甜菜夜蛾核型多角体病毒的致病力测定与群养对病毒产量的影响

Bioassay of Spodoptera exigua Nuclear Polydedrosis Virus and Effect of Different Larvae Density on SeNPV Yield

以3龄中甜菜夜蛾幼虫为试虫,测定出甜菜夜蛾核型多角体病毒的半致死浓度(LC50)为1.66×105PIB/mL,计算出1×108PIB/mL、1×107PIB/mL、1×106PIB/mL3种浓度的半致死时间(LT50)分别为3.95d,4.47d,5.35d;研究了甜菜夜蛾群养条件对病毒产量的影响,确定出感染浓度为1×108PIB/mL、感染龄期为5龄初幼虫、饲养密度为30头/dm2时获得的病毒产量最高。

Bioassay method was used to study the pathogenicity of Spodoptera exigua nuclear polydedrosis virus （SeNPV） to the middle 3th-instar larvae of S.exigua.The results demonstrated that LC50 of SeNPV to S.exigua was 1.66×105 PIB/mL.The results also showed LT50 was 3.95 days,4.47 days and 5.35 days when the concentrations of 1×108 PIB/mL,1×107 PIB/mL,1×106 PIB/mL were used respectively.Furthermore,the effect of larval stadium and larval population density on multiplication was also studied.It is showed that greatest production of SeNPV could be obtained when the early 5th-instar larvae are infected by concentration of 1×108 PIB/mL and reared with the density of 30 larvae per square decimeter.