球孢白僵菌对烟蚜茧蜂生命参数及控害效果的影响

在室内评价了球孢白僵菌对烟蚜茧蜂生命参数及控害效果的影响。分别在烟蚜茧蜂寄生桃蚜后不同时间进行高剂量(1900孢子/mm2)接菌,检测蚜虫感病率和寄生蜂形成的僵蚜率及僵蚜出蜂率。结果表明,球孢白僵菌对僵蚜率和僵蚜出蜂率的影响随接菌时间不同而变化。在烟蚜茧蜂寄生前1d、寄生当天和寄生后3d接菌,蚜虫感病率分别为59.6%、56.2%和34.8%;与对照相比,僵蚜率分别下降94%、59%和47%,僵蚜出蜂率分别减少83%、54%和49%。在寄生后5d或7d接菌,僵蚜率和僵蚜出蜂率不受明显影响,但蚜虫感病率降低到8.2%以下。对蚜尸内白僵菌菌体含量检测表明,随着烟蚜茧蜂寄生后接菌时间的推移,菌体数量迅速下降。寄生蜂寄生后5d或7d接菌,蚜尸内几乎检测不到菌体。直接喷雾接菌烟蚜茧蜂,成蜂寿命缩短4d左右,且81.8%的蜂尸受白僵菌感染。接菌后的寄生蜂对蚜虫寄生率几乎无影响,但寄生蜂在蚜虫体内的存活时间缩短了27.8%。

Impacts of Beauveria bassiana on life parameters and control efficiency of Aphidius gifuensis

Impacts of Beauveria bassiana on life parameters and control efficiency of Aphidius gifuensis were assessed in laboratory. The groups of aphids were sprayed with B. bassiana at the dose of 1900 conidia /mm2 at different stages of parasitism,and both mycosis infection rate or mummification rate of Myzus persicae and emergence rate of A. gifuensis from mummified aphids were recorded. The results suggested that mycosis in treated aphids or mummies,as well as adult emergence of A. gifuensis was significantly affected,varying with inoculation time of the fungal spores. Compared to the control spraying with 0.05% ( v/v) Tween-80 only,fungal inoculation at 1 day before,the same day and 3 days after A. gifuensis parasitization,caused about 59.6%,56.2% and 34.8% aphids being infected,and reduced mummification rate by 94%,59% and 47% and emergence rate of mummified aphids by 83%,54% and 49%,respectively. However,spraying B. bassiana at 5 or 7 days after A.gifuensis parasitization,little impaction on mummification and emergence of A. gifuensis from mummified aphids were observed,yet mycosis infection rate was reduced to less than 8.2%. The fungal infection was almost undetected in mummified aphids at 5 or 7 days after A. gifuensis parasitization. When A. gifuensis adults ware sprayed with the fungal conidia,their life-span was shortened about 4 days as compared with control,and approximately 81.8% parasitized cadavers were infected by B. bassiana. The parasitic rate of A. gifuensis adults sprayed with the fungal conidia was not significantly affected,but the survival duration of them in parasitized aphids was shortened by 27.8%.