作　　者： ; ; ; ; ; ;

机构地区： 华南农业大学

出　　处： 《生态学报》 2005年第10期2582-2588,共7页

摘　　要： 在室内研究了分离自小猿叶甲的一株球孢白僵菌(SCAU-BB01D)对小猿叶甲的致病力.结果表明,该菌株能感染小猿叶甲的成虫和各龄幼虫,但对不同虫期的致病力存在差异.在105～108孢子/ml的浓度范围内,随着处理浓度的升高,各虫期小猿叶甲的感病死亡率增加,在最高浓度1×108孢子/ml,处理后成虫第14天及1～3龄幼虫第10天的累计死亡率分别为84.7%、94.0%、96.0%和81.0%.用TDM模型对成虫和各龄幼虫的致病力数据进行模拟,所建模型均顺利通过Hosmer-Lemeshow拟合异质性检验,表明模型拟合良好,并由模型估计出了该菌株对小猿叶甲各虫期的致死剂量与致死时间.在处理后第10天,成虫和1～3龄幼虫的致死中浓度(LC50)分别为2.68×107、1.07×106、1.63×105孢子/ml和8.31×106孢子/ml,而第14天成虫的LC50为2.38×106孢子/ml.随着浓度的增加,各虫期所需的感病死亡时间缩短,在最高浓度1×108孢子/ml,球孢白僵菌对小猿叶甲成虫及1～3龄幼虫的致死中时(LT50)分别为9.28、4.29、4.40d和5.06 d.综合分析白僵菌对各虫期的致死剂量及致死时间可以看出,不同虫期的小猿叶甲对球孢白僵菌敏感性不同.结果表明该菌株在小猿叶甲生物防治中具有一定的潜力. The daikon leaf beetle, Phaedon brassicae, is an important insect pest of cruciferous vegetables in South China. It is typically controlled by synthetic insecticides. A search was made for alternative control methods, and diseased daikon leaf beetles were collected and screened for potentially useful pathogens. A Beauveria bassiana isolate, SCAU-BB01D, originally derived from P. brassicae adults was found to infect all stages of the beetle under laboratory conditions. The pathogenicity of the isolate was investigated by immersing P. brassicae larvae and adults into serial dilutions of B. bassiana （10^5-10^8 conidia/ ml ）. The highest concentration （10^8 conidia/ml） treatment caused an adult mortality of 84.7% on day 14, and larval mortalities of 94.0%, 96.0%, and 81.0% for instars Ⅰ, Ⅱ , Ⅲ on day 10, respectively. A time-dose-mortality model was used to analyze the bioassay data and the model fitted the data well, resulting in parameters for estimating the time and dose effects, The LC50 values of instar Ⅰ- Ⅲ and adult were 1.07 × 10^6 , 1.63 × 10^5 , and 8.31× 10^6 , 2.68 × 10^7 conidia/ml, respectively, on day 10 after treatment. The LC50 value on day 14 was 2.38× 10^6 conidia/ml for adults. The lethal time for the isolate on P. brassicae varied with the insect stage. At a concentration of 10^8 conidia/ml, the LT5o values of the isolate against adult and instar Ⅰ, instar Ⅱ, and instar Ⅲ larvae were 9.28, 4.29, 4.40 and 5.06 d, respectively. The results indicated the potential of the isolate for use in microbial control of P. brassicae.

关 键 词： 球孢白僵菌 小猿叶甲 致病力 生物防治

领　　域： [生物学] [生物学]