关键词: 棉铃虫核型多角体病毒, 化学杀虫剂, 大豆卵磷脂, 增效作用, 解毒酶活性

Abstract: Thirdinstar larvae of Helicoverpa armigera were fed on artificial diet mixed with combinations of H.armigera nucleopolyhedrovirus (HaNPV) and insecticides——cyhalothrin, deltamethrin, esfinualerate, mijinthrin, methomyl, phoxim, methylparathion and acephate respectively. Mortalities were observed，and LC₅₀ values and the synergic ratio were determined. The activities of three enzymes (Mixedfunction oxidase, MFO; Carboxylesterase, CarE; Acetylcholinesterase, AChE) in relation to the pest resistance to insecticides were also detected. In addition,enhancement of HaNPV infectivity by soybean lecithin was revealed. The results showed that combination of HaNPV and each of the insecticides was more effective than HaNPV or insecticides alone, all the synergic ratios were mere than 1.0, especially synergic ratio of HaNPVmethylparathion treatment arrived at 3.53. The activities of MFO in resistant H.armigera larvae treated with mixtures of HaNPV and insecticides decreased 3～27 times as compared to insecticide treatments alone. The activities of CarE and AChE in the resistant larvae treated with the mixtures were lower than that with insecticides alone as well. NPV inhibited the increase of MFO and CarE activity induced by insecticides. Lecithin enhanced the infectivity of HaNPV against H.armigera larvae, the LT₅₀ value of HaNPV was shorten when the lecithin was combined.

Key words: H.armigera nucleopolyhedrovirus, chemical insecticide, soybean lecithin, synergism, enzyme activity