绿僵菌与3种杀虫剂混配对樟巢螟的协同作用

Synergistic effects of Metarhizium mixed with three pesticides against Orthaga achatina

采用定量喷雾法测定了绿僵菌、白僵菌以及3种杀虫剂对樟巢螟Orthaga achatina低龄幼虫的室内毒力,并测定了金龟子绿僵菌Ma09与3种杀虫剂混配后的协同作用。结果显示:4种昆虫病原菌菌株均对樟巢螟2~3龄幼虫具有较好的致死效果,用绿僵菌和白僵菌孢悬液处理后,死亡高峰期在3~4 d;白僵菌GDLY9的防治效果最好,处理浓度为1×109孢子/mL下LT50和LT90分别为3.01 d、3.95 d,金龟子绿僵菌Ma09、3297效果相当,黄绿绿僵菌Mf985的LT50相对低一些,但是LT90优于金龟子绿僵菌Ma09和3297。金龟子绿僵菌Ma09与苯氧威、除虫脲和短稳杆菌混配后均表现出增效作用,协同指数分别为20.43、27.53和33.13。

The bioassay of Metarhizium,Beauveria and three pesticides to Orthaga achatina was measured by quantitative spray method,and the synergistic effect of Ma09 mixed with three chemical agents was determined.The results showed that all the four kinds of entomopathogenic fungi had better lethal effect on the second instar larvae of O.achatina.After treatment with suspension of Metarhizium and Beauveria,the peak of death was observed at 3~4 days.The control effect of GDLY9 was the best,LT50 and LT90 were 3.01 d and 3.95 d at the concentration of 1×109 spores/mL,respectively.The effects of Ma09 and the strain of 3297 were similar,while LT50 of Mf985 was relatively low,but LT90 was better than that of Ma09 and 3297.The combination of Ma09 with fenoxycarb,diflubenzuron and Empedobacter brevis showed synergistic effect,and the cooperativity indexes were 20.43,27.53 and 33.13,respectively.