不同温度和浓度下核型多角体病毒对甜菜夜蛾的致病力

于室内测定了不同温度下核型多角体病毒对甜菜夜蛾的致病力和不同浓度核型多角体病毒对甜菜夜蛾致病力的影响。结果表明,在（25±1）℃条件下,病毒浓度为1×107PIBs/mL、1×106PIBs/mL、1×105PIBs/mL、1×104PIBs/mL、1×103PIBs/mL时,甜菜夜蛾3龄幼虫感染10d后的累计死亡率分别为83.3%,83.3%,86.7%,90.3%,96.7%,但处理间差异不显著。温度显著影响甜菜夜蛾病毒的致病力。病毒浓度为1×106PIBs/mL时,在30℃和35℃下,甜菜夜蛾3龄幼虫感染10d后的累计死亡率均为96.7%,在15℃下仅为53.3%。在35℃,30℃,25℃,20℃,15℃下,LT50分别为5.0d,4.8d,5.4d,8.8d,13.7d。

Effect of Concentration and Temperature on Pathogenicity of Spodoptera exigua Nuclear Polyhedrosis Virus

The effect of concentration of nuclear polydedrosis virus （NPV） and temperature on the pathogenicity of the NPV were studied.The results indicated that the virus pathogenicity against Spodoptera exigua was not significantly affected by the virus concentration.The accumulative mortality of the third instar larvae of S.exigua after ten days of treatment at the concentration of 1×107 PIBs/mL,1×106 PIBs/mL,1×105 PIBs/mL,1×104 PIBs/mL,1×103 PIBs/mL were 83.3%,83.3%,86.7%,90.3% and 96.7%,respectively.However,the pathogenicity of the virus was significantly varied under different temperatures.The accumulative mortality after 10 days at 30 and 35℃ at the concentration of 1×106 PIBs/mL was both 96.7%,whereas the accumulative mortality at 15℃ was only 53.3%.The LT50-value of the virus at 35℃,30℃,25℃,20℃ and 15℃ were 5.0 d,4.8 d,5.4 d,8.8 d and 13.7 d,respectively.