every year. As the selective pressure increased, the resistance of rice stem borer to monosultap was enhanced rapidly.