Isolation, identification and virulence of Beauveria bassiana from a dead Homona coffearia

Through a series of cultivations and purifications,a pathogenic fungus was isolated from the dead body of a Homona coffearia Meyrick in a tea plantation.It was subsequently identified to be Beauveria bassiana by means of rDNA-ITS sequencing,and named JYBb201.The colony diameter and sporulation of JYBb201 on three media(i.e.,PDA,PPDA and SDAY)were observed.The results showed that the JYBb201 colonies grew fastest on PDA among the three media with a daily increase of 4.3 mm in diameter.However,the highest sporulation occurred on SDAY after cultivation for 16 days.The virulence of JYBb201 was tested by treating H. coffearia larvae with a suspension of fungal spores at five concentration levels.When the larvae were dealed with a suspension of fungal spores with 2.16?108mL-1 and 4.32?107mL-1 respectively,the two corrected mortalities of larvae were both 94.74% after 9 days.The results indicated that JYBb201 could be a potential pathogenic microorganism for controlling the pest.