甘蓝夜蛾核型多角体病毒对主要夜蛾科害虫生物活性的测定

文章测定甘蓝夜蛾核型多角体病毒(Mabr NPV)对农业生产中5种主要夜蛾科害虫幼虫的毒力。结果表明,MabrNPV对斜纹夜蛾、甜菜夜蛾、棉铃虫、粘虫、小地老虎幼虫均有致病性,但致病力存在差异,其对五种夜蛾科害虫2龄幼虫致死中浓度LC_(50)分别为1.19×10~5、2.02×10~5、4.30×10~5、2.15×10~6、1.29×10~(16)PIB·mL~(-1),MabrNPV对斜纹夜蛾和甜菜夜蛾毒力最高,对小地老虎毒力最低,对斜纹夜蛾和甜菜夜蛾与其他3种夜蛾毒力差异显著。对斜纹夜蛾和甜菜夜蛾幼虫毒力随虫龄增加而降低,幼虫对病毒易感性随虫龄增加而下降。在同一饲毒浓度下,MabrNPV对斜纹夜蛾和甜菜夜蛾幼虫致死中时间LT_(50)随虫龄增加而升高;同一虫龄下,LT_(50)随MabrNPV浓度增加而减少。

Biological activity assay of main Noctuida noctuidae pests on MabrNPV

In the paper,bioassay methods were used to MabrNPV to virulence of five important species of noctuidae in agricultural production.Research indicated that MabrNPV could infect Spodoptera litura,Spodoptera exigua,Helicoverpa armigera,Mythimna separate and Agrotis ypsilon.But there were differences in pathogenicity,the lethal concentration LC50 was 1.19x105,2.02x105,4.30x 105,2.15x 106 and 1.29x 1016 PIB· mL-1 separately.The virulent of MabrNPV to Spodoptera litura and Spodoptera exigua larvae was higher,virulence to Agrotis ypsilon was the lowest.There was no significant difference between Spodoptera litura and Spodoptera exigua in pathogenicity,but the difference was significant compared with the other three kinds of noctuidae pests.The virulence of MabrNPV was stronger to low instar larvae of Spodoptera litura and Spodoptera exigua and weaker to elder larva.The median lethal time(LT50) to Spodoptera litura and Spodoptera exigua elder larva was longer with the same concentration of MabrNPV.Nuder the same larva instar,the LT50 was become shorter in a concentration-dependent of MabrNPV.