蜡蚧轮枝菌昆明菌株（KM9803）对几种蚜虫的室内毒力测定

 蜡蚧轮枝菌昆明菌株（KM9803）对3种供试蚜虫都有较强的致病力。将3种蚜虫的无翅成蚜用1.0×10⁴～1.0×10⁸分生孢子/mL悬浮液处理后，测得该菌株分生孢子对3种蚜虫的致死中浓度LC₅₀ 分别是3.75×10⁴孢子/mL（桃蚜Myzus persicae）,2.74×10⁴孢子/mL（白尾红蚜Uroleucon formosanum）和0.68×10⁴孢子/mL（麦无网蚜Acythosiphon dirhodum）；但芽生孢子对桃蚜的毒力却较强（LC₅₀ 1.87×10⁴孢子/ml）。当用1.0×10⁸孢子/mL浓度的分生孢子悬浮液处理时，对3种蚜虫的致死中时间LT₅₀分别是4.7d(白尾红蚜),3.6d(桃蚜)和3.6d(麦无网蚜)；而用1.0×10⁵孢子/mL浓度的分生孢子悬浮液处理时，LT₅₀分别为6.7d(白尾红蚜),6.0d(桃蚜)和4.9d(麦无网蚜)。

The Toxicity Bioassayed of Verticillium lecanii KM9803 Strain Against Three Species Aphides in Laboratory

KM9803 strain of Verticillium lecanii（Zimm）Viegas was isolated from diseased aphide on Brevicoryne brassicae in plastic shed greenhouse in Kunming in 1998. The toxicity of KM9803 against three species aphide(apterous adult) bioassyed under controlled condition in the laboratory. Aphide were immersed in conidial suspensions at concentration ranging from 1.0×10⁴~1.0×10⁸ conidial/mL, The results show that the LC₅₀ of conidiospores on Myzus persicae，Uroleucon formosanum and Acythosiphondirhodumwere 3.75×10⁴, 2.74×10⁴ and 0.68×10⁴(conidial/mL),respectively. For blastospores on M. persicae, the LC₅₀ was 1.87×10⁴ conidial/mL. The LT₅₀ of conidiospores at 1.0×10⁸ conidial/mL, were 3.6d（M. persicae）, 4.7d (U. formosanum) and 3.6d (A.dirhodum), respectively, while at 1.0×10⁵ conidial/mL the values were 6.0d (M. persicae), 6.7d (U. formosanum) and 4.9d (A. dirhodum).