球孢白僵菌对烟蚜茧蜂寄生行为的影响

室内评价了一株球孢白僵菌Bb0062对天敌昆虫烟蚜茧蜂寄生行为的影响。直接喷雾接菌进行生物测定,结果表明,球孢白僵菌对烟蚜茧蜂具有较高毒性,随着接种剂量的增加,致死中时(LT50)缩短。利用烟蚜茧蜂寄生接菌和未接菌的桃蚜,发现寄生蜂对健康桃蚜的寄生率为52.54%,明显高于对接菌桃蚜的寄生率40.19%,表明球孢白僵菌可通过侵染蚜虫间接影响寄生蜂的寄生行为。以喷雾接菌当天(0天)、1、3和5天的寄生蜂寄生桃蚜,寄生率分别比对照下降21.0%、17.2%、33.3%和30.4%,寄生时间分别比对照下降35.9%、38.7%、53.1%和39.7%。由此表明,球孢白僵菌对烟蚜茧蜂的寄生行为有不利影响。

Impacts of Beauveria bassiana

Effects of a strain of entomopathogenic fungus Beauveria bassiana,Bb0062 on parasitic behavior of aphid parasitoid Aphidius gifuensis was evaluated in laboratory.The bioassay indicated that B.bassiana had high virulence on A.gifuensis,and LT50s of the parasitoid shorted with increasing conidia doses sprayed.The aphid sprayed fungus or 0.05% Tween-80 was used to rear A.gifuensis and results showed that parasitic rate of the parasitoid to healthy aphid(52.54%)was significantly higher than that to aphid sprayed fungus(40.19%),which suggested that the fungus could influence the parasitic behavior of the parasitoid by infecting its host aphid.On 0,1,3,and 5 days after fungus exposure,the parasitic rate of A.gifuensis adults was decreased by 21.0%,17.2%,33.3% and 30.4%,and parasitic time of the parasitoid was shorted by 35.9%,38.7%,53.1% and 39.7% compared to the control,respectively.Based on these results,it suggested that B.bassiana has adverse effect on parasitic behavior of parasitoid A.gifuensis.