球孢白僵菌MZ041016菌株与4种低剂量农药混用对甘蓝蚜虫的室内毒力测定

通过室内测定球孢白僵菌(Beauveria bassiana)MZ041016菌株不同浓度孢子及与不同农药混配对甘蓝蚜(Brevicoryne brassicaeL)的毒力,探讨球孢白僵菌的致病力及其开发潜力。结果表明,球孢白僵菌在9.2×108,9.2×107,9.2×106,9.2×105,9.2×104和9.2×103个/mL 6种浓度梯度下对甘蓝蚜具有致病作用,其中,浓度为9.2×108和9.2×107个/mL悬浮液对甘蓝蚜有较高致死率,其第7天死亡率达到100%;浓度为9.2×103个/mL死亡率最低为48.61%。生测结果表明,9.2×108个/mL悬浮液与不同农药混配对甘蓝蚜均具有较强的毒力,其中稀释10倍,以乐斯本的死亡率为最高,第5天可达100%;其次是灭多威、阿维菌素,吡虫啉死亡率最低,第6天仅达78.16%;稀释100倍,仍以乐斯本的死亡率最高,第5天达到73.41%,其次是灭多威、阿维菌素,吡虫啉死亡率为最低,第6天达54.57%。

Toxicity Determination of Beauveria bassiana MZ041016 Mixed with Four Insecticides to Brevicoryne brassicae L

The results of toxicity determination in laboratory showed that Brevicoryne brassicae L was highly infected at the doses of 9.2×108,9.2×107,9.2×106,9.2×105,9.2×104 and 9.2×103 conidia/mL,the mortality was 100% at 7th day afuer inoculation at the concentration of 9.2×108 and 9.2×107 conidia/mL,respectively,and was 48.61% at the level of 9.2×103 conidia/mL.The bioassay indicated that B.bassiana at 9.2×108 conidia/mL mixed with different pesticides had stronger virulence to Brevicoryne brassicae L;with 10 fold dilution of insecticides at the 5th day,the mortality of Lorsban48EC was 100%,secondly came Methomy and Abamectin1.8%WP and Imidacloprid was the last with 78.16% mortality at the 6th day;with 100 fold dilution,the mortality of Lorsban48EC was the highest and was 73.41% at the 5th day,Methomy and Abamectin1.8%WP ranked next and Imidacloprid came the last with 54.57% mortality at 6th day.