Temporal and spatial dynamics of resistance to some commercial insecticides in Phyllotreta striolata(Fabricius)(Coleoptera: Chrysomelidae) in Fuzhou, China

Temporal and spatial dynamics of resistance to some commercial insecticides were detected by leaf-dipping technique in the field populations of the striped flea beetle Phyllotreta striolata(Fabricius). Compared with the relatively susceptible population which was reared in the field insectarium for six generations under insecticide-free condition, different resistance levels to conventional insecticides, including dichlorvos, chlorpyrifos, phoxim, acephate, carbosulfan, fenvalerate, cypermethrin, beta-cypermethrin, delamethrin, lambdacyhalathrin and fipronil, were found in the field populations of P.striolata collected from Jianxin and Hongtang of Fuzhou, and Jingxi of Minhou, Fujian, China, respectively. The levels of resistance to the insecticides among the field populations of P.striolata from the three vegetable districts were significantly different. Meanwhile, great variations of resistance to dichlorvos, fenvalerate and cypermethrin were found in different seasons by field monitoring from Nov. 2001 to Jan. 2003 in Jianxin population of P.striolata. In addition, the strategy of resistance management was discussed based on the results of resistance monitoring.