荧光增白剂对伊朗核型多角体病毒分离株对棉铃虫幼虫的杀虫活性的增效作用(英文)

Synergistic effects of optical brighteners on the insecticidal activities of Iranian nucleopolyhedrovirus isolates against Helicoverpa armigera ( Lepidoptera:Noctuidae ) larvae

在室内条件下调查了几种荧光增白剂对采自伊朗East-Azarbaijan的棉铃虫Helicoverpa armigera核型多角体病毒两个地域株(EAZ-I和EAZ-II)对棉铃虫2龄幼虫的杀虫活性,以提高这两个地域株的生物学活性。结果表明:与EAZ-II相比,EAZ-I的杀虫活性强,其对棉铃虫幼虫的LC50和LT50值低(分别为1.98×103OB/mL和122.7h)。本研究所用的所有荧光增白剂均能有效增强病毒的生物学活性,特别是0.2%的TinopalF-3543与EAZ-I混用对棉铃虫幼虫的LC50值最低(5.16×102OB/mL),与病毒单独应用相比活性增强了3.84倍。幼虫致死的相对速率测定结果表明,荧光增白剂提高了菌株的LT50值,其中TinopalF-3543的效果最佳。这些结果说明,在害虫综合治理中影响围食膜通透性的荧光增白剂与核型多角体病毒制剂混用是一种可供选择的重要方法。

In order to improve the biological activities （LC50 and LT50 values） of two geographic isolates of Helicoverpa armigera nucleopolyhedrovirus （EAZ-I and EAZ-II）, collected from East-Azarbaijan, Iran, some optical brighteners have been combined with the isolates under laboratory conditions to test their activity against early 2nd instar larvae of H. armigera. The results demonstrated that the EAZ-I isolate had better insecticidal activity than EAZ-II due to its lower LC50 and LT50 values of 1.98×103 OB/mL and 122.7 h, respectively. All the optical brighteners used in this study could efficiently enhance virus biological activities, especially Tinopal F-3543 in combination with EAZ-I showing the lowest LC50 at 0.2% level （5.16×102 OB/mL）, with 3.84 times higher activity than that of the virus alone. The relative speed of kill demonstrates that all the optical brighteners improved LT50 of the isolates, of which Tinopal F-3543 was identified as the most effective one. These findings suggest that the optical brighteners which target PM permeability can be considered as important alternatives to combine with HearNPV formulations in IPM programs.