Studies On The Investigation And Isolation Of Pathogenic Fungi Of Emerald Ash Borer Agrilus Planipennis (Coleoptera: Buprestidae)

To establish the biological control technology of Emerald Ash Borer (EAB), Agrilus planipennis Fairmaire, which is a destructive borer of Fraxinus trees, the investigation and isolation of EAB pathogenic microorganism were studied. The results showed that there is 6.3% dead larvae caused by infection of pathogenic fungi in EAB nature population, no finding that of pathogenic bacteria or virus. After the dead EAB larvae samples were cultivated keeping in wet condition, six purified fungi strains had been gotten isolated from those samples. Through back-inoculating experimentation, fungus strain D04 was found to be pathogenic to EAB larvae and it was identified as Verticillium sp. of Moniliaceae family in Moniliales, Hyphomycetales, Deuteromycotina. From bioassay, it was known that Verticillium sp. strain D04 has the effective control to either EAB larvae or its adults, and the LC50 to the larvae is 7.29×10~8 spores/ml .In 1×10~9spores /ml inoculating concentration, Verticillium sp. strain D04 caused 75% mortality rate of EAB larvae, and the fatal time is 18 days; To adults of EAB, the mortality rate is 85.71% and the fatal time is just 9 days. This research's isolating the pathogenic verticillium sp. strain D04 of EAB firstly, and its more effective infection to EAB adults compared with that of it to larvae is beneficial to the study of biological control technology of EAB.