象甲虫生真菌对剪枝栎实象幼虫的毒力作用

Evaluation on Virulence of Entomogenous Fungi of Oak Nut Weevil to Larvae of Mechoris ursulus

摘要: 用从病变象甲幼虫上分离得到的14种真菌，对剪枝栎实象幼虫作毒力试验，并筛选出2株有较强致病性的菌株进行浓度梯度测试。结果表明：6号被孢霉科被孢霉属菌和7号丛梗孢科青霉属菌具有较强的致病力，致死中时分别为2203d和2941d，致死中浓度分别为303×105、284×105个/mL。

Abstract: 14 strains of entomogenous fungi were isolated from the Mechoris ursulus nymphae with pathological symptom, and these 14 strains of entomogenous fungi were employed in the virulence test against the M. ursulus nymphae. 2 of the strains, i.e., NO.6 and NO.7 with stronger infestation effect were screened out to conduct the concentration gradient test. The results showed that the median lethal time (LT50) of these two strains was 2204d and 2942d, and the median lethal concentration (LC50) of these two strains was 303×105 and 284×105 respectively.